DOT/FAA/AR-9 8/28

Office of Aviation Research Washington, D.C. 20591

Statis tical Loads Data for Boeing 73 7-400 Aircra ft in Commercial Operations

August 1998

Final Report

This document is available to the U.S. public through the National Technical Information Service (NTIS), Springfield, Virginia 22161.

U.S. Department of Transportation Federal A viation Admini stration

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The United States Government assumes no liability for the contents or use thereof. The United States Government does not endorse products or manufacturers. Trade or manufacturer's names appear herein solely because they are considered essential to the objective of this report.

Techni cal Report Docum entati on Pag e

1.

DOT/FAA/AR-98/28

2. Government A ccession N o. 3. alog No.

4. itle

STATISTICAL LOADS DATA FOR BOEING 737-400 AIRCRAFT IN

5.

August 1998

COMMERCIAL OPERATIONS 6. rganization Code

7.

John Rustenburg, Donal Skinn, Daniel O. Tipps

8. rganization Report No.

URD-TR-98-00032 9. rganization Name and A ddress

University of Dayton Research Institute Structural Integrity Division

10. . (TRAIS)

RPD-510-1998-00032

300 College Park Dayton, OH 45469-0120

11. Grant No.

FAA Grant No. 96-G-020 12. Agency Na me and Addr ess

U.S. Department of Transportation Federal Aviation Administration

13. ort and Peri od Covered

Final Report

Office of Aviation Research Washington, DC 20591

14. Agency Cod e

AAR-431 15. ary Notes

The Federal Aviation Administration William J. Hughes Technical Center COTR is Thomas DeFiore

16.

The University of Dayton is supporting Federal Aviation Administration (FAA) research on the structural integrity requirements for the US commercial transport airplane fleet. he primary objective of this research is to support the FAA Airborne Data Monitoring Systems Research Program by developing new and improved methods and criteria for processing and presenting large commercial transport airplane flight and ground loads usage data. The scope of activities performed involved (1) defining the service related factors which affect the operational li fe of commercial aircraft; (2) designing an efficient software system to reduce, store, and process large quantities of optical quick access recorder data; and (3) providing processed data in formats that will enable the FAA to reassess existing certif ication criteria. Equall y important, these new data will also enable the FAA, the aircraft manufacturers, and the airlines to better understand and control those factors which influence the structural integrity of commercial transport aircraft. Presented herein are analyses and statistical summaries of data collected from 11,721 flights representing 19,105 flight hours of 17 typical B-737-400 aircraft during operational usage recorded by a single airline. The statistical data presented include the initial recorded data previously reported in FAA report DOT/FAA/AR-95/21. The data include statistical information on accelerations, speeds, altitudes, flight duration and distance, gross weights, speed brake/spoiler cycles, thrust reverser usage, and gust velocities encountered.

17.

Optical quick access recorder, Flight profiles, Gust loads, Accelerations, Statistical summaries

18. Statement

This document is available to the public through the National Technical Information Service (NTIS), Springfield, Virginia 22161.

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Unclassified

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Unclassified

21. s

86

22.

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Title and Subt Report Date

Performing O

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Performing O Work Unit No

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Security Cl Security Cl No. of Page Price

Form DO T F1700.7 (8-72) Reproduct ion of completed page aut horized

PREFACE

The Flight Systems Integrity Group of the Structural Integrity Division of the University of Dayton Research Institute (URDI) performed this work under Federal Aviation Administration (FAA) Grant No. 96-G-020 entitled “Aircraft Operational Usage for Service Life Management and Design Criteria Development.” The Program Manager for the FAA was Mr. Thomas DeFiore of the FAA Willia m J. Hughes Technical Center at Atlantic City International Airport, New Jersey, and the Program Technical Advisor was Mr. Terence Barnes of the FAA Ai rcraft Certification Office. Mr. Daniel Tipps was the Principal Investigator for the University of Dayton and provided oversight direction for this effort. Mr. Donald Skinn developed the data reduction algorithms, established data reduction criteria, and performed the data reduction. Mr. John Rustenburg performed the data analysis, created the graphical presentations, and prepared the report. Ms. Andrea Snell compiled and formatted the report for publication.

iii/iv

TABLE OF CONTENTS

Page

EXECUTIVE SUMMARY xi

1. INTRODUCTION 1

2. AIRCRAFT DESCRIPTION 1

3. AIRLINE DATA COLLECTION AND EDITING SYSTEMS 2

3.1 Data Collection System 23.2 Data Editing System 3

4. UNIVERSITY OF DAYTON RESEARCH INSTITUTE DATA PROCESSING 3

4.1 Data Reduction4.2 Recorded Parameters4.3 Computed Parameters

4.3.1 Atmospheric Density4.3.2 Equivalent Airspeed4.3.3 Dynamic Pressure (q)4.3.4 Derived Gust Velocity (Ude)4.3.5 Continuous Gust Intensity (Uσ )

4.4 Data Reduction Criteria

4.4.1 Phases of Flight4.4.2 Flight Distance4.4.3 Sign Convention4.4.4 Peak-Valley Selection

4 5 6

6 7 7 7 8

9

9 11 11 12

4.4.5 Separation of Maneuver and Gust Load Factors 4.4.6 Flap Detents

5. DATA PRESENTATION

5.1 Aircraft Operational Usage Data

5.1.1 Weight Data5.1.2 Altitude Data5.1.3 Flight Distance Data5.1.4 Autopilot Usage

15

15

15

18 19 19 19

v

13

5.2 Ground Loads Data

5.2.1 Lateral Load Factor Data5.2.2 Longitudinal Load Factor Data5.2.3 Vertical Load Factor Data5.2.4 Ground Speed Data5.2.5 Flare Data5.2.6 Pitch/Rotation Data

5.3 Flight Loads Data

5.3.1 Gust Loads Data5.3.2 Maneuver Loads Data

20

20 20 20 21 21 21

21

21 22

5.3.3 Combined Maneuver and Gust Loads Data

5.4 Miscellaneous Operational Data

5.4.1 Flap Usage Data5.4.2 Speed Brake/Spoiler Usage Data5.4.3 Thrust Reverser Data5.4.4 Landing Gear Extension/Retraction Data

5.5 Propulsion System Data

6. CONCLUSIONS

7. REFERENCES

APPENDICES

A Data PresentationB Great Circle Distance Calculation

23

24 24 24 25

25

25

27

vi

22

LIST OF FIGURES

Figure Page

1 Boeing 737-400 Three-View Drawing 2 2 Airline Recording and Editing System 3 3 Description of Phases of Flight 10 4 Sign Convention for Airplane Accelerations 12 5 The Peak-Between-Means Classification Criteria 12 6a Current Acceleration Value Passes Into Deadband 13 6b Current Acceleration Value Passes Through Deadband 13

LIST OF TABLES

Table Page

1 Boeing 737-400 Aircraft Characteristics 1 2 Recorded Parameters Provided to UDRI 4 3 Parameter Editing Values 5 4 Recorded Parameters Used in Data Reduction 6 5 Phase of Flight Starting Criteria 10 6 Peak Classification Criteria 14 7 Flap Detents (B-737-400) 15 8 Statistical Data Formats 16 9 FAR Requirements for Derived Discrete Gust Velocities 23

vii

LIST OF SYMBOLS AND ABBREVIATIONS

A aircraft PSD gust response factor a speed of sound (ft/sec)

c wing mean geometric chord (ft) C aircraft discrete gust response factor CLα

aircraft lift curve slope per radian

CLmax maximum lift coeffic ient

CAS calibrated air speed c.g. center of gravity

EAS equivalent airspeed

F(PSD) continuous gust alleviation factor

g gravity constant, 32.17 ft/sec2

Hp pressure altitude, (ft)

Kg discrete gust alleviation factor, 0.88 µ /(5.3 + µ )KCAS knots calibrated air speedKEAS knots equivalent air speedKIAS knots indicated air speedkts knots

L turbulence scale length (ft)

n load factor (g)N number of occurrences for Uσ (PSD gust procedure)nm nautical milenx longitudinal load factor (g)ny lateral load factor (g)nz normal load factor (g)N0 number of zero crossings per nautical mile (PSD gust procedure)

q dynamic pressure (lbs/ft2)

S wing area (ft2)

TAS true airspeed

Ude derived gust velocity (ft/sec)

Uσ continuous turbulence gust intensity (ft/sec)

viii

LIST OF SYMBOLS AND ABBREVIATIONS (Cont’d)

VB design speed for maximum gustVC design cruise speedVD design dive speed

Ve equivalent airspeedVT true airspeed

W gross weight (lbs)

Δ m incremental acceleration due to a turning maneuver

Δ nz incremental normal load factor, nz - 1 Δ nzman

incremental maneuver load factor

Δ nzgust incremental gust load factor

/µ airplane mass ratio, 2(W S) ρ gcCLα

µ p statistical mean of p (parameter on plots)

ρ air density, slugs/ft3 (at altitude) ρ0 standard sea level air density, 0.0023769 slugs/ft3

σ p standard deviation of p (parameter on plots)

ϕ bank angle (degrees)

ix/x

EXECUTIVE SUMMARY

The University of Dayton is supporting Federal Aviation Administration (FAA) research on the structural integrity requirements for the US commercial transport airplane fleet. The primary objective of this research is to support the FAA Airborne Data Monitoring Systems Research Program by developing new and improved methods and criteria for processing and presenting large commercial transport airplane flight and ground loads usage data. The scope of activities performed involved (1) defining the service related factors which affect the operational life of commercial aircraft; (2) designing an efficient software system to reduce, store, and process large quantities of optical quick access recorder data; and (3) providing processed data in formats that will enable the FAA to reassess existing certification criteria. Equally important, these new data will also enable the FAA, the aircraft manufacturers, and the airlines to better understand and control those factors which influence the structural integrity of commercial transport aircraft. Presented herein are analyses and statistical summaries of data collected from 11,721 fli ghts representing 19,105 flight hours of 17 typical B-737-400 aircraft during operational usage recorded by a single airline. The statistical data presented includes the initial recorded data previously reported in FAA report DOT/FAA/AR-95/21. The data include statistical information on accelerations, speeds, altitudes, flight duration and distance, gross weights, speed brake/spoiler cycles, thrust reverser usage, and gust velocities encountered.

xi/xii

1. INTRODUCTION.

The Federal Aviation Administration (FAA) has an ongoing Airborne Data Monitoring Systems Research Program to collect, process, and evaluate statistical fl ight loads data from transport aircraft used in normal commercial airline operations. The objectives of this program are (a) to acquire, evaluate, and utilize typical operational in-service data for comparison with the prior data used in the design and qualification testing of civil transport aircraft and (b) to provide a basis to improve the structural criteria and methods of design, evaluation, and substantiation of future airplanes. Since the inception of the FAA’s Airborne Data Monitoring Systems Research Program, the scope of the program has steadily increased to include data collection on additional aircraft, different aircraft models, and additional operators. The University of Dayton has supported the FAA’s efforts and has responsibility for the data analysis and processing tasks and report preparation. In consultation with airplane manufacturers and operators, the University has enhanced and improved the data processing capabilities to allow reducing, analyzing, and reporting additional aircraft usage and statistical loads data from the digital fli ght loads recorders into a form that will fulfill the requests of the aircraft manufacturers, the airlines, and the FAA. The report presents data obtained from 17 airplanes over 11,721 fli ghts and 19,105 hours of airline operations for the B-737-400 aircraft of a single operator.

2. AIRCRAFT DESCRIPTION.

Table 1 presents certain operational characteristics of the 17 Boeing 737-400 aircraft which were equipped with optical quick access recorders. Figure 1 shows front, top, and side views of the aircraft and identifies its major physical dimensions.

TABLE 1. BOEING 737-400 AIRCRAFT CHARACTERISTICS

Maximum Taxi Weight Maximum Takeoff Weight Maximum Landing Weight Zero-Fuel Weight

143,000 lb 142,500 lb 121,000 lb 113,000 lb

Fuel Capacity 5311 U.S. gallons 2 CFM56-3 Engines @ 22,000 lbs static thrust each Wing Span Wing Reference Area Wing MAC Wing Sweep

94 ft 9 in 980 ft2

11 ft 2.46 in 25 degrees

Length Height Tread Wheel Base

119 ft 7 in 36 ft 6 in 17 ft 2 in 46 ft 10 in

1

FIGURE 1. BOEING 737-400 THREE-VIEW DRAWING

3. AIRLINE DATA COLLECTION AND EDITING SYSTEMS.

The airline data collection and editing system consists of two major components: (1) the data collection system installed on board the aircraft and (2) the ground data editing station. A schematic overview of the system is given in figure 2. The requirements for the data acquisition and processing are defined in reference 1. The collection and editing systems are discussed below.

3.1 DATA COLLECTION SYSTEM.

The on-board data collection system consists of a Digital Flight Data Acquisition Unit (DFDAU), a Digital Flight Data Recorder (DFDR), and an Optical Quick Access Recorder (OQAR). The DFDAU collects sensor signals and sends parallel data signals to both the DFDR and the OQAR. The OQAR is programmed to start recording once certain data signals are detected. The OQAR is equipped with an optical disk which can store up to 200 hours of flight data, whereas the DFDR uses a 25-hour looptape. The optical disk is periodically removed from the OQAR and forwarded to the ground processing station.

2

FIGURE 2. AIRLINE RECORDING AND EDITING SYSTEM

3.2 DATA EDITING SYSTEM.

The airline ground data editing station consists of a Pentium computer, a magneto-optical (MO) disk drive, and flight data editing software. The software performs a number of functions during the process of transferring the raw fli ght data into DOS file format onto the hard disk. The most important of these functions include a data integrity check and removal of flight sensitive information. Data considered sensitive are those which can be used to readily identify a specific flight. The desensitized data are forwarded to the University of Dayton Research Institute (UDRI) for fl ight loads processing and analysis. Table 2 presents the recorded data parameters provided by the airline to UDRI.

4. UNIVERSITY OF DAYTON RESEARCH INSTITUTE DATA PROCESSING.

The data parameters of table 2 are provided by the airline to UDRI for each recorded fl ight. The data are provided on magneto-optical disks containing binary files for multiple flights for different airplanes. These data are processed by UDRI to extract the parameters required for statistical flight loads presentation. This section describes the reduction of the data and the derivation of required parameters.

