Federal AviationAdministrationCOMFAA AdministrationCO
Demonstration and Hands-On TrainingHands-On Training
Presented to: VII ALACPA Airport Pavement Seminar & V FAA Airport Pavement Workshop
By: David R. Brill, P.E., Ph.D.
Date: December 8, 2010
Acknowledgmentsg
Gordon Ha hoe Rodne Joel and Jeff• Gordon Hayhoe, Rodney Joel and Jeff Rapol, FAA.
• Ken DeBord and Mike Roginski, Boeing Commercial Airplane Co.
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COMFAA DemonstrationDecember 8, 2010
Outline
Brief re ie of ACN/PCN s stem and ICAO• Brief review of ACN/PCN system and ICAO definitions.
• FAA guidance on PCN calculation.
• Draft AC 150/5335-5B and computer programs (COMFAA 3.0 and new support program).
• Flexible example using COMFAA 3.0.Flexible example using COMFAA 3.0.
• Rigid example using COMFAA 3.0 for a large hub airporthub airport.
• Using COMFAA 3.0 additional features.
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COMFAA DemonstrationDecember 8, 2010
The ACN/PCN System - Generaly
• Aircraft Classification Number (ACN) is specified as a standard by ICAO in Annex 14 to the Conventiona standard by ICAO in Annex 14 to the Convention on International Civil Aviation.
Aircraft manufacturers are required to publish properly– Aircraft manufacturers are required to publish properly computed ACN values for all of their aircraft.
• Pavement Classification Number (PCN) procedures• Pavement Classification Number (PCN) procedures are given in the ICAO Aerodrome Design Manual, Part 3, Pavements.,
– The PCN procedures in the manual are for guidance only and a great deal of latitude is provided.
– Airport operators are responsible for determining and publishing PCN values for runways.
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ICAO Documents Annex 14 to the Convention on International Civil Aviation
ICAO Aerodrome Design ManualPart 3 – Pavements
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ACN/PCN System - Definitionsy
• ACN A number expressing the relative effect of an• ACN – A number expressing the relative effect of an aircraft on a pavement for a specified standard subgrade strength.subgrade strength.
• PCN - A number expressing the bearing strength of a pavement for unrestricted operations.p p
• Therefore, if a particular aircraft at a given weight has an ACN less than, or equal to, the PCN of a particular pavement (ACN ≤ PCN), then no restrictions need to be placed on operation of that aircraft on that pavementaircraft on that pavement.
• Special provisions for overload evaluation.
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ACN Computationp
• ACN is computed as the ratio of a computed• ACN is computed as the ratio of a computed (derived) single-wheel load to a reference single-wheel load.wheel load.– Flexible: Based on the US Army Corps of Engineers ESWL
CBR method of design using alpha factors adopted by ICAO O t b 2007 Thi k i t d f 10 000October 2007. Thickness is computed for 10,000 coverages.
– Rigid: PCA Westergaard interior stress method of design. Thickness is computed for 10,000 coverages.p g
• These are fixed, standard procedures. Other design procedures or traffic levels cannot be substituted.
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Subgrade Strength for ACN Computationg g p
Fle ible The CBR of the s bgrade soil• Flexible: The CBR of the subgrade soil.
• Rigid: The k-value at the top of the support, including all subbase layers. – It is not the same as the k-value of the subgrade
soil.
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PCN Reporting Formatp g
PCN al es are reported in a coded format• PCN values are reported in a coded format using 5 parts separated by “/”
S l 39/F/B/X/TSample 39/F/B/X/T
• Information includes:– Numerical PCN Value (39 in this example)
– Pavement Type (F = Flexible, R = Rigid)
– Subgrade Strength Category (A, B, C or D)
– Allowable Tire Pressure (X ≤ 1.5 MPa = 218 psi)
– PCN Evaluation Method (U = Using, T = Technical)
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COMFAA DemonstrationDecember 8, 2010
Proposed Change to ICAO PCN Tire Pressure Limits (Flexible Only)
Tire Pressure Category
Current ICAO Designations and Limits
Proposed ICAO Designations and Limitsg y g g
W High: no pressure limit Unlimited
X Medium: pressure limited High: pressure limited to X to 1.50 MPa (217.6 psi) 1.75 MPa (253.8 psi)
Y Low: pressure limited to1.00 MPa (145.0 psi)
Medium: pressure limited to 1.25 MPa (181.3 psi)
Z Very low: pressure limited to 0.50 MPA (72.5 psi)
Low: pressure limited to0.50 MPA (72.5 psi)
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COMFAA DemonstrationDecember 8, 2010
PCN – Using Aircraft Methodg
Find the ACN of all of the aircraft reg larl• Find the ACN of all of the aircraft regularly using the pavement and pick the largest ACN to be the PCN of the pavementACN to be the PCN of the pavement.