3

TABLE 2. RECORDED PARAMETERS PROVIDED TO UDRI

Parameter Sample Rate

Normal Acceleration 8 per second Lateral Acceleration 4 per second

Longitudinal Acceleration 4 per second Aileron Position 1 per second Elevator Position 1 per second

Rudder Position 2 per second Pilot Trim Position 1 per second Flap Handle Position 1 per second Speed Brake Position 1 per second

N1 Engine -Left 1 per second N1 Engine -Right 1 per second Throttle #1 Position 1 per second

Throttle #2 Position 1 per second Thrust Reverser Position Discrete Autopilot Status (on or off) Discrete

Squat Switch (main gear) Discrete Gear Position Discrete Calibrated Airspeed 1 per second

Ground Speed 1 per second Mach Number 1 per 4 seconds Pressure Altitude 1 per second

Gross Weight 1 per 64 seconds Bank Angle 2 per second Pitch Angle 4 per second

Magnetic Heading 1 per second Total Air Temperature 1 per second Radio Altitude 1 per second

4.1 DATA REDUCTION.

Each file provided by the airline contains multiple flights for each airplane. These files are first separated into individual flight files and subsequently into individual time history files for each flight. The time history files are compressed and stored on the same 230 MB magneto-optical disks for later recall by the flight loads processing software.

Data editing and verification are performed on the data as the time histories are being prepared. Messages alert the user that obviously erroneous data have been removed and that questionable data have been retained but need to be manually reviewed prior to their acceptance. Table 3 lists the limits against which the data are compared.

4

TABLE 3. PARAMETER EDITING VALUES

Item Condition Min Max

1. Gross Weight at start up 75,000 lbs 150,500 lbs 2. Pressure Altitude (Hp) at all times -2,000 ft 45,000 ft

3. Calibrated Airspeed at all times during flight operations 45 kts 420 kts 4. Normal Acceleration at start up and shut down in flight 0 g +4 g 5. Lateral Acceleration at all times ± 0.5 g ± 0.5 g 6. Longitudinal Acceleration at all times ± 1.0 g ± 1.0 g

7. Flap Handle Position at all times 0° 45° 8. Elevator Position at all times ± 25° ± 25° 9. Aileron Position at all times ± 25° ± 25°

10. Rudder Position at all times ± 50° ± 50° 11. Trim Position at all times 0° 20° 12. Speed Brake Handle

Position at all times 0° 60°

13. Throttles 1 and 2 at all times -5° 75° 14. Thrust Reverser Position stowed at start up and shutdown 0 1 15. Autopilot Status off or on 0 1 16. Squat Switch (main gear) closed at start up and shutdown 0 1

17. Landing Gear Position down at start up and shutdown up within 10 seconds after takeoff down within 10 minutes before landing

0 1

18. Pitch Attitude at all times -20° +30° 19. Bank Attitude at all times ± 60° ± 60° 20. Mach Number at all times 0 1

21. Ground Speed at all times 0 kts 800 kts

Important characteristics about each set of flights received from the airline are recorded in a relational database. Airline identifier, aircraft tail number, and disk identifier of the disk received from the airline are in the data. Each flight is assigned a unique flight sequence number. The flight sequence number assigned to the first flight of the set and the number of flights in the set are also entered. Also recorded is the disk identifier of the MO disk, which contains the compressed time history files of all flig hts in the set.

4.2 RECORDED PARAMETERS.

Not all parameters listed in table 2 are used for statistical analysis and data presentation. Table 4 lists the parameters used in the data reduction and for which time history files are created and compressed on the magneto-optical disk. These parameters are used by the summarization software for statistical analysis and data presentation.

5

0

TABLE 4. RECORDED PARAMETERS USED IN DATA REDUCTION

Flight Parameter Sample Rate

Gross Weight 1 per 64 seconds

Pressure Altitude 1 per second Calibrated Airspeed 1 per second Normal Acceleration (nz) 8 per second Lateral Acceleration (ny) 4 per second Longitudinal Acceleration (nx) 4 per second Flap Handle Position 1 per second Speed Brake Handle Position 1 per second Thrust Reverser Position Discrete Autopilot Status (on or off) Discrete Squat Switch (main gear) Discrete Landing Gear Position Discrete Pitch Angle 4 per second Bank Angle 2 per second Mach Number 1 per 4 seconds Ground Speed 1 per second Magnetic Heading 1 per second N1 Engine -Left 1 per second

4.3 COMPUTED PARAMETERS.

Derived gust velocity Ude and continuous gust intensity Uσ are important statistical load parameters which are derived from measured normal accelerations. This derivation of gust velocity Ude and continuous gust intensity Uσ from measured normal accelerations requires knowledge of atmospheric density, equivalent airspeed, and dynamic pressure. These values are calculated using equations that express the rate of change of density as a function of altitude based on the International Standard Atmosphere.

4.3.1 Atmospheric Density.

For altitudes below 36,089 feet, the density ρ is expressed as a function of altitude by

ρ − 1 − 4× Hp 6= ρ

o ( 6 6 .87 × 251 . 6 ) (1)

where ρ 0 is air density at sea level (0.0023769 slugs/ft3) and Hp is pressure altitude (ft). Pressure altitude is a recorded parameter.

6

4.3.2 Equivalent Airspeed.

Equivalent air speed (Ve) is a function of true air speed (VT) and the square root of the ratio of air density at altitude (ρ ) to air density at sea level (ρ 0)

Ve = VT 0ρ

ρ (2)

True airspeed is derived from Mach number (M) and speed of sound (a):

VT = Ma . (3)

Mach number is a dimensionless, recorded parameter. The speed of sound (a) is a function of pressure altitude (Hp) and the speed of sound at sea level and is

a =a0 ) H 10 6.876 (1 p 6 × × − −

(4)

Substituting equations 1 and 4 into equation 2 gives

Ve = M × a0 × (1 − 6.876 × 10− 6 × H p )0.5 × (1 − 6.876 × 10− 6 × H p )

2.128

(5)

and 2.626

Ve = M × a0 × (1 − 6.876 × 10 − 6 × H p ) (6)

where the speed of sound at sea level a0 is 1116.4 fps or 661.5 knots.

4.3.3 Dynamic Pressure (q).

The dynamic pressure (q) is calculated from the air density and velocity

q = 1 ρ V 2 (7)2

where ρ = air density at altitude (slugs/ft3) V = true air speed (ft/sec)

4.3.4 Derived Gust Velocity (Ude).

The derived gust velocity, Ude, is computed from the peak values of gust incremental normal acceleration as

Δ nzUde = (8)C

where Δ nz is gust peak incremental normal acceleration and C is the aircraft response factor considering the plunge-only degree of freedom and is calculated from

7

ρ 0V C C = e Lα

SK (9)

2W g

where

ρ 0 = 0.002377 slugs/ft3, standard sea level air density Ve = equivalent airspeed (ft/sec) CLα

= aircraft lift-curve slope per radian

S = wing reference area (ft2) W = gross weight (lbs)

Kg =0.88µ

= gust alleviation factor 5.3 + µ

2W µ = ρ gcCLα

S

ρ = air density, slug/ft3, at pressure altitude (Hp), from equation 1

g = 32.17 ft/sec2

c = wing mean geometric chord (ft)

In this program, the lift-curve slope, CLα , is the untrimmed flexible lift-curve slope for the entire

airplane. For the flaps retracted conditions, the lift-curve slope is given as a function of Mach number and altitude; for flaps extended, the lift-curve slope is a function of flap deflection and calibrated airspeed (CAS).

4.3.5 Continuous Gust Intensity (Uσ ).

Power Spectral Density (PSD) functions provide a turbulence description in terms of the probabilit y distribution of the root-mean-square (rms) gust velocities. The root-mean-square gust velocities, Uσ , are computed from the peak gust value of normal acceleration using the power spectral density technique as described in reference 2. The procedure is

Δ nzUσ = (10)A

where Δ nz = gust peak incremental normal acceleration

A = aircraft PSD gust response factor = ρ 0VeCLα S

F(PSD) in 1

(11)2W ft/sec

ρ 0 = 0.002377 slugs/ft3, standard sea level air density Ve = equivalent airspeed (ft/sec) CLα

= aircraft lift-curve slope per radian

S = wing reference area (ft2) W = gross weight (lbs)

8

1

F(PSD) = c

L

118

23.

π + 110

, µ

µ dimensionless (12)

c = wing mean geometric chord (ft) L = turbulence scale length, 2500 ft

2W µ =ρgcCLα

S , dimensionless (13)

ρ = air density (slugs/ft3) g = 32.17 ft/sec2

To determine the number of occurrences (N) for Uσ , calculate

60.4 o π c ρ N0( )refN = , dimensionless (14)=

N 0o 203 ρ

µ0( )

where c , ρ, ρ0, and µ are defined above. Then each Uσ peak is counted as N counts at that Uσ value. This number of counts is used to determine the number of counts per nautical mile (nm)

counts N or

interva in countin lnm

=

distance flown g (15)

Finally, the number of such counts is summed from the largest plus or minus value toward the smallest to produce the cumulative counts per nautical mile.

4.4 DATA REDUCTION CRITERIA.

To process the measured data into statistical flight loads format, specific data reduction criteria were established for each parameter. These criteria are discussed in this section.

4.4.1 Phases of Flight.

Each flight was divided into nine phases four ground phases (taxi out, takeoff roll, landing roll with and without thrust reverser, and taxi in), and five airborne phases (departure, climb, cruise, descent, and approach). Figure 3 shows these nine phases of a typical flight. The phases of flight were not defined by the airline but had to be determined from the data. Table 5 lists the conditions for determining the starting times for each phase. It should be noted that an airborne phase can occur several times per fli ght because it is determined by the rate of climb and the position of the flaps. When this occurs the flight loads data are combined and presented in a single flight phase. The UDRI software creates a fil e which chronologically lists the phases of flight and their corresponding starting times.

9

*Climb rate must be maintained for at least one minute before transition into another phase of flight takes place

FIGURE 3. DESCRIPTION OF PHASES OF FLIGHT

TABLE 5. PHASE OF FLIGHT STARTING CRITERIA

Phase of Flight Conditions at Start of Phase

Taxi Out Initial condition Takeoff Roll Acceleration > 4 kts/sec for a minimum of 12 seconds Departure Time at liftoff; flaps extended (squat switch off) Climb Flaps retracted; rate of climb ≥ 250 ft/min. for at least 1 minute

Cruise Flaps retracted; rate of climb ≤ 250 ft/min. for at least 1 minute Descent Flaps retracted; rate of descent ≤ -250 ft/min. for at least 1minute Approach Flaps extended; rate of descent < 250 ft/min. for at least 1 minute Landing Roll Touchdown; (squat switch on) Taxi In Magnetic heading change greater than 13.5 degrees after touchdown or

deviation from runway centerline greater than 100 feet

The criteria for the start of the takeoff roll have been redefined from those used in reference 3. In reference 3, the start of takeoff roll was defined as the time when the calibrated airspeed exceeded 50 knots and the longitudinal acceleration exceeded 0.15 g. It was found that in most cases when these criteria were met, the airplane had already been accelerating for 6 to 8 seconds and the initial portion of the takeoff roll was lost. The present criteria better defines the initial start of takeoff roll. When the acceleration remains above 4 knots per second for a minimum of 12 seconds, the takeoff roll phase begins.

The criteria for the start of taxi in has also been redefined from the criteria used in reference 3. In reference 3 the start of taxi in was defined as the time when thrust reversers were stowed after initial deployment on landing. This definition did not account for cases when the thrust reversers are not deployed during the landing roll or the thrust reversers are stowed before or after the airplane turns off the active runway. In the new criteria, the start of taxi in has been redefined as the time when the aircraft turns off the active runway. The primary method for detecting turnoff is to monitor magnetic heading change for a change greater than 13.5 degrees from the landing

10

magnetic heading. The time when the heading starts to change in the turnoff direction is then identified as the start of the turn or the beginning of the taxi in phase. This method can fail to detect a shallow turnoff onto a parallel taxiway. In such cases a substitute criteria that identifies a lateral deviation greater than 100 feet from the landing centerline is used to detect the turnoff point.

The criteria for determining the pitch angle at takeoff has been changed from that used in reference 3. In reference 3 the pitch angle at takeoff was defined as the maximum pitch angle occurring between 5 seconds before and 10 seconds after the squat switch moved from the closed to the open position. Using this time increment for selection of the pitch angle at takeoff results in pitch angles at the instant of takeoff that would cause the aircraft aft fuselage to strike the ground. For this report the pitch angle is defined as the angle occurring just prior to the squat switch change.

4.4.2 Flight Distance.

The flight distance can be obtained either by determining the stage length of the flight or by integrating the range with respect to changes in aircraft velocity as a function of time.

The stage length is defined as the distance from departure airport to destination airport and is determined as the great circle distance in nautical miles between the point of liftoff (departure) and the point of touchdown (destination). Appendix B describes the calculation of great circle distance. The time histories of longitude and latitude are matched against the UDRI generated phase of fli ght file to determine the geographical location of the aircraft at the point of liftoff and the point of touchdown.

The integrated flight distance D is obtained by the numerical integration from the time at liftoff (t0) to the time of touchdown (tn), and V is the average velocity during Δ t.

tn

D = ∑ Δ t ⋅ V (16) t0

4.4.3 Sign Convention.

Acceleration data are recorded in three directions: normal (z), lateral (y), and longitudinal (x). As shown in figure 4, the positive z direction is up; the positive y direction is airplane starboard; and the positive x direction is forward.

11

z

Up

Starboard

Parallel to Fuselage Reference Line

x

y

Forward

FIGURE 4. SIGN CONVENTION FOR AIRPLANE ACCELERATIONS

4.4.4 Peak-Valley Selection.

The peak-between-means method presented in reference 2 was used to select the peaks and valleys in the acceleration data. This method is consistent with past practices and pertains to all accelerations (nx, ny, Δ nz, Δ nzman

, Δ nzgust ). Figure 5 depicts an example of the peak-between-mean

criteria. This method counts upward events as positive and downward events as negative. Only one peak or one valley is counted between two successive crossings of the mean. A threshold zone is used in the data reduction to ignore irrelevant loads variations around the mean. For the normal accelerations Δ nz, Δ nzgust

, and Δ nzman , the threshold zone is ± 0.05 g; for lateral

acceleration ny, the threshold zone is ± 0.005 g; and for longitudinal accelerations nx, the threshold zone is ± 0.0025 g.

Deadband

Threshold Zone

}√

Mean Crossing ! Classified Peak

ο Classified Valley ⊕

FIGURE 5. THE PEAK-BETWEEN-MEANS CLASSIFICATION CRITERIA

12

13

A peak is generated only when the acceleration data cross into or through the deadband. Twosituations must be considered: the position of the current acceleration value relative to thedeadband and the position of the previous acceleration value relative to the deadband. In thepeak-between-means counting algorithm, the previous acceleration value is that value in aconsecutive set of values all of which lie either above the deadband or below the deadband. Theprevious value is established as a peak when the current value has crossed into or through thedeadband. Figures 6a and 6b demonstrate the concept of current and previous accelerationvalues. In figure 6a the current acceleration value passes into the deadband, whereas in figure 6bthe current value passes through the deadband.