• But see page 3-27 of the ICAO manual:“Support of a particularly heavy load, but only rarely, does not necessarily establish a capability to support eq i alent loads on a reg lar repetiti e basis ”equivalent loads on a regular repetitive basis.”
Where is the line between “regular” and l d ti ?overload operation?
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PCN – Technical Method
The ICAO man al co ers in detail a er• The ICAO manual covers in detail a very broad range of methods, including:
A ti l d i d d l d ifi ll– Any rational design procedure developed specifically for airport pavements but applied in reverse for pavement evaluationpavement evaluation.
– Pavement surface deflection measured under the load from a representative aircraft.load from a representative aircraft.
– Non-destructive test results with backcalculation.
– Allows for design and evaluation procedures not inAllows for design and evaluation procedures not in use when the manual was written.
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FAA Guidance on PCN Calculation
The FAA is responsible for certif ing all• The FAA is responsible for certifying all commercial airports in the U.S. and is the organization generally responsible fororganization generally responsible for complying with international agreements on aviationaviation.
• Well defined procedures are therefore required for determining and publishing PCN values for runways at all commercial
Sairports in the U.S.
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AC 150/5335-5A (2006)St d di d M th d f R ti Ai t P t St th PCNStandardized Method of Reporting Airport Pavement Strength – PCN
• Complete rewrite of AC 150/5335 5• Complete rewrite of AC 150/5335-5.
• Standardized the procedures for computing and reporting PCN values for inclusion in the 5010reporting PCN values for inclusion in the 5010 database.
• AC 150/5335-5A is based in large part on theAC 150/5335 5A is based in large part on the procedures described in Boeing Report D6-82203 “Precise Methods for Estimating Pavement Classification Number,” 1998.
• D6-82203 is, in turn, based largely on d i i d i h ICAOrecommendations contained in the ICAO
Aerodrome Design Manual.
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Draft Advisory Circular 150/5335-5By
• AC 150/5335 5A PCN• AC 150/5335-5A, PCN, to be replaced by AC 150/5335-5B.150/5335 5B.
• Draft AC was posted for comment October 2009.
• Comment period has ended.
• Copy of draft AC is i l d d h CDincluded on the CD.
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AC 150/5335-5B STANDARDIZED METHOD OF REPORTING AIRPORT PAVEMENTSTANDARDIZED METHOD OF REPORTING AIRPORT PAVEMENT STRENGTH - PCN
The Pavement Classification Number (PCN) field has• The Pavement Classification Number (PCN) field has been added to FAA Form 5010 and data collection is underway.underway.
• During each airport inspection, the airport owner will be asked to provide runway PCN information.p y
• WHY? – With release of AC 150/5320-6E, the “design aircraft” concept
has been replaced.
– This means the Aircraft Gross Weight fields on the 5010 will no longer be used to describe load carrying capacity of runwayslonger be used to describe load carrying capacity of runways.
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AC 150/5335-5B …PCN
Gross Weight data
may transition.
PCN data request now part of all airport inspections
• The Master Record is required to be updated periodically.
PCN i d t d G W i ht d t ill ibl b
of all airport inspections
• PCN is now mandatory and Gross Weight data will possibly be phased out with time.
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COMFAA DemonstrationDecember 8, 2010
Draft AC 150/5335-5B Changes from AC 150/5335 5A- Changes from AC 150/5335-5A
• The procedure for selecting the critical aircraft has• The procedure for selecting the critical aircraft has been substantially revised.
• The procedure for computing equivalent departures• The procedure for computing equivalent departures has been replaced by a new procedure based on cumulative damage factor (CDF).g ( )
• Except for obtaining the structure and aircraft properties, the procedure has been completely automated in a revised version of the computer program COMFAA (COMFAA 3.0).
A d h li i h b d l d• A spreadsheet application has been developed to facilitate determining the evaluation thickness.
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COMFAA DemonstrationDecember 8, 2010
Draft AC 150/5335-5B
• The design procedures recommended in the new• The design procedures recommended in the new AC are:– CBR ESWL with the new alpha factors for flexible pavements.CBR ESWL with the new alpha factors for flexible pavements.
– Edge stress Westergaard as implemented in AC 150/5320-6C and -6D.