FIGURE 6a. URRENT ACCELERATIONVAL UE PASSES INTO DEADBAND

FIGURE 6b. URRENT ACCELERATION VALUEPASSES THROUGH DEADBAND

Italicized text in table 6 summarizes the action(s) taken when the various possibilities occur.Note that when a previous acceleration value is retained as a potential peak, its coincident time isalso retained.

4.4.5 uver and Gust Load Factors.

The recorded normal acceleration (nz) values included the 1 g fli ght condition. conditionwas removed from each nz reading which was then recorded as Δnz. In order to avoid theinclusion of peaks and valleys associated with nonsignificant small load variations, a thresholdzone of Δnz = ±0.05 g was established. gorithm was then developed to extract theacceleration peaks and valleys.

For each fl ight, the maximum and minimum total accelerations were determined from just afterliftoff to just before touchdown. For the five in-flight phases, the Δnz cumulative occurrenceswere determined as cumulative counts per nautical mile and cumulative counts per 1000 hoursusing the peak-between-means counting method of reference 2 explained in section 4.4.4.

The incremental acceleration measured at the center of gravity (c.g.) of the aircraft may be theresult of either maneuvers or gusts or a combination of both. In order to derive gust statistics, themaneuver induced acceleration is separated from the total acceleration history. Most maneuverinduced loads are associated with turning maneuvers.

C C

Separation of Mane

The 1 g

An al

Δ

TABLE 6. PEAK CLASSIFICATION CRITERIA

Previous Acceleration Value Relative to

Deadband Current Acceleration Value Relative to Deadband

Below Within Above

Above Previous value is potential positive peak

Current acceleration passes through deadband. Previous value classified as a positive peak. Current value retained as a potential negative peak.

Current acceleration passes into deadband. Previous value classified as a positive peak. Acceleration value flagged as being in deadband.

Current acceleration is on same side of deadband as previous. If current > previous value, retain current value as potential positive peak and release previous.

Within At start of processing, or a peak was established but current acceleration value has not since gone outside of deadband

Current acceleration passes downward out of deadband. Current value is retained as a potential negative peak.

No Action Required

Current acceleration passes upward out of deadband. Current value retained as potential positive peak.

Below Previous value is potential negative peak

Current acceleration is on same side of deadband as previous. If current value < previous value, retain current value as potential negative peak and release previous value.

Current acceleration passes into deadband. Previous value is established as a negative peak. Acceleration value flagged as being in deadband.

Current acceleration passes through deadband. Previous value is classified as a negative peak. Current value retained as potential positive peak.

The increment due to a turning maneuver (Δ m) is determined using the bank angle method discussed in reference 2 to calculate the maneuver acceleration Δ nzman

as

Δ nzman = ( sec ϕ -1) (17)

where ϕ is the bank angle. The remaining peaks and valleys are assumed to be gust induced, where gust normal acceleration ( Δ nzgust

) is calculated as

Δ nzgust =Δ nz − nzman

(18)

This approach does not separate the pitching maneuvers induced by pilot control inputs. In reference 2, J.B. de Jonge suggests that accelerations resulting from pitch maneuvers induced by pilot input to counteract turbulence can be considered as part of the aircraft system response to the turbulence. Accelerations that are induced by the pitch maneuver at the specific points of rotation and flare during takeoff and climb and approach and touchdown have not been removed during this initial data reduction effort. Since turbulence is a more dominant loading input on commercial aircraft than maneuvers, correcting for pitch maneuvers at a later time will not substantiall y alter the statistics presented herein.

Once calculated, the measurements of Δ nz, Δ nzgust , and Δ nzman

are maintained as three unique data

streams. The Δ nzgust and Δ nzman

data are plotted as cumulative occurrences of a given

acceleration fraction per nautical mile and per 1000 flight hours. Separate plots are provided for each phase of flight and all phases combined. The Δ nz fraction is the recorded incremental

14

normal load factor (airplane limit load factor minus 1.0 g). As a result of the threshold zone, only accelerations greater than ± 0.05 g (measured from a 1.0 g base) are counted for data presentation.

4.4.6 Flap Detents.

When flaps are extended, the effective deflection is considered to be that of the applicable detent, as indicated in table 7. The flap deflection ranges and placard speeds reflect the flap design and cockpit placards.

TABLE 7. FLAP DETENTS (B-737-400)

Flap Detent

Minimum Flap Setting

Maximum Flap Setting

Design Placard Speed (KIAS)

Cockpit Placard Speed (KIAS)

1 > 0 < 0.5 250 250 5 > 0.5 < 5 250 250 10 > 5 < 10 218 215 15 > 10 < 15 213 205 25 > 15 < 25 206 190 30 > 25 < 30 199 185 40 > 30 < 40 162 162 45 >40 162 162

5. DATA PRESENTATION.

Table 8 lists the statistical data presentation formats for which data was processed and included in appendix A of this report. Similar statistical loads data, but of a reduced scope and based on fewer flights for a single aircraft, were previously presented in reference 3. To facilitate comparisons of the present data formats with this earlier data, the data formats available in reference 3 are identified by an asterisk in the listings of table 8.

Figures A-1 through A-83 present the processed data. It will be noted that the data presented in these figures are not always based on an identical number of fli ghts. During data reduction it was found that the acceleration measurements in certain flights exhibited random errors and were unreliable. When this occurred, those fli ghts were eliminated from the statistical data for any parameters associated, directly or indirectly, with the unreliable acceleration measurements. As a result, not all figures are based on data from identical numbers of flights, hours, or nautical miles.

5.1 AIRCRAFT OPERATIONAL USAGE DATA.

The aircraft usage data include fli ght profile statistics such as weights, altitudes, speeds, and flight distance information. This information is useful in the derivation of typical flight profiles and in defining ground-air-ground cycles for structural durability, damage tolerance analyses, future design criteria, and for use in the analysis of airline operating economics. Aircraft usage data are presented in figures A-1 through A-12.

15

TABLE 8. STATISTICAL DATA FORMATS

Data Description Figure AIRCRAFT USAGE DATA

WEIGHT DATA Cumulative Probability of Takeoff Gross Weight A-1 Cumulative Probability of Takeoff Fuel Weight A-2 Cumulative Probability of Landing Gross Weight A-3 Correlation of Takeoff Fuel Weight and Flight Distance, Percent of Flights A-4 Correlation of Takeoff Gross Weight and Flight Distance, Percent of Flights A-5 Correlation of Gross Weight at Li ftoff and Touchdown, Percent of Flights * A-6 ALTITUDE DATA Correlation of Maximum Alti tude and Flight Distance, Percent of Flights A-7 Percent of Total Distance in Alti tude Bands A-8 Coincident Altitude at Maximum Mach Number, Cruise Phase A-9a Coincident Altitude at Maximum Equivalent Airspeed, Cruise Phase A-9b Coincident Altitude at Maximum Mach Number, All Flight Phases A-10a Coincident Altitude at Maximum Equivalent Airspeed, All Flight Phases A-10b FLIGHT DISTANCES Cumulative Probability of Flight Distances A-11 AUTOPILOT OPERATION * Cumulative Probability of Percent of Flight Time on Autopilot A-12

GROUND LOADS DATA LATERAL LOAD FACTOR, ny

Cumulative Frequency of Maximum Side Load Factor During Ground Turns A-13 LONGITUDINAL LOAD FACTOR, nx

Cumulative Frequency of Longitudinal Load Factor During Ground Taxi A-14 Cumulative Frequency of Longitudinal Load Factor During Landing Roll A-15 Cumulative Probability of Maximum Longitudinal Load Factor During Takeoff A-16 Cumulative Probability of Minimum Longitudinal Load Factor During Landing A-17 VERTICAL LOAD FACTOR, nz

Cumulative Frequency of Incremental Vertical Load Factor During Taxi Operations A-18 Cumulative Frequency of Incremental Vertical Load Factor During Takeoff Roll A-19 Cumulative Frequency of Incremental Vertical Load Factor During Landing Roll A-20 Cumulative Probability of Minimum and Maximum Incremental Vertical Load Factor at Touchdown and Spoiler Deployment *

A-21

Coincident Incremental Vertical Load Factor and Touchdown Gross Weight A-22 GROUND SPEED DATA Cumulative Probability of Ground Speed During Taxi A-23 Cumulative Probability of Airspeed at Liftoff and Touchdown * A-24 FLARE DATA Cumulative Probability of Airspeed at Flare A-25 PITCH/ROTATION DATA Cumulative Probability of Pitch Angle at Liftoff and Touchdown * A-26 Cumulative Probability of Maximum Pitch Rate at Takeoff Rotation * A-27 Cumulative Probability of Pitch Angle at Touchdown Peak Vertical Load Factor * A-28

*Denotes data formats from reference 3.

16

TABLE 8. STATISTICAL DATA FORMATS (Continued)

Data Description Figure FLIGHT LOADS DATA

GUST LOADS DATA Cumulative Occurrences of Vertical Gust Load Factor per 1000 Hours by Flight Phase A-29 Cumulative Occurrences of Incremental Vertical Gust Load Factor per 1000 Hours, Combined Flight Phases

A-30

Cumulative Occurrences of Vertical Gust Load Factor per Nautical Mile by Flight Phase A-31 Cumulative Occurrences of Incremental Vertical Gust Load Factor per Nautical Mile, Combined Flight Phases

A-32

Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, < 500 Feet A-33 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 500-1,500 Feet A-34 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 1,500-4,500 Feet A-35 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 4,500-9,500 Feet A-36 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 9,500-19,500 Feet A-37 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 19,500-29,500 Feet A-38 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, 29,500-39,500 Feet A-39 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, Flaps Extended A-40 Cumulative Occurrences of Derived Gust Velocity per Nautical Mile, Flaps Retracted A-41 Cumulative Occurrences of Continuous Gust Intensity per Nautical Mile, Flaps Extended A-42 Cumulative Occurrences of Continuous Gust Intensity per Nautical Mile, Flaps Retracted A-43 MANEUVER LOADS DATA Cumulative Occurrences of Incremental Maneuver Load Factor per 1000 Hours During Departure by Altitude

A-44

Cumulative Occurrences of Incremental Maneuver Load Factor per 1000 Hours During Climb by Altitude

A-45

Cumulative Occurrences of Incremental Maneuver Load Factor per 1000 Hours During Cruise by Altitude

A-46

Cumulative Occurrences of Maneuver Load Factor per 1000 Hours During Descent by Altitude A-47 Cumulative Occurrences of Maneuver Load Factor per 1000 Hours During Approach by Altitude A-48 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Departure by Altit ude A-49 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Climb by Altitude A-50 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Cruise by Altitude A-51 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Descent by Altitude A-52 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile During Approach by Alti tude A-53 Cumulative Occurrences of Maneuver Load Factor per 1000 Hours by Flight Phase A-54 Cumulative Occurrences of Maneuver Load Factor per 1000 Hours, Combined Flight Phases A-55 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile by Flight Phase A-56 Cumulative Occurrences of Maneuver Load Factor per Nautical Mile, Combined Flight Phases A-57 COMBINED MANEUVER AND GUST LOADS DATA * Cumulative Occurrences of Combined Maneuver and Gust Vertical Load Factor per 1000 Hours by Flight Phase

A-58

Cumulative Occurrences of Vertical Load Factor per 1000 Hours, Combined Flight Phases A-59 Cumulative Occurrences of Vertical Load Factor per Nautical Mile by Flight Phase A-60 Cumulative Occurrences of Vertical Load Factor per Nautical Mile, Combined Flight Phases A-61 Cumulative Occurrences of Lateral Load Factor per 1000 Hours, Combined Flight Phases A-62 Coincident Maneuvers Load Factor and Speed Versus V-n Diagram for Flaps Retracted A-63 Coincident Maneuvers Load Factor and Speed Versus V-n Diagram for Flaps Extended A-64 Coincident Gust Load Factor and Speed Versus V-n Diagram for Flaps Retracted A-65 Coincident Gust Load Factor and Speed Versus V-n Diagram for Flaps Extended A-66

*Denotes data formats from reference 3.

17

TABLE 8. STATISTICAL DATA FORMATS (Continued)

Data Description Figure MISCELLANEOUS OPERATIONAL DATA

FLAP USAGE DATA Cumulative Probability of Maximum Airspeed in Flap Detent During Departure A-67 Cumulative Probability of Maximum Airspeed in Flap Detent During Approach A-68 Percent of Time in Flap Detent During Departure A-69 Percent of Time in Flap Detent During Approach A-70 Cumulative Probability of Maximum Dynamic Pressure in Flap Detent During Departure A-71 Cumulative Probability of Maximum Dynamic Pressure in Flap Detent During Approach A-72 SPEED BRAKE/FLIGHT SPOILER DATA Cumulative Probability of Maximum Speed During Speed Brake Deployment A-73 Cumulative Frequency of Speed at Speed Brake Deployment A-74 Cumulative Frequency of Altitude at Speed Brake Deployment A-75 Cumulative Probability of Maximum Deployment Angle During Speed Brake Deployment, Flaps Retracted

A-76

THRUST REVERSER DATA Cumulative Probability of Time With Thrust Reversers Deployed A-77 Cumulative Probability of Speed at Thrust Reverser Deployment and Stowage A-78

LANDING GEAR EXTENSION/RETRACTION DATA Cumulative Probability of Time With Landing Gear Extended After Liftoff A-79 Cumulative Probability of Time With Landing Gear Extended Prior to Touchdown A-80 Cumulative Probability of Maximum Airspeed With Gear Extended A-81

PROPULSION SYSTEM DATA Cumulative Probability of Percent of N1 at Takeoff A-82 Cumulative Probability of Percent of N1 A-83

*Denotes data formats from reference 3.

5.1.1 Weight Data.

Statistical data on operational takeoff gross weights, landing gross weights, and fuel weights are presented in this section. These weights are also correlated to flight distance. The cumulative probabilities of takeoff gross weight, takeoff fuel weight, and landing weight are presented in figures A-1 through A-3 respectively. The correlation between fuel weight at takeoff and the flight distance is presented in figure A-4. A similar correlation for takeoff gross weight and flight distance is shown in figure A-5. The fli ght distances in figures A-4 and A-5 are based on the great circle distance between departure and arrival points. It is interesting to note that the small difference in the number of fli ghts between figures A-4 and A-5 has an insignificant impact on the flight distance distribution as indicated by a comparison of the numbers in the right end columns of these figures. Figure A-6 provides the correlation between the takeoff gross weight and the landing gross weight. The correlation shows that for most flights with light takeoff weights (less than 100,000 pounds) the landing weight is within 10,000 pounds of the takeoff weight. For the medium takeoff weights from 100,000-130,000 pounds the landing weights are from 10,000-20,000 pounds below takeoff weight. For the heavy weight takeoffs from 130,000-150,000 pounds the landing weights are from 20,000-30,000 pounds below the takeoff weight.

18

5.1.2 Altitude Data.

Measured operational altitudes and their correlation to flight distance and maximum speed are presented. Figure A-7 shows the correlation between the maximum altitude attained in flight and the flight distance flown in percent of flights. The data show that for short flights of less than 250 nautical miles, the maximum altitude is generally below 30,000 feet with the most flights occurring from 20,000-25,000 feet. For fli ghts from 250-500 nautical miles the altitude may range from 25,000 to 40,000 feet, while for fli ghts above 500 nautical miles the maximum altitude can be considered above 30,000 feet. Figure A-8 presents the percent of total flight distance spent in various altitude bands as a function of flight distance. The fli ght distances in figure A-7 reflect the stage lengths, whereas the flight distances in figure A-8 are based on the numerical integration approach mentioned in paragraph 4.4.2. The combined information in figures A-7 and A-8 provide a comprehensive picture of the flight profile distribution. Figures A-9a and A-9b show the coincident altitude at the maximum Mach number and the maximum equivalent airspeed attained in the cruise phase of the fli ghts respectively. Figures A-10a and A-10b show the maximum Mach number or the maximum equivalent airspeed with respect to the design cruise limit regardless of flight phase. In other words, the speed that most closely approached the speed limit in a flight was identified as the maximum speed. As an example, in one flight the maximum speed with respect to the limit might have been attained in the climb phase, while in another flight the maximum speed with respect to the limit speed might have occurred in the cruise phase. The data in figures A-10a and A-10b are fairly evenly distributed between the climb, cruise, and descent phases with only a single occurrence in the departure and approach phases. The design speed limits are also shown in the figures. It should be noted that maximum Mach number and maximum equivalent airspeed do not necessarily occur simultaneously.

5.1.3 Flight Distance Data.

Flight distance statistics useful in the generation of flight profiles were derived and are presented here. The cumulative probability of fli ght distances flown is presented in figure A-11. The great circle distance reflects the ground distance between two points as obtained from the great circle distance calculation, but does not necessaril y reflect the actual distance flown. Deviation from direct fli ght between departure and arrival points resulting from traffi c control requirements will increase the actual distance flown by some unknown amount. To a much lesser extent, the climb and descent distances are slightly larger than the level fl ight distance. Head or tail winds also are unknown contributors. The integrated distance accounts for such variables. The figure provides a graphical presentation of the differences in flight distance obtained by the two approaches.

5.1.4 Autopilot Usage.

Autopilot usage is determined by the operational procedures employed. Figure A-12 shows the cumulative probabilit y of percent fli ght time flown on autopilot. Comparison with the autopilot data presented in reference 3 shows that autopilot usage has increased significantly.

19

5.2 GROUND LOADS DATA.

The ground loads data include frequency and probability information on vertical, lateral, and longitudinal accelerations, speeds, and pitch rotation associated with takeoff, landing, and ground operations. These data are of primary importance to landing gear and landing gear backup structure and to a lesser extent to the wing, fuselage, and empennage.

5.2.1 Lateral Load Factor Data.

Lateral load factor statistics resulting from ground turning during taxi were derived and are presented. Figure A-13 shows the cumulative frequency of maximum side load factor during ground turns. The information is presented for preflight and postflight taxi, as well as, left and right turns. The turning load factors during taxi in are shown to be more severe than those experienced during turning while taxiing out. This is likely the result of higher taxi in speed as shown in figure A-23. There is no significant difference between the number of left and right turns.

5.2.2 Longitudinal Load Factor Data.

Longitudinal load factor statistics were derived for all phases of ground operation, including preflight and postflight taxi, and takeoff and landing roll. Figures A-14 and A-15 present the cumulative frequency of longitudinal load factor during ground operations. Figure A-14 shows the data for pre- and postflight taxi. The higher number of occurrences of negative longitudinal load factor less than –0.15 g during the taxi in phase are possibly due to braking action occurring at the higher taxi in speeds. Figure A-15 shows the landing rollout with and without thrust reverser deployment. Figures A-16 and A-17 present the cumulative probabilit y of the maximum longitudinal load factor measured during the takeoff and landing rolls respectively.

5.2.3 Vertical Load Factor Data.

Vertical load factor statistics during all phases of ground operation with and without thrust reverser were derived and are presented. Figure A-18 presents the cumulative frequency of incremental vertical load factor during preflight and postflight taxi. Figure A-19 presents the cumulative frequency of incremental vertical load factor during the takeoff roll, while Figure A-20 presents the cumulative frequency of incremental vertical load factor during the landing roll for operation with and without thrust reverser. As can be seen there is little difference in the frequency of vertical load factor occurrences resulting from taxi, takeoff roll, and landing roll except for positive occurrences during landing without thrust reverser. It is noteworthy (see figure A-15) that there is also increased longitudinal load factor activit y during landing without thrust reversers. Figure A-21 presents the cumulative probability of the minimum and maximum incremental vertical load factors associated with touchdown and ground spoiler deployment. As can be seen the minimum load factors measured at spoiler deployment remain positive. Figure A-22 shows the coincident incremental vertical load factor and gross weight at touchdown for all flig hts.

20

5.2.4 Ground Speed Data.

The cumulative probabilities of ground speed for taxi in and taxi out operations are presented in figure A-23. The taxi in speeds are seen to be considerably higher than the taxi out speeds. There can be several reasons for this difference. First, the airplane may still be moving at a fairl y high speed shortly after turning off the active runway. Departure from the active runway has been used as the criterion for start of taxi in. Second, movement of inbound traffic to the terminal after landing is generally accomplished faster than similar movement from the terminal to the takeoff position. Figure A-24 shows the cumulative probabilities of airspeed at liftoff and touchdown rotation. The liftoff speeds are approximately 20 knots higher than the touchdown speeds. The figure indicates that a considerable number of touchdowns are performed at speeds well above published stall speeds.

5.2.5 Flare Data.

Figure A-25 presents the cumulative probabilit y of airspeed at flare. Since the actual instant of flare is diffi cult to determine with any great accuracy, the start of flare was assumed to occur 3 seconds prior to main gear squat switch closure.

5.2.6 Pitch/Rotation Data.

The cumulative probabilit y of maximum pitch angle at takeoff and landing is presented in figure A-26. The pitch angles for takeoff presented in this figure are considerably lower than those previously reported in reference 3. It has been determined that the time increment previously used for selecting the pitch angle at takeoff was too long, resulting in pitch angles at the instant of takeoff that would have resulted in the aircraft aft fuselage striking the ground. This increment was reduced for the present data reduction effort as discussed in section 4.4.1. Figure A-27 presents the cumulative probabilit y of maximum takeoff pitch rate at takeoff rotation. Figure A-28 presents the cumulative probability of pitch angle that occurs at touchdown peak vertical load factor.

5.3 FLIGHT LOADS DATA.

The flight loads data include the statistical data that describe the gust and maneuver environment. The gust environment is presented in the form of cumulative occurrences of derived gust velocity, continuous gust intensity, and vertical load factor. The derived gust velocity and continuous gust intensity are computed values as described in section 4.3. Since the 1950’s, it has been common practice to present flight loads data as cumulative occurrences. Data that were previously recorded on the B-737 are reported in references 4 and 5 as cumulative occurrences per 1000 hours. To compare to data from different references, the normal acceleration data are plotted two ways, as cumulative occurrences per 1000 hours and as cumulative occurrences per nautical mile.

5.3.1 Gust Loads Data.

The gust data are presented in the form of derived gust velocity Ude and continuous gust intensities Uσ . Figure A-29 presents the cumulative occurrences of incremental vertical gust

21

load factor per 1000 hours. The data are presented by phase of fli ght. Figure A-30 shows cumulative occurrences of incremental vertical gust load factor for the total combined airborne phases per 1000 hours. Figure A-31 presents the cumulative occurrences of incremental vertical gust load factor per nautical mile by phase of fli ght, and figure A-32 shows the cumulative occurrences of incremental vertical gust load factor for the total combined airborne phases per nautical mile. In figures A-33 through A-39 the derived gust velocity Ude is plotted as cumulative counts per nautical mile for altitudes from sea level to 39,500 feet. Figures A-40 and A-41 present the derived gust velocity Ude as cumulative counts per nautical mile with flaps extended and retracted respectively.

5.3.2 Maneuver Loads Data.

The technique used to identify maneuvers assumes that maneuvers are associated primarily with turning conditions and that the impact of pitch maneuvers is insignificant and can be ignored. As a result, maneuvers resulting from push down or pull up maneuvers are ignored and only positive maneuver load factors resulting from banked turns are identified.

Figures A-44 through A-48 present the cumulative occurrences of maneuver load factor per 1000 hours by altitude for each of the airborne fli ght phases, i.e., departure, climb, cruise, descent, and approach. Figures A-49 through A-53 present the cumulative occurrences of maneuver load factor by altitude per nautical mile in the airborne phases of fli ght. Figure A-54 presents the total cumulative occurrences of incremental maneuver load factor per 1000 hours for each phase of flight, regardless of altitude. Figure A-55 presents the total cumulative occurrences of incremental maneuver load factor per 1000 hours for all flight phases combined. Figure A-56 presents the total cumulative occurrences of incremental maneuver load factor per nautical mile for each phase of fli ght regardless of altitude. Figure A-57 presents the total cumulative occurrences of incremental maneuver load factor per nautical mile for all flight phases combined. The maneuver data presented in this report extend beyond load factor magnitudes available in reference 3. However, at identical load factor levels, the data trends between this report and reference 3 are quite similar.

5.3.3 Combined Maneuver and Gust Loads Data.

For the data presented in this section, the maneuver and gust load factors were not separated, but the total load factor occurrences regardless of the cause were used in the derivation of the figures. Figure A-58 shows the cumulative occurrences of total combined maneuver and gust normal load factor per 1000 hours by phases of flight, and figure A-59 shows the occurrences for all phases combined. Figures A-60 and A-61 show the data of figures A-58 and A-59 as occurrences per nautical mile.

Federal Aviation Regulation (FAR) 25.333 requires that airplane structural operating limitations be established at each combination of airspeed and load factor on and within the boundaries of maneuvering and gust load envelopes (V-n diagrams). For purposes of displaying the coincident maneuver or gust accelerations, four representative V-n diagrams were developed from the FAR requirements.

22

The required limit load factors for maneuvers are specified in FAR 25.337. The positive limit maneuvering load factor (n) may not be less than 2.5, and the negative limit maneuvering load factor may not be less than -1.0 at speeds up to VC , varying linearly with speed to zero at VD. FAR 25.345 specifies that the positive limit maneuver load factor is 2.0 g when the flaps are extended. The stall curve on the left side of the envelopes is determined by the maximum lift coeffi cient. The curve was estimated by using the 1 g stall speed to estimate CLmax

.

The required limit load factors for gusts result from gust velocities as specified in FAR 25.341. The FAR specifies positive (up) and negative (down) air gust design requirements for three different aircraft design speeds: maximum gust intensity (VB), cruising speed (VC), and dive speed (VD). Between sea level and 20,000 feet, the gust requirement is constant, varying linearly to the value given for 50,000 feet. FAR 25.345 sets a requirement of positive, negative, and head-on for 25 fps gusts when flaps are extended. These gust design requirements are shown in table 9.

TABLE 9. FAR REQUIREMENTS FOR DERIVED DISCRETE GUST VELOCITIES

Aircraft Design Speed

Gust Velocity 0-20,000 Feet Altitude

50,000 Feet Altitude

VB 66 fps 38 fps VC 50 fps 25 fps VD 25 fps 12.5 fps

Flaps Extended 25 fps

Sufficient data to generate V-n diagrams for all weight and altitude conditions were not available. Therefore, sea level data were used to develop the representative diagrams, and all of the recorded maneuvers and gusts were plotted on these. A weight of 90,000 lbs., the lowest recorded weight, was used for the calculations required in developing these diagrams.

Figure A-63 through A-66 shows the V-n diagrams for maneuver and for gust with flaps retracted and extended. Coincident acceleration and speed measurements are also plotted on the V-n diagrams. As can be seen in figure A-66, a large number of gust accelerations occurred outside the gust V-n diagram for the flaps extended case.

5.4 MISCELLANEOUS OPERATIONAL DATA.

The miscellaneous operational data includes statistical usage information for flaps, speed brake/spoilers, thrust reversers, and landing gear operations. Although aileron and rudder deflection information was available it was not processed because it was deemed that the slow sampling rates prevented the reduction of reliable statistical usage information for these components.

23

5.4.1 Flap Usage Data.

Flap usage statistics of value in the design of flap structure, backup structure, and other flap components were reduced from the measured data. Figure A-67 presents the cumulative probability of maximum airspeed encountered in various flap detents during the departure phase of the flights. The flap detents are defined in table 7. The single points for detents 40 and 45 at 160 knots indicate a single occurrence of these settings during departure. Figure A-68 presents similar data for the approach phase of the fli ghts. Figures A-69 and A-70 present the percent of time spent in various flap detents during the departure and approach phases of flight, respectively. As shown in figure A-69, flap detent 5 was the detent used in almost all cases during departure. Previous data presented in reference 6 showed that detent 1 was used approximately one-third of the total time. Discussion with the airline confirmed that a change in flap operating procedure for departure had occurred between the two reporting periods. Comparison of the data in figure A-70 with similar data in reference 5 shows that although changes in flap usage for approach had occurred, these changes were not as dramatic as those seen for the departure phase. Figures A-71 and A-72 show the cumulative probabilit y of maximum dynamic pressure encountered while in different flap detents for the departure and approach phases respectively. The single points for detents 40 and 45 in figure A-71 indicate a single occurrence of these settings during departure.

5.4.2 Speed Brake/Spoiler Usage Data.

Information on speed brake operations during fli ght was determined to be of primary interest to various users of the data. Therefore, statistics on speed brake usage as a function of speed, altitude, and deflection angle were derived from the measured data. To be counted as a deployment cycle the speed brake had to deflect more than 7 degrees for a period of 3 seconds. Data on spoiler operations occurring during the landing roll are available, but were not reduced into statistical format. Figure A-73 presents the cumulative occurrences of maximum speed encountered while the speed brakes were deployed, while figure A-74 presents the cumulative occurrences of speed at the moment of speed brake deployment. Figure A-75 presents the cumulative occurrences of altitude at the moment of speed brake deployment. Figure A-76 presents the cumulative probabilit y of maximum deployment angle reached during the time that the speed brakes were deployed for the flaps retracted configuration. As can be seen in figures A-73 through A-76 speed brake cycles occur on average less than once per flight. Speed brake cycles occurred but were not counted for the conditions of flaps deflected in various detents.

5.4.3 Thrust Reverser Data.

Cumulative probabilities of duration and speed associated with thrust reverser operations were derived from the measured data. Figure A-77 presents the cumulative probabilit y of total time that thrust reversers are deployed. Figure A-78 presents the cumulative probabilit y of the speed at the time when the thrust reversers were deployed or stowed. Although normall y the thrust reversers are deployed and stowed a single time for each landing, the measured data showed two cycles of thrust reverser operation on a few occasions. This accounts for the rare occurrence of thrust reverser deployment at speeds as low as 45 knots in figure A-78. The data processing did not evaluate the engine power lever angles existing at these specific low-speed thrust reverser

24

deployments. However, at such low speeds, exhaust gas re-ingesting becomes a concern. Normally the engine manufacturer specifies a thrust reverser cutoff speed, typically about 50 knots, below which thrust reversers should not be used.

5.4.4 Landing Gear Extension/Retraction Data.

Landing gear operating statistics were reduced from the measured data. The information can be used to support design, evaluation, and monitoring of the landing gear and associated structure. Figure A-79 shows the cumulative probabilit y of total time with the landing gear extended after liftoff. Figure A-80 shows the cumulative probabilit y of time with the landing gear extended prior to touchdown. As is expected, the time with gear extended during approach is considerably longer than the time after liftoff when the pilot retracts the gear within seconds after liftoff. Figure A-81 presents the cumulative probabilit y of the maximum airspeed during the time that the gear is extended for both the departure and approach phases of flight.

5.5 PROPULSION SYSTEM DATA.

The cumulative probabilit y of engine fan speed N1 associated with thrust reverser operations was derived from the measured N1 engine parameter. Figure A-82 presents the cumulative probabilit y of engine fan speed N1 at takeoff, at thrust reverser deployment, and the maximum fan speed N1 encountered during the time that the thrust reverser is deployed.

6. CONCLUSIONS.

Incorporation of the additional data formats provides new and informative statistical information to the aircraft manufacturers, airlines, and the FAA.

Comparison of the gust load factor occurrence data of this report based on 13,916 hours with the same data based on 817.7 hours in reference 3 shows general agreement for incremental load factor levels to plus or minus 0.5 g. At higher load factors the new data shows reduced occurrence levels, indicating that the extrapolation of limited data samples may lead to erroneous results. An identical conclusion is drawn when comparing the maneuver load factor results. The FAA goal is to collect a minimum of recorded flight hours equal to one design life to provide a reliable database. It would seem prudent to continue the data gathering for some time, until a stable database is obtained.

The autopilot and flap usages presented in this report differ significantly from earlier usages presented in reference 3. This suggests that the operational procedures employed change over time. Changes in operational procedures would be expected to apply to all identical aircraft in the airline fleet. To track the impact of such changes a single representative aircraft should remain installed with a flight loads recorder throughout its life.

The data in figure A-66 shows that the measured gust load factors for the flaps extended configuration often occur outside the design V-n diagram. The data suggests that the present gust design requirements for the flaps extended configuration may need to be reviewed for adequacy. An assessment of the appropriateness of the continued use of Ude values specified in FAR 25.345 for high-lift devices appears to be justified. Derived gust velocity, Ude, values

25

obtained from this effort show deviation from the data presented in reference 6. In general, for altitudes below 1,500 feet the B-737–400 data show higher levels of occurrences for the upward gusts and fewer for the downward gusts than presented in reference 6. For the altitude range from 1,500-9,500 feet the occurrences from the B-737-400 compare very well with the reference 6 data. For levels above 9,500 feet the B-737-400 occurrences are below those predicted by reference 6. In as much as reference 6 represented a rather preliminary effort to define atmospheric turbulence in power spectral format, the B-737-400 data should also be compared to other study results to provide a more complete assessment of the B-737-400 data and its influence on future design requirements.

Furthermore, calculation of turbulence field parameters, P and b values, based on the B-737-400 data is considered desirable and should be included in future data reduction efforts. The resulting values should be compared with turbulence field parameters specified in reference 6 and Appendix G to Part 25 of the FAR.

The technique used in this report to separate gust and maneuver accelerations results in positive maneuver occurrences only. The most common method previously used to separate maneuver and gust accelerations has been the so called 2-second rule. From reviews of measured data and studies of aircraft response to elevator motion it was determined that for larger aircraft essentially all of the maneuver load factor peaks can be expected to be counted if a time between zero crossings greater than 2 seconds is used. Load factor peaks with zero crossings less than 2 seconds will mostly all be gusts. This approach resulted in the identification of both positive and negative maneuver occurrences. A cursory review of the B-737-400 acceleration data shows that pitching maneuvers resulting in both positive and negative accelerations do occur with some frequency and magnitude in the climb phase. Unfortunately these occurrences are counted as gusts. A study to evaluate the impact of different maneuver and gust separation criteria is very important and should be done before much is made of the differences in the gust frequencies noted and before turbulence field parameters are derived.

Statistical information on flight control surface activity is a valuable input to the design requirements for these surfaces and their associated components. Flight control surface deflections are recorded at two samples per second (2 sps) and can easily be reduced to provide the desired information. Unfortunately, there are doubts about the adequacy of the sampling rates to provide reliable results. For this reason the flight control surface deflection data were not processed. A study to determine the sampling rates as a function of control surface deflection rate necessary to provide acceptable statistical surface deflection information would be invaluable.

26

7. REFERENCES.

1. Crabill, Norman L., “FAA/NASA Prototype Flight Loads Program Systems Requirements, B737-400 Aircraft,” Eagle Aerospace Inc., Contract NAS1-19659, unpublished report, November 1994.

2. de Jonge, B., “Reduction of Incremental Load Factor Acceleration Data to Gust Statistics,” DOT/FAA/CT-94/57, August 1994.

3. “Flight Loads Data for a Boeing 737-400 in Commercial Operation,” Department of Transportation Report DOT/FAA/AR-95/21, April 1996.

4. “Data From Unusual Events Recording System in a Commercial 737 Aircraft,” Technology Incorporated Instruments and Controls Division, Dayton OH, Report No. FAA-RD-72-113, November 1972.

5. Clay, Larry E., DeLong, Robert C., and Rockafellow, Ronald I., “Airline Operational Data From Unusual Events Recording Systems in 707, 727, and 737 Aircraft,” Report No. FAA-RD-71-69, September 1971.

6. Press, Harry and Steiner, Roy, “An Approach to the Problem of Estimating Severe and Repeated Gust Loads for Missile Operations,” National Advisory Committee for Aeronautics Technical Note 4332, September 1958, Langley Aeronautical Laboratory, Langley Field, Va.

27/28

APPENDIX A DATA PRESENTATION

35

4025

30

15

205

10

Ta

keo

ff G

ros

s W

eig

ht

(10

00

Lb

)

Take

off

Fue

l Wei

ght

(10

00

Lb

)

FIG

UR

E A

-1. C

UM

UL

AT

IVE

PR

OB

AB

ILIT

Y O

F T

AK

EO

FF

F

IGU

RE

A-2

. CU

MU

LA

TIV

E P

RO

BA

BIL

ITY

OF

TA

KE

OF

F

GR

OSS

WE

IGH

T

FU

EL

WE

IGH

T

11

44

5 F

ligh

ts10

0

10-1

10-2

10-5

80

90

100

110

120

130

140

150

10-3

Cumulative Probability

11

39

8 F

ligh

ts10

0

10-1

10-2

10-3

10-4

Cumulative Probability

A-1

11

44

5 F

ligh

ts

Tak

eoff

Fue

l We

igh

t (1

000

Lb)

10

0

10-1

10-2

80

90

100

110

120

130

La

nd

ing

Gro

ss

We

igh

t (1

00

0 L

b)

FIG

UR

E A

-3. C

UM

UL

AT

IVE

PR

OB

AB

ILIT

Y O

F L

AN

DIN

G

FIG

UR

E A

-4. C

OR

RE

LAT

ION

OF

TA

KE

OF

F F

UE

L G

RO

SS W

EIG

HT

W

EIG

HT

AN

D F

LIG

HT

DIS

TA

NC

E, P

ER

CE

NT

OF

FLIG

HT

S

Tot

al

16.

689

35.

526

17.

781

18.

515

5.5

13

1.4

68

2.9

97

1.3

19

0.1

92

100

35-

40

0.0

09

0.1

92

0.0

35

0.0

61

0.3

23

0.4

46

0.1

66

1.2

32

30-

35

0.0

7

0.0

09

0.3

84

0.4

98

0.6

47

0.6

82

2.1

49

0.8

21

0.0

26

5.2

86

25-

30

0.0

79

0.1

4

1.1

45

3.0

93

2.6

65

0.6

29

0.5

07

0.0

52

8.3

09

20-

25

0.6

64

3.8

62

6.3

17

11.

691

2.0

8

0.0

96

0.0

17

24.

727

15-

20

5.6

18

19.

056

9.5

67

3.0

32

0.0

79

37.

353

10-

15

9.8

91

12.

46

0.3

58

22.

709

5-1

0

0.3

67

0.0

09

0.0

09

0.3

84

114

45

Flts

0-2

50

250

-50

0

500

-75

0

750

-10

00

100

0-1

25

0

125

0-1

50

0

150

0-1

75

0

175

0-2

00

0

200

0-2

25

0

Tot

al

Flight Distance (NM)

Cumulative Probability

A-2

Takeoff Gross Weight (1000 Lb)

Flig

ht D

ista

nce

(N

M)

11398 Flts 80-90 90-100 100-110 110-120 120-130 130-140 140-150 Total

0-250 0.14 2.343 6.413 5.782 2 16.678

250-500 0.044 2.676 9.203 13.397 10.177 0.035 35.533

500-750 0.132 1.904 5.027 9.589 1.105 0.009 17.766

750-1000 0.079 1.237 3.834 9.037 4.343 0.009 18.538

1000-1250 0.149 0.886 2.062 2.316 0.105 5.519

1250-1500 0.026 0.307 0.404 0.658 0.07 1.465

1500-1750 0.053 0.518 1.5 0.912 2.983

1750-2000 0.009 0.035 0.123 0.842 0.316 1.325

2000-2250 0.018 0.088 0.088 0.193

Total 0.184 5.229 18.942 29.321 33.927 10.888 1.509 100

FIGURE A-5. CORRELATION OF TAKEOFF GROSS WEIGHT AND FLIGHT DISTANCE, PERCENT OF FLIGHTS

Gross Weight at Liftoff (1000 Lb)

Gro

ss

We

ight

at T

ouc

hd

own

(1

000

Lb

)

Total140-150130-140120-130110-120100-11090-10080-9011398 Flts

1.5090.1321.1930.18480-90

17.1350.1141.93911.0464.03690-100

33.3130.0351.0444.83419.6357.765100-110

46.6491.439.11628.3567.747110-120

1.3950.0440.7280.623120-130

1001.50910.88833.92729.32118.9425.2290.184Total

FIGURE A-6. CORRELATION OF GROSS WEIGHT AT LIFTOFF AND TOUCHDOWN, PERCENT OF FLIGHTS

A-3

Maximum Altitude (1000 Feet)

Total35-4030-3525-3020-2515-2010-155-100-511723 Flts

16.7190.1360.3922.2699.0682.6021.6380.5630.0510-250

35.5288.24910.66314.9111.6890.017250-500

17.7348.4368.4620.7680.068500-750

18.5878.3179.7330.4780.06750-1000

5.5112.323.0620.0940.0341000-1250

1.450.7930.6310.0261250-1500

2.9691.4761.4670.0261500-1750

1.2970.3840.8870.0261750-2000

0.2050.0340.1712000-2250

10030.14635.46918.59610.9192.6191.6380.5630.051Total

Flig

htD

ista

nce

(NM

)

FIGURE A-7. CORRELATION OF MAXIMUM AL TITUDE AND FLIGHT DISTANCE, PERCENT OF FLIGHTS

Total Flight Distance (NM)

11723 Flts 0-250 250-500 500-750 750-1000 1000-1250 1250-1500 1500-1750 1750-2000 2000-2250 2250-2500

29,500-39,500 0.09 20.03 51.4 64.46 70.11 76.33 80.4 81.79 81.63 83.56

19,500-29,500 28.14 42.66 26.6 20.27 17.95 14.44 11.6 11.32 12.54 12.17

9,500-19,500 42.13 22.02 12.76 8.69 6.94 5.67 4.71 3.99 3.44 2.4

4,500-9,500 16.73 8.6 5.26 3.66 2.91 2.05 2.13 1.77 1.25 0.92

1,500-4,500 10.31 5.24 3.09 2.18 1.6 1.19 0.93 0.93 0.89 0.71

500-1,500 2.04 1.07 0.68 0.49 0.34 0.23 0.18 0.17 0.18 0.16

0-500 0.56 0.38 0.21 0.24 0.16 0.08 0.05 0.04 0.06 0.08

Total 100 100 100 100 100 100 100 100 100 100

Altit

ude

Ban

d (

Fee

t)

FIGURE A-8. PERCENT OF TOTAL DISTANCE IN ALTITUDE BANDS

A-4

FIG

UR

E A

-9a.

N

CID

EN

T A

LT

ITU

DE

AT

MA

XIM

UM

MA

CH

NU

MB

ER

, CR

UIS

E P

HA

SE

FIG

UR

E A

-9b.

N

CID

EN

T A

LT

ITU

DE

AT

MA

XIM

UM

EQ

UIV

AL

EN

T A

IRSP

EE

D, C

RU

ISE

PH

AS

E

0

5000

1000

0

1500

0

2000

0

2500

0

3000

0

3500

0

4000

0

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Coincident Pressure Altitude (Feet)

Mac

h N

umbe

r

Mcr

uise

0

5000

1000

0

1500

0

2000

0

2500

0

3000

0

3500

0

4000

0

200

250

300

350

Coincident Pressure Altitude (Feet)

Equi

vale

nt A

irspe

ed, V

e (

Kno

ts)

Vcr

uise

A-5

Equ

ival

ent A

irspe

ed, V

e (K

nots

)M

ach

Num

ber

CO

IC

OI

FIG

UR

E A

-10a

. N

CID

EN

T A

LT

ITU

DE

AT

MA

XIM

UM

MA

CH

NU

MB

ER

, AL

L F

LIG

HT

PH

AS

ES

FIG

UR

E A

-10b

. N

CID

EN

T A

LT

ITU

DE

AT

MA

XIM

UM

EQ

UIV

AL

EN

T A

IRSP

EE

D, A

LL F

LIG

HT

PH

AS

ES

0

5000

1000

0

1500

0

2000

0

2500

0

3000

0

3500

0

4000

0

0.3

0.4

0.5

0.6

0.7

0.8

0.9

Coincident Pressure Altitude (Feet)

Mac

h N

umbe

rMcr

uise

0

5000

1000

0

1500

0

2000

0

2500

0

3000

0

3500

0

4000

0

200

250

300

350

Coincident Pressure Altitude (Feet)

Equi

vale

nt A

irspe

ed, V

e (

Kno

ts)

Vcr

uise

A-6

Equ

ival

ent A

irspe

ed, V

e (K

nots

)M

ach

Num

ber

CO

IC

OI

1

1

0.9

0.9

0.8

0.8

0.7

0.7

0.6

0.6

0.5

0.5

0.4

0.4

0.3

0.3

0.2

0.2

0.1

0.1

00

0 50

0 10

00

1500

20

00

2500

0

20

40

60

80

Flig

ht D

ista

nce

(N

M)

Pe

rcen

t Tim

e A

utop

ilot E

ngag

ed

FIG

UR

E A

-11.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F FL

IGH

T

FIG

UR

E A

-12.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F P

ER

CE

NT

D

IST

AN

CE

S

OF

FLI

GH

T T

IME

ON

AU

TO

PIL

OT

Cumulative Probability

Gre

at C

ircle

Dis

tanc

e In

terg

rate

d D

ista

nce

11

721

Flig

hts

Cumulative Probability

A-7

100

105

104

104

103

103

102

102

101

101

100

100

10-1

Taxi

In

Taxi

Out

1

1723

Flig

hts

10

-1

10-2

1

0-2

-1

-0.5

0

0.5

-0

.4

-0.3

-0

.2

-0.1

0

0.1

0.2

0.3

0.4

Tax

i In

Ta

xi O

ut

1127

1 F

light

s

Sid

e L

oad

Fac

tor,

ny

(g

) Lo

ngitu

din

alL

oad

Fact

or, n

(g

) x

FIG

UR

E A

-13.

CU

MU

LAT

IVE

FR

EQ

UE

NC

Y O

F M

AXI

MU

M S

IDE

F

IGU

RE

A-1

4. C

UM

ULA

TIV

E F

RE

QU

EN

CY

OF

LO

AD

FA

CT

OR

DU

RIN

G G

RO

UN

D T

UR

NS

LO

NG

ITU

DIN

AL

LOA

D F

AC

TO

R D

UR

ING

GR

OU

ND

TA

XI

Cumulative Occurrences per 1000 Flights

A-8

1

103

With

out

Thr

us t

Rev

erse

rs

With

Tru

s t R

ever

se rs

1127

1 F

l ight

s 10

0

102

10 -1

101

10 -2

100

10 -3

10-1

10

-4

10-2

10

-5

-1

-0.5

0

0.5

1 0

.05

0.1

0.1

5 0.

2 0

.25

0.3

0.3

5 0.

4 0

.45

117

18 F

ligh

ts

Long

itudi

nal

Loa

d Fa

ctor

, nx

(g)

Lon

gitu

dina

l Loa

dFa

ctor

,n

(g)

x

FIG

UR

E A

-15.

CU

MU

LAT

IVE

FR

EQ

UE

NC

Y O

F L

ON

GITU

DIN

AL

FIG

UR

E A

-16.

CU

MU

LAT

IVE

PR

OB

AB

ILIT

Y O

F M

AX

IMU

M

LOA

D F

AC

TO

R D

UR

ING

LA

ND

ING

RO

LL

LON

GIT

UD

INA

L LO

AD

FA

CT

OR

DU

RIN

G T

AK

EO

FF

A-9

100

1172

1 F

l ight

s 10

5

10-1

10

4

103

10-2

102

10-3

101

10-4

100

10-5

10

-1

-1

-0.8

-0

.6

-0.4

-0

.2

0 -1

.5

-1

-0.5

0

0.5

1

Taxi

Out

Ta

xi In

867

9 F

light

s

Incr

emen

tal V

erti

cal L

oa

d Fa

cto

r,Δ n

(g)

z

Long

itudi

nal

Loa

d Fa

ctor

, n

(g)

x

FIG

UR

E A

-17.

CU

MU

LAT

IVE

PR

OB

AB

ILIT

Y O

F M

INIM

UM

F

IGU

RE

A-1

8. C

UM

ULA

TIV

E F

RE

QU

EN

CY

OF

INC

RE

ME

NTA

L LO

NG

ITU

DIN

AL

LOA

D F

AC

TO

R D

UR

ING

LA

ND

ING

V

ER

TIC

AL

LOA

D F

AC

TO

R D

UR

ING

TA

XI

OP

ER

ATI

ON

S

Cumulative Occurrences per 1000 Flights

A-10

1.5

105

8679

Flig

hts

105

104

104

103

103

102

102

101

101

100

100

10-1

10-1

-1.5

-1

-0

.5

0 0.

5 1

1.5

-1.5

-1

-0

.5

0 0.

5 1

w /o

Thr

ust R

ever

ser

w it

h Th

rust

Rev

erse

r

8679

Flig

hts

Incr

emen

tal V

ertic

al L

oad

Fact

or,

Δ nz

(g)

Incr

emen

tal V

ertic

al L

oad

Fact

or,

Δ n

(g)

z

FIG

UR

E A

-19.

CU

MU

LAT

IVE

FR

EQ

UE

NC

Y O

F IN

CR

EM

EN

TAL

FIG

UR

E A

-20.

CU

MU

LAT

IVE

FR

EQ

UE

NC

Y O

F IN

CR

EM

EN

TAL

VE

RT

ICA

L LO

AD

FA

CT

OR

DU

RIN

G T

AK

EO

FF

RO

LL

VE

RT

ICA

L LO

AD

FA

CT

OR

DU

RIN

G L

AN

DIN

G R

OLL

Cumulative Occurrences per 1000 Flights

Cumulative Occurrences per 1000 Flights

A-11

1.5

FIG

UR

E A

-21.

IV

E P

RO

BA

BIL

ITY

OF

MIN

IMU

M A

ND

MA

XIM

UM

IN

CR

EM

EN

TA

L V

ER

TIC

AL

LOA

D F

AC

TO

R A

TT

OU

CH

DO

WN

AN

D S

PO

ILE

R D

EP

LOY

ME

NT

FIG

UR

E A

-22.

N

CID

EN

T I

NC

RE

ME

NTA

L V

ER

TIC

AL

LOA

DF

AC

TO

R A

ND

TO

UC

HD

OW

N G

RO

SS

WE

IGH

T

10-5

10-4

10-3

10-2

10-1

100

-1.5

-1-0

.50

0.5

11.

5

Max

imum

Loa

d F

acto

r at S

poile

r Dep

loym

ent

Min

imum

(Reb

ound

) Loa

d F

acto

r at S

poile

r Dep

loym

ent

Max

imum

Loa

d F

acto

r at T

ouch

dow

nM

inim

um (R

ebou

nd) L

oad

Fac

tor a

t Tou

chdo

wn

Cumulative Probability

Incr

em

en

tal V

ert

ica

l Lo

ad

Fa

cto

r, Δn

z (g

)

-1

-0.50

0.51

1.5 70

000

8000

090

000

1000

0011

0000

1200

0013

0000

1400

00

Max

imum

Loa

d F

acto

r at T

ouch

dow

nM

inim

um (R

ebou

nd) L

oad

Fac

tor a

t Tou

chdo

wn

Incremental Vertical Load Factor, Δnz (g)

To

uch

do

wn

Gro

ss

We

igh

t (

Lb

)

A-12

CU

MU

LAT

CO

I

100

Taxi

Out

Ta

xi In

11

72

0 F

ligh

ts

100

10-1

10-1

10-2

10-2

10-3

10-3

10-4

10-4

10-5

10-5

At L

iftof

f A

t Tou

chdo

wn

11

72

3 F

ligh

ts

0 20

40

60

80

10

0 12

0 14

0 60

80

10

0 12

0 14

0 16

0 18

0 20

0 G

rou

nd

Sp

ee

d

(Kn

ots

) C

alib

rate

d A

irs

pe

ed

(K

no

ts)

FIG

UR

E A

-23.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F G

RO

UN

D

FIG

UR

E A

-24.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F A

IRS

PE

ED

S

PE

ED

DU

RIN

G T

AX

I A

T L

IFT

OF

F A

ND

TO

UC

HD

OW

N

Cumulative Probability

Cumulative Probability

A-13

100

1172

3 F

light

s 10

0

10-1

10

-1

10-2

10

-2

10-3

10

-3

10-4

10

-4

10-5

10-5

80

100

120

140

160

180

0 2

4 6

810

1214

Lifto

ff To

uchd

own

11

72

3 F

ligh

ts

Ca

libra

ted

Airs

peed

(K

nots

) P

itch

An

gle

(De

gre

es

)

FIG

UR

E A

-25.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F A

IRS

PE

ED

FI

GU

RE

A-2

6. C

UM

UL

AT

IVE

PR

OBA

BIL

ITY

OF

PIT

CH

A

T F

LA

RE

A

NG

LE

AT

LIF

TO

FF

AN

D T

OU

CH

DO

WN

Cumulative Probability

Cumulative Probability

A-14

16

100

117

23

Flig

hts

100

10-1

10-1

10-2

10-2

10-3

10-3

10-4

10-4

10

-5

0 2

4 6

8 10

12

-4

-20

24

68

10

11

72

3 F

ligh

ts

Pitc

h R

ate

(D

egre

es

/ S

eco

nd

) P

itch

An

gle

(D

eg

ree

s)

FIG

UR

E A

-27.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F

FIG

UR

E A

-28.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F P

ITC

H

MA

XIM

UM

PIT

CH

RA

TE

AT

TA

KE

OF

F R

OT

AT

ION

A

NG

LE

AT

TO

UC

HD

OW

N P

EA

K V

ER

TIC

AL

LO

AD

FA

CT

OR

Cumulative Probability

Cumulative Probability

A-15

12

10

6 10

6

10

5 10

5

10

4 10

4

10

3 10

3

10

2 10

2

10

1 10

1

10

0 10

0

10-1

10

-1

10-2

10

-2

1391

6 H

ours

-1.5

-1

-0

.5

0 0

.5

1 1

.5

-1.5

-1

-0

.5

0 0.

5 1

Incr

em

ent

al L

oad

Fac

tor,

Δ n

(g)

Incr

emen

tal L

oad

Fact

or,

Δ n

(g)

zz

FIG

UR

E A

-29.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-3

0. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

INC

RE

ME

NT

AL

VE

RT

ICA

L G

UST

LO

AD

FA

CT

OR

B

Y F

LIG

HT

PH

AS

E

VE

RT

ICA

L G

US

T L

OA

D F

AC

TO

R P

ER

100

0 H

OU

RS

P

ER

100

0 H

OU

RS

, CO

MBIN

ED

FLI

GH

T P

HA

SE

S

Cumulative Occurrences per 1000 Hours

Dep

artu

re,

16

0.94

Hrs

C

l imb,

233

2.3

3 H

rs

Cru

ise

, 7

97 4

.72

Hrs

D

esce

nt,

258

2.8

3 H

rs

Ap p

roac

h, 8

6 5.

38 H

rs

Cumulative Occurrences per 1000 Hours

A-16

1.5

10

1 D

ep a

rture

, 30

,1 5

6 N

M

Clim

b,

8 81

,2 8

0 N

M

Cru

ise

, 3,

3 90

,9 0

0 N

M

Des

cen

t, 9

25,1

40

NM

A

ppro

a ch

, 1

56,

9 30

NM

101

10

0 10

0

10

-1

10-1

10

-2

10-2

10

-3

10-3

10

-4

10-4

10

-5

10-5

10-6

10

-6

10-7

10

-7 -1

.5

-1

-0.5

0

0.5

1

1.5

-1

.5

-1

-0.5

0

0.5

1

5,38

4,40

0 N

M

Incr

em

ent

al L

oad

Fac

tor,

Δ n

(g)

Incr

emen

tal L

oad

Fact

or,

Δ nz

(g)

z

FIG

UR

E A

-31.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-3

2. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

VE

RT

ICA

L G

UST

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

INC

RE

ME

NT

AL

VE

RT

ICA

L G

UST

LO

AD

FA

CT

OR

PE

R

MIL

E B

Y F

LIG

HT

PH

AS

E

NA

UT

ICA

L M

ILE

, CO

MB

INE

D F

LIG

HT

PH

AS

ES

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-17

1.5

Dow

nwar

d G

usts

U

pw a

rd G

usts

101

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 81

.07

Hou

rs

1228

8 N

M

101

100

100

10-1

10

-1

10-2

10

-2

10-3

10

-3

10-4

10

-4

10-5

10

-5

10-6

10

-6

0 10

2030

40

0 10

2030

40

Der

ived

Gus

t Vel

ocity

, U de

(F

t/Sec

) D

eriv

ed G

ust V

eloc

ity, U

de

(Ft/S

ec)

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 81

.07

Hou

rs

1228

8 N

M

FIG

UR

E A

-33.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, < 5

00 F

EE

T

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-18

Dow

nwar

d G

usts

U

pw a

rd G

usts

101

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 20

7.36

Hou

rs

3324

1 N

M

101

100

100

10-1

10

-1

10-2

10

-2

10-3

10-3

10-4

10-4

10-5

10-5

10-6

10-6

0 10

2030

40

0 10

2030

40

Der

ived

Gus

t Vel

ocity

, U de

(Ft

/Sec

) D

eriv

ed G

ust V

eloc

ity, U

de

(Ft/S

ec)

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 20

7.36

Hou

rs

3324

1 N

M

FIG

UR

E A

-34.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, 500

-1,5

00 F

EE

T

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-19

Dow

nwar

d G

usts

U

pw a

rd G

usts

101

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 77

5.21

Hou

rs

1580

34 N

M

101

100

100

10-1

10

-1

10-2

10

-2

10-3

10

-3

10-4

10

-4

10-5

10

-5

10-6

10

-6

0 10

2030

40

0 10

2030

40

Der

ived

Gus

t Vel

ocity

, U de

(F

t/Sec

) D

eriv

ed G

ust V

eloc

ity, U

de

(Ft/S

ec)

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 77

5.21

Hou

rs

1580

34 N

M

FIG

UR

E A

-35.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, 1,5

00-4

,500

FE

ET

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-20

Dow

nwar

d G

usts

U

pw a

rd G

usts

101

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 10

42.5

1 H

ours

26

7361

NM

101

100

100

10-1

10

-1

10-2

10

-2

10-3

10

-3

10-4

10

-4

10-5

10

-5

10-6

10

-6

0 10

2030

40

0 10

2030

40

Der

ived

Gus

t Vel

ocity

, U de

(F

t/Sec

) D

eriv

ed G

ust V

eloc

ity, U

de

(Ft/S

ec)

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 10

42.5

1 H

ours

26

7361

NM

FIG

UR

E A

-36.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, 4,5

00-9

,500

FE

ET

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-21

Dow

nwar

d G

usts

U

pw a

rd G

usts

101

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 18

97.1

4 H

ours

65

8131

NM

101

100

100

10-1

10

-1

10-2

10

-2

10-3

10

-3

10-4

10

-4

10-5

10

-5

10-6

10

-6

0 10

2030

40

0 10

2030

40

Der

ived

Gus

t Vel

ocity

, U de

(F

t/Sec

) D

eriv

ed G

ust V

eloc

ity, U

de

(Ft/S

ec)

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 18

97.1

4 H

ours

65

8131

NM

FIG

UR

E A

-37.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, 9,5

00-1

9,50

0 F

EE

T

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-22

40

FIG

UR

E A

-38.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, 19,

500-

29,5

00 F

EE

T

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 30

66.8

4 H

ours

13

0733

0 N

M

(Ft/S

ec)

Der

ived

Gus

t Vel

ocity

, U de

3020

Upw

ard

Gus

ts

100

101

100

10-1

10-2

10-3

10-4

10-5

10-6

10-7

Cumulative Occurrences per Nautical Mile

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 30

66.8

4 H

ours

13

0733

0 N

M

40

(Ft/S

ec)

Der

ived

Gus

t Vel

ocity

, U de

3020

Dow

nwar

d G

usts

100

101

100

10-1

10-2

10-3

10-4

10-5

10-6

10-7

Cumulative Occurrences per Nautical Mile

A-23

Dow

nwar

d G

usts

U

pw a

rd G

usts

101

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 81

.07

Hou

rs

1228

8 N

M

101

100

100

10-1

10-1

10-2

10-2

10-3

10-3

10-4

10-4

10-5

10-5

10-6

10-6

10

-7

0 10

2030

40

0 10

2030

40

Der

ived

Gus

t Vel

ocity

, U de

(F

t/Sec

) D

eriv

ed G

ust V

eloc

ity, U

de

(Ft/S

ec)

B-7

37 D

ata

NA

CA

TN

-433

2 84

48 F

light

s 64

83.3

6Hou

rs

2808

300

NM

FIG

UR

E A

-39.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

DE

RIVE

D G

US

T V

ELO

CIT

Y P

ER

NA

UT

ICA

L M

ILE

, 29,

500-

39,5

00 F

EE

T

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-24

101

100

Cu

mul

ativ

e O

ccur

renc

es p

er N

autic

al M

ile

Cu

mul

ativ

e O

ccur

renc

es p

er N

autic

al M

ile

8448 Flights 992.64 Hours 180678 NM

FAR 25.345 Limits

10-1

10-2

10-3

10-4

10-5

10-6

-100 -80 -60 -40 -20 0 20 40 60 80 100Derived Gust Velocity, U

de (Ft/Sec EAS)

FIGURE A-40. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PERNAUTICAL MILE, FLAPS EXTENDED

100

10-1

10-2

10-3

10-4

10-5

8448 Flights 12560.84 Hours

5064008 NM

FAR 25.341Limits

10-6

10-7

10-8

-100 -80 -60 -40 -20 0 20 40 60 80 100Derived Gust Velocity, U

de (Ft/Sec EAS)

FIGURE A-41. CUMULATIVE OCCURRENCES OF DERIVED GUST VELOCITY PERNAUTICAL MILE, FLAPS RETRACTED

A-25

101

100

Cum

ula

tive

Occ

urr

en

ces

pe

r N

au

tica

l Mile

C

um

ula

tive

Occ

urr

en

ces

pe

r N

au

tica

l Mile

8448 Flights 992.64 Hours 180678 NM

10-1

10-2

10-3

10-4

10-5

10-6

-160 -120 -80 -40 0 40 80 120 160Continuous Gust Intensity, U (Ft/Sec TAS)

σ

FIGURE A-42. CUMULATIVE OCCURRENCES OF CONTINUOUS GUST INTENSITYPER NAUTICAL MILE, FLAPS EXTENDED

100

10-1

10-2

10-3

10-4

8448 Flights 12560.84 Hours

5064008 NM

10-5

10-6

10-7

-160 -120 -80 -40 0 40 80 120 160Continuous Gust Intensity, U (Ft/Sec TAS)

σ

FIGURE A-43. CUMULATIVE OCCURRENCES OF CONTINUOUS GUST INTENSITYPER NAUTICAL MILE, FLAPS RETRACTED

A-26

106

<5

00 F

eet

, 1.

08

Ho

urs

50

0-15

00

Fe

et,

2.7

5 H

ou

rs

15

00-4

50

0 F

ee

t, 4

.14

Ho

urs

45

00-9

50

0 F

ee

t, 0

.18

Ho

urs

106

105

105

104

104

103

103

102

102

101

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

50

0-1

,50

0 F

t, 0

.02

9 H

rs

1,5

00

-4,5

00

Ft,

7.7

1 H

rs

4,5

00

-9,5

00

Ft,

21

.0 H

rs

9,5

00

-14

,50

0 F

t, 3

2.4

9 H

rs

14

,50

0-1

9,5

00

Ft,

33

.38

Hrs

19

,50

0-2

4,5

00

Ft,

42

.9 H

rs

24

,50

0-2

9,5

00

Ft,

50

.11

Hrs

29

,50

0-3

4,5

00

Ft,

42

.02

Hrs

34

,50

0-3

9,5

00

Ft,

15

.15

Hrs

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

Incr

em

ent

al L

oad

Fa

cto

r, Δ n

(g)

Incr

em

en

tal L

oa

d F

act

or, Δ

n z (g

) z

FIG

UR

E A

-44.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-4

5. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

INC

RE

ME

NT

AL

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

INC

RE

ME

NT

AL

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

HO

UR

S D

UR

ING

DE

PAR

TU

RE

BY

ALT

ITU

DE

H

OU

RS

DU

RIN

G C

LIM

B B

Y A

LT

ITU

DE

Cumulative Occurrences per 1000 Hours

Cumulative Occurrences per 1000 Hours

A-27

106

50

0-1,

50

0 F

t, 0

.00

28

Hrs

1,5

00

-4,5

00 F

t, 1

.33H

rs

4,5

00

-9,5

00 F

t, 9

.43

Hrs

9,5

00

-14

,50

0 F

t, 1

7.9

7Hrs

14

,50

0-1

9,5

00

Ft,

11

.16

Hrs

19

,50

0-2

4,5

00

Ft,

49

.19

Hrs

24

,50

0-2

9,5

00

Ft,

13

6.9

9 H

rs

29

,50

0-3

4,5

00

Ft,

42

9.6

1 H

rs

34

,50

0-3

9,5

00

Ft,

28

5.9

1 H

rs

106

105

105

104

104

103

103

102

102

101

100

101

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

0 0.

05

0.1

0.15

0.

2 0.

25

50

0-1

,50

0 F

t, 0

.05

8 H

rs

1,5

00

-4,5

00

Ft,

8.2

3 H

rs

4,5

00

-9,5

00

Ft,

35

.3 H

rs

9,5

00

-14

,50

0 F

t, 5

2.4

3 H

rs

14

,50

0-1

9,5

00

Ft,

39

.82

Hrs

1

9,5

00

-24

,50

0 F

t, 4

8.1

3 H

rs

24

,50

0-2

9,5

00

Ft,

45

.71

Hrs

2

9,5

00

-34

,50

0 F

t, 2

5.5

5 H

rs

34

,50

00

-39

,50

0 F

t, 1

.74

Hrs

Incr

em

en

tal L

oa

d F

act

or, Δ

n -

(g)

zIn

cre

me

nta

l Loa

d F

act

or, Δ

n (g

)z

FIG

UR

E A

-46.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-4

7. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

INC

RE

ME

NT

AL

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

HO

UR

S D

UR

IN

G

HO

UR

S D

UR

ING

CR

UIS

E B

Y A

LT

ITU

DE

D

ES

CE

NT

BY

AL

TIT

UD

E

Cumulative Occurrences per 1000 Hours

Cumulative Occurrences per 1000 Hours

A-28

106

<5

00

Ft,

2.4

6 H

rs

50

0-1

,50

0 F

t, 6

.65

Hrs

1,5

00

-4,5

00

Ft,

23

.44

Hrs

4,5

00

-9,5

00

Ft,

10

.35

Hrs

9,5

00

-14

,50

0 F

t, 0

.54

Hrs

14

,50

0-1

9,5

00

Ft,

0.0

04

5 H

rs

10-1

105

10-2

104

10-3

103

10-4

102

10-5

101

10-6

0 0.

1 0.

2 0.

3 0.

4 0.

5 0.

6 0.

7

<50

0 F

t, 8

2501

NM

500

-1,5

00

Ft,

199

608

NM

1,5

00-4

,50

0 Ft

, 2

7223

NM

4,5

00-9

,50

0 Ft

, 1

0935

NM

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

Incr

em

en

tal L

oa

d F

act

or, Δ

n z (g

) In

cre

me

ntal

Loa

d F

acto

r, Δ n

(g)

z

FIG

UR

E A

-48.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-4

9. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

HO

UR

S D

UR

IN

G

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E

AP

PR

OA

CH

BY

AL

TIT

UD

E

DU

RIN

G D

EPA

RT

UR

E B

Y A

LTIT

UD

E

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per 1000 Hours

A-29

10-1

10-1

10-2

50

0-1

,50

0 F

t, 1

65

0 N

M

1,5

00

-4,5

00

Ft,

42

00

19

Nm

4

,50

0-9

,50

0 F

t, 1

01

15

25

NM

9

,50

0-1

4,5

00

Ft,

12

69

76

1 N

M

14

,50

0-1

9,5

00

Ft,

11

41

37

7 N

M

19

,50

0-2

4,5

00

Ft,

13

50

30

7 N

M

24

,50

0-2

9,5

00

Ft,

14

90

68

9 N

M

29

,50

0-3

4,5

00

Ft,

12

53

18

5 N

M

34

,50

0-3

9,5

00

Ft,

45

78

42

NM

10-2

10-3

10

-3

10-4

10

-4

10-5

10

-5

10-6

10

-6

10-7

10

-7

500

-1,5

00

Ft,

161

NM

1

,500

-4,5

00

Ft,

723

24

NM

4

,500

-9,5

00

Ft,

471

150

NM

9

,500

-14

,50

0 F

t, 7

47

855

NM

1

4,50

0-1

9,5

00 F

t, 4

00

115

NM

1

9,50

0-2

4,5

00 F

t, 1

538

495

NM

2

4,50

0-2

9,5

00 F

t, 4

070

102

NM

2

9,50

0-3

4,5

00 F

t, 1

278

9833

NM

3

4,50

0-3

9,5

00 F

t, 8

619

328

NM

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

0

0.05

0.

1 0.

15

0.2

Incr

em

en

tal L

oa

d F

act

or, Δ

n (g

) In

cre

me

nta

l Lo

ad F

acto

r, Δ n

(g)

zz

FIG

UR

E A

-50.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-5

1. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E

DU

RIN

G C

LIM

B B

Y A

LT

ITU

DE

D

UR

ING

CR

UIS

E B

Y A

LT

ITU

DE

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-30

0.25

10-2

50

0-1

,50

0 F

t, 3

18

9 N

M

1,5

00

-4,5

00

Ft,

43

60

33

NM

4

,50

0-9

,50

0 F

t, 1

71

57

38

NM

9

,50

0-1

4,5

00

Ft,

20

60

311

NM

1

4,5

00

-19

,50

0 F

t, 1

37

76

81

NM

1

9,5

00

-24

,50

0 F

t, 1

52

27

43

NM

2

4,5

00

-29

,50

0 F

t, 1

36

70

38

NM

2

9,5

00

-34

,50

0 F

t, 7

62

63

6 N

M

34

,50

0-3

9,5

00

Ft,

52

79

6 N

m

10-2

10-3

10-3

10-4

10-4

10-5

10-5

10-6

10-7

10

-6

<500

Ft,

21

9647

NM

500-

1,50

0 Ft

, 5

6283

1 N

M

1,50

0-4

,500

Ft,

165

0915

NM

4,50

0-9

,500

Ft,

643

585

NM

9,50

0-1

4,50

0 Ft

, 2

9830

NM

14,5

00-

19,5

00 F

t, 2

25

NM

0 0.

05

0.1

0.15

0.

2 0.

25

0.3

0.35

0

0.1

0.2

0.3

0.4

0.5

0.6

Incr

emen

tal L

oad

Fac

tor, Δ

n (g

)In

cre

me

nta

l Lo

ad F

act

or,Δ

n (g

) z

z

FIG

UR

E A

-52.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-5

3. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E

DU

RIN

G D

ESC

EN

T B

Y A

LT

ITU

DE

D

UR

ING

APP

RO

AC

H B

Y A

LT

ITU

DE

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-31

0.7

105

Dep

artu

re,

160.

94 H

ours

Clim

b, 2

332.

2 H

ours

Cru

ise,

797

4.8

Hou

rs

Des

cent

, 2

582.

8 H

ours

App

roac

h, 8

65.8

Hou

rs

104

104

103

103

102

102

101

101

100

100

10-1

10-1

10

-2

0 0.

1 0.

2 0.

3 0.

4 0.

5 0.

6 0.

7 0.

8 0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

1391

6 H

ours

Man

euve

r Lo

ad F

acto

r, Δ

n z (g

) M

aneu

ver

Load

Fac

tor,

Δ n

(g)

z

FIG

UR

E A

-54.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-5

5. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

BY

FL

IGH

T P

HA

SE

C

OM

BIN

ED

FLI

GH

T P

HA

SE

S

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

HO

UR

S

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R 1

000

HO

UR

S,

Cumulative Occurrences per 1000 Flight Hours

Cumulative Occurrences per 1000 Flight Hours

A-32

100

Dep

artu

re,

30,1

56 N

M

Clim

b, 8

81,2

80 N

M

Cru

ise,

3,3

90,9

00 N

M

Des

cent

, 9

25,1

40 N

M

App

roac

h, 1

56,9

30 N

M

100

10-1

10-1

10-2

10-2

10-3

10-3

10-4

10-4

10-5

10-5

10-6

10-6

10

-7

0 0.

1 0.

2 0.

3 0.

4 0.

5 0.

6 0.

7 0.

8 0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

5,38

4,40

0 N

M

Man

euve

r Lo

ad F

acto

r, Δ

n (g

) M

aneu

ver

Load

Fac

tor,

Δ n

(g)

zz

FIG

UR

E A

-56.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-5

7. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E

MA

NE

UV

ER

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E,

BY

FL

IGH

T P

HA

SE

C

OM

BIN

ED

FLI

GH

T P

HA

SE

S

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-33

106

106

105

105

104

104

103

103

102

102

101

101

100

100

10-1

10

-1

10-2

-1.5

-1

-0

.5

0 0

.5

1 1

.5

-

1391

6 H

ours

1.5

-1

-0.5

0

0.5

1 In

cre

me

nta

l Lo

ad F

acto

r,

Δ nz

(g)

Incr

emen

tal L

oad

Fact

or,

Δ n

(g)

z

FIG

UR

E A

-58.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-5

9. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

CO

MB

INE

D M

AN

EU

VE

R A

ND

GU

ST V

ER

TIC

AL

LO

AD

V

ER

TIC

AL

LO

AD

FA

CT

OR

PE

R 1

000

HO

UR

S,

FA

CT

OR

PE

R 1

000

HO

UR

S BY

FLI

GH

T P

HA

SE

C

OM

BIN

ED

FLI

GH

T P

HA

SE

S

Cumulative Occurrences per 1000 Hours

De

part,

16

0.94

Hrs

C

li mb,

23

32.2

Hrs

C

rui s

e,

79 7

4.8

Hrs

D

es

cen

t, 25

82.

8 H

rs

App

roa

ch,

86 5

.38

Hrs

Cumulative Occurrences per 1000 Hours

A-34

1.5

101

Dep

a rt,

301

56

NM

C

l imb,

88

12 7

8 N

M

Cru

ise,

3 3

908

57 N

M

Des

cent

, 92

51 4

3 N

M

App

roac

h, 1

569

30 N

M

100

100

10-1

10-1

10-2

10-2

10-3

10-3

10-4

10-4

10-5

10-5

10-6

10-6

10-7

10

-7

-1.5

-1

-0

.5

0 0.

5 1

1.5

-1.5

-1

-0

.5

0 0.

5 1

5,38

4,40

0 N

M

Incr

em

ent

al L

oad

Fac

tor,

Δ n

(g)

Incr

emen

tal L

oad

Fact

or,

Δ n

(g)

zz

FIG

UR

E A

-60.

CU

MU

LA

TIV

E O

CC

UR

RE

NC

ES

OF

FI

GU

RE

A-6

1. C

UM

UL

AT

IVE

OC

CU

RR

EN

CE

S O

F

VE

RT

ICA

L L

OA

D F

AC

TO

R P

ER

NA

UT

ICA

L M

ILE

BY

V

ER

TIC

AL

LO

AD

FA

CT

OR

PE

R N

AU

TIC

AL

MIL

E,

FLI

GH

T P

HA

SE

C

OM

BIN

ED

FLI

GH

T P

HA

SE

S

Cumulative Occurrences per Nautical Mile

Cumulative Occurrences per Nautical Mile

A-35

1.5

106

105

104

19105.01 Hours C

um

ula

tive

Occ

urr

enc

es p

er 1

000

Hou

rs

103

102

101

100

10-1

10-2

-0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 Incremental Load Factor, n (g)

y

FIGURE A-62. CUMULATIVE OCCURRENCES OF LATERAL LOAD FACTOR PER 1000 HOURS, COMBINED FLIGHT PHASES

A-36

A-37

FIGURE A-63. INCIDENT MANEUVER LOAD FACTOR AND SPEED VERSUS V-nDIAGRAM FOR FLAPS RETRACTED

FIGURE A-64. COINCIDENT MANEUVER LOAD FACTOR AND SPEED VERSUS V-nDIAGRAM FOR FLAPS EXTENDED

-2

-1

0

1

2

3

0 100 200 300 400

Loa

d F

act

or, n

z (g

)

Velocity(KEAS)

V-n Diagr am For Illust ration Onl y

-2

-1

0

1

2

3

0 100 200 300 400

Load

Fa

ctor

, nz

(g)

Velocity(KEAS)

V-n Diagr am For Illus tration Only

CO

A-38

FIGURE A-65. INCIDENT GUST LOAD FACTOR AND SPEED VERSUS V-nDIAGRAM FOR FLAPS RETRACTED

FIGURE A-66. INCIDENT GUST LOAD FACTOR AND SPEED VERSUS V-nDIAGRAM FOR FLAPS EXTENDED

-2

-1

0

1

2

3

0 50 100 150 200 250 300 350 400Load

Fac

tor,

nz

(g)

Velocity(KEAS)

V-n Diagram For Illustration Only

-2

-1.5

-1

-0.5

0

0.5

1

1.5

2

0 50 100 150 200 250 300 350 400

Velocity(KEAS)

V-n Diagram For Illustration Only

CO

CO

1 Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30

0.8 C

um

ula

tive

Pro

ba

bili

ty

Cum

ulat

ive

Pro

bab

ility

0.6

0.4

0.2

0

120 140 160 180 200 220 240 260 Calibrated Airspeed (Knots)

FIGURE A-67. CUMULATIVE PROBABILITY OF MAXI MUM AI RSPEED IN FLAPDETENT DURING DEPARTURE

1

0.8

0.6

0.4

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30 Detent 40 Detent 45

0.2

0

120 140 160 180 200 220 240 260

Calibrated Airspeed (Knots)

FIGURE A-68. CUMULATIVE PROBABILITY OF MAXI MUM AI RSPEED IN FLAPDETENT DURING APPROACH

A-39

A-40

FIGURE A-69. TIME IN FLAP DETENT DURING DEPARTURE

FIGURE A-70. TIME IN FLAP DETENT DURING APPROACH

0

20

40

60

80

100

1 5 10 15 25 30 40 45

Percent of Departure Hours (217.6 Hrs)Percent of Total Flight Hours (19105 Hrs)

Pe

rce

nt o

f Tim

e

5.2Hours

211.2Hours

0.5Hours

0.6Hours

0.1Hours

Flap Detent

0

10

20

30

40

50

1 5 10 15 25 30 40 45

Percent of Approach Hours (1166.9 Hrs)Percent of Total Flight Hours (19105 Hrs)

Pe

rce

nt o

f Tim

e

3.1Hours

407.5Hours

247.4 Hours

2.8Hours

155.1Hours

333.1Hours

0.9Hours

17.1Hours

Flap Detent

PERCENT OF

PERCENT OF

1

0.8

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30

Cu

mu

lativ

e P

rob

abi

lity

Cu

mu

lativ

e P

rob

abili

ty

0.6

0.4

0.2

0

50 100 150 200 250

Dynamic Pressure, q (Lb/ft2)

FIGURE A-71. CUMULATIVE PROBABILITY OF MAXIMUM DYNAMI C PRESSURE INFLAP DETENT DURING DEPARTURE

1

0.8

0.6

0.4

Detent 1 Detent 5 Detent 10 Detent 15 Detent 25 Detent 30 Detent 40 Detent 45

0.2

0

0 50 100 150 200 250

Dynamic Pressure, q (Lb/ft2)

FIGURE A-72. CUMULATIVE PROBABILITY OF MAXIMUM DYNAMI C PRESSURE INFLAP DETENT DURING APPROACH

A-41

100

100

10-1

117

21

Flig

hts

10-1

10-2

10-2

10-3

10

-3

10-4

10

-4

10-5

10

-5

100

150

200

250

300

350

400

100

150

200

250

300

350

400

117

21 F

ligh

ts

Eq

uiv

alen

t Air

spe

ed

(Kno

ts)

Equ

iva

lent

Airs

peed

(K

nots

)

FIG

UR

E A

-73.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F

FIG

UR

E A

-74.

CU

MU

LA

TIV

E F

RE

QU

EN

CY

OF

SP

EE

D A

T

MA

XIM

UM

SP

EE

D D

UR

ING

SP

EE

D B

RA

KE

DE

PLO

YM

EN

T

SP

EE

D B

RA

KE

DE

PLO

YM

EN

T

Cumulative Probability

Cumulative Occurrences per Flight

A-42

100

117

21 F

ligh

ts

1

0.9

0.8

10-1

0.7

0.6

10-2

0.

5

0.4

0.3

10-3

0.2

0.1 0

10-4

0 10

2030

40

0 50

00

1000

0 15

000

2000

0 25

000

3000

0 35

000

4000

0

11

72

1 F

ligh

ts

De

plo

yme

nt A

ngle

(D

egr

ee

s)

Alti

tud

e (

Feet

)

FIG

UR

E A

-75.

CU

MU

LA

TIV

E F

RE

QU

EN

CY

OF

AL

TIT

UD

E

FIG

UR

E A

-76.

CU

MU

LA

TIV

E P

RO

BAB

ILIT

Y O

F

AT

SP

EE

D B

RA

KE

DE

PLO

YM

EN

T

MA

XIM

UM

DE

PL

OY

ME

NT

AN

GL

E D

UR

ING

SP

EE

D

BR

AK

E D

EPL

OY

ME

NT

, FLA

PS

RE

TR

AC

TE

D

Cumulative Probability

Cumulative Occurrences per Flight

A-43

50

100

116

50

Flig

hts

10

0

10-1

10

-1

10-2

10

-2

10-3

10

-3

10-4

10-4

10-5

10-5

0 20

40

60

80

10

0

AT

DE

PLO

YME

NT

A

T S

TOW

AG

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FIGURE A-83. ATIVE PROBABILITY OF PERCENT OF N1

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B-1

APPENDIX BGREAT CIRCLE DISTANCE CALCULATION

Given:

Latitude and Longitude ρ = distance from centerof Departure and ϕ = angle from North PoleDestination Airports θ = angle E/W of prime meridian

Procedure: (see sketch)

The standard mathematical system for spherical coordinates is shown, where three variablesspecify location: ρ, ϕ, and θ.

Let a = Great Circle Distance in angular measure.

Latitude is measured away from the Equator (0°) to the North Pole (+90°) and the South Pole(-90°); whereas in the standard spherical coordinate system, the North Pole, Equator, and SouthPole lie at 0°, 90°, and 180°, respectively. Therefore,

ϕ =

transforms latitude readings into equivalent angles (ϕ) in the standard spherical coordinatesystem.

Then

b = LatitudeDep

c = LatitudeDes

where b and c are values of ϕ for the departure and destination locations, respectively.

90° - latitude

90° - 90° -

Longitude is measured away from the prime meridian (0°). Longitudes to the east are positive and to the west negative. However, the standard spherical coordinate system measures its angles in the opposite direction. Therefore,

θ = - longitude

transforms longitude readings into equivalent angles (θ ) in the standard spherical coordinate system.

Then

A = (- LongitudeDes) - (- LongitudeDep) = LongitudeDep - LongitudeDes

where A is the value of θ between the departure and destination locations.

The following equation, based on the spherical coordinate system, allows the computation of the Great Circle Distance, a. (Law of cosines for oblique spherical triangles)

cos a = cos b cos c + sin b sin c cos A

Substituting for b, c, and A from the above equalities,

cos a = cos (90° - LatDep) cos (90° - LatDes) + sin (90° -LatDep) sin (90° - LatDes) cos (LonDep - LonDes)

Since

cos (90° -LatDep) = sin LatDep

cos (90° -LatDes) = sin LatDes

sin (90° -LatDep) = cos LatDep

sin (90° -LatDes) = cos LatDes

by replacement one obtains

cos a = sin (LatDep) sin (LatDes) + cos (LatDep) cos (LatDes) cos (LonDes - LonDep)

Thus a, the angular measure of the great circle arc connecting the departure and destination locations, is obtained as

a = cos-1 [sin (LatDep) sin (LatDes) + cos (LatDep) cos (LatDes) cos (LonDes - LonDep)]

So, for a expressed in radians

GCD = a radians 180deg. 60 min. 1nm 10800a

π radians

1deg.

1min.

=

π nm

and for a expressed in degrees,

60 min. 1nm GCD = a degrees

1deg.

1min.

= 60a nm

B-2

Appendix – List of FAA Technical Reports Published in FY98

Report Number Title

R&D Highlights 1998 Highlights of the major accomplishments and applications.

DOT/FAA/AR-TN97/50 Comparison of Radial and Bias-Ply Tire Heating on a B-727 Aircraft

DOT/FAA/AR-97/99 Fire-Resistant Materials: Research Overview

DOT/FAA/AR-95/18 User’s Manual for the FAA Research and Development Electromagnetic Database (FRED)

DOT/FAA/AR-97/7 Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

DOT/FAA/AR-97/26 Impact of New Large Aircraft on Airport Design

DOT/FAA/AR-97/64 Operational Evaluation of a Health and Usage Monitoring Systems (HUMS)

DOT/FAA/AR-TN98/15 Fire Testing of Ethanol-Based Hand Cleaner

DOT/FAA/AR-95/111 Stress-Intensity Factors for Elliptical Cracks Emanating from Countersunk Rivet Holes

DOT/FAA/AR-97/9 An Acoustic Emission Test for Aircraft Halon 1301 Fire Extinguisher Bottles

DOT/FAA/AR-97/37 Development of an Improved Magneto-Optic/Eddy-Current Imager

DOT/FAA/AR-97/69 Automated Inspection of Aircraft

DOT/FAA/AR-97/5 Marginal Aggregates in Flexible Pavements: Field Evaluation

DOT/FAA/AR-97/87 A Predictive Methodology for Delamination Growth in Laminated Composites, Part I: Theoretical Development and Preliminary Experimental Results

DOT/FAA/AR-TN97/103 Initial Development of an Exploding Aerosol Can Simulator

DOT/FAA/AR-97/56 Applications of Fracture Mechanics to the Durabilit y of Bonded Composite Joints

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Report Number Title

DOT/FAA/AR-96/97 Stress-Intensity Factors Along Three-Dimensional Elliptical Crack Fronts

DOT/FAA/AR96/119 Vertical Drop Test of a Beechcraft 1900C Airliner

DOT/FAA/AR-98/22 FAA T53-L-13L Turbine Fragment Containment Test

DOT/FAA/AR-97/85 Response and Failure of Composite Plates with a Bolt-Filled Hole

DOT/FAA/AR-98/26 A Review of the Flammabilit y Hazard of Jet A Fuel Vapor in Civil Transport Aircraft Fuel Tanks

DOT/FAA/AR-TN97/108 Effects of Concentrated Hydrochloric Acid Spills on Aircraft Aluminum Skin

DOT/FAA/AR-TN98/32 Cargo Compartment Fire Protection in Large Commercial Transport Aircraft

DOT/FAA/AR-98/28 Statistical Loads Data for Boeing 737-400 Aircraft in Commercial Operations

DOT/FAA/AR-97/47 Development of Advanced Computational Models for Airport Pavement Design

DOT/FAA/AR-98/34 Health Hazards of Combustion Products From Aircraft Composite Materials

DOT/FAA/AR-97/81 Bioremediation of Aircraft Deicing Fluids (Glycol) at Airports

DOT/FAA/AR-TN97/8 Heats of Combustion of High-Temperature Polymers

DOT/FAA/AR-95/29

FACT SHEETS

Fiber Composite Analysis and Design: Composite Materials and Laminates, Volume I

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