– The PCA center stress method can also be selected in COMFAA 3.0.
• These were selected for backward compatibility• These were selected for backward compatibility with established methods and compatibility with the ACN computation procedure.p p
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COMFAA DemonstrationDecember 8, 2010
New PCN Methodology• The current methodology (-5A) finds the critical
aircraft and then finds the ACN of that aircraft at the maximum allowable gross weight. That ACN is then the PCN.
• The new methodology is the same except that the ACN at maximum allowable gross weight is
l l t d f ll f th i ft i th i Th CDFcalculated for all of the aircraft in the mix. The CDF procedure is used for equivalent coverages.
• The largest ACN value is then selected as the PCN• The largest ACN value is then selected as the PCN.
• There is a need to eliminate “occasional or overload” aircraft from the mixoverload aircraft from the mix.
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COMFAA DemonstrationDecember 8, 2010
ACN-PCN – Technical Evaluation
7 Basic Steps to Determine Pavement7 Basic Steps to Determine Pavement Classification Number in AC 150/5335-6B:
1 Identify pavement features and properties1. Identify pavement features and properties.
2. Determine traffic mixture.
3 Convert traffic to equivalent traffic of “critical” aircraft3. Convert traffic to equivalent traffic of critical aircraft.
4. Determine allowable operating weight of critical airplaneairplane.
5. Determine ACN of critical airplane at allowable weight.
6 Repeat with each airplane the critical airplane6. Repeat with each airplane the critical airplane.
7. Report PCN.
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AC 150/5335-5B Computer Programsp g
COMFAA 3 0 Program• COMFAA 3.0 Program
• Support Spreadsheet for COMFAA (Excel)Input Support:
– Flexible Layer Equivalency Worksheet
– Rigid Pavement k-Value Worksheet
Output Support:
– Output Data Parsing
– Rigid and Flexible Chart Creation
– FAA Form 5010 Preparation
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support Spreadsheetpp p
Flexible Layer EquivalencyFlexible Layer Equivalency
– The equivalent pavement has three layers:
5 i P 401• 5 in. P-401,
• 8 in. P-209,
• P-154.
– The spreadsheet determines the maximum thickness for the
i l t tequivalent pavement based on the user-defined layer equivalency f tfactors.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetFl ibl P t I tFlexible Pavement Input
• ENTER (or confirm)
Fig. A2-2 Figs. A2-1, A2-2Flexible Pavement Convert Convert
Structure Items to P-209 to P-154
Existing Flexible
Pavement Layers
Reference Guidance AC 150/5335-5B Appendix A-2Existing Layer
Thickness
• ENTER (or confirm) layer equivalency factors.
P-401 and/or P-403 1.6 2.0ENTER P-401 and/or P-403 6.0 in.
P-306 1.2 1.6 ENTER P-306 0.0 in.
Layers Thickness1.41.51.6
1.81.92.0
1.21.31.4
1.3
1.61.71.8
1.6
factors.– Refer to Table A2-1.
• ENTER all existing P-304 1.2 1.6 ENTER P-304 0.0 in.
P-209 1.0 1.4 ENTER P-209 12.0 in.
ENTER P-208
1.31.41.5
1.61.71.8
1.21.31.4
1.31.4
gpavement layers starting at the surface
f th t P-208 and/or P-211 1.0 1.3 and/or P-211 0.0 in.
P-301 n/a 1.0 ENTER P-301 0.0 in.
P-154 n/a 1.0 ENTER P-154 13.0 in.
1.01.11.2
1.5of the pavement.
• ENTER the subgrade CBR value Equivalent Thickness, in. 9.0
ENTER Subgrade CBRCBR value.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetFl ibl P t O t t
0
Existing Pavement Equivalent Pavement
Flexible Pavement Output
COMFAA Evaluation Criteria P-401P-401
P-209
P-209
5
10
in.
COMFAA Evaluation Criteria
Evaluation thickness t = 33.8 in.
Evaluation CBR = 9.0
P-154
15
20
25th f
rom
Su
rfac
e, i
Recommended PCN Codes: F/B/W or Recommended PCN Codes: F/B/X
P-154
Subgrade
Subgrade CBR 9.0
25
30
35
Dep
t
PAVEMENT TO BE EVALUATED IN COMFAA
CBR 9.0
• The spreadsheet determines and consolidates COMFAA software input values and recommends three of five necessary PCN codes.p y
• The spreadsheet updates the graphical representation of the existing and equivalent pavement.
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COMFAA DemonstrationDecember 8, 2010
Using the COMFAA 3.0 Programg g
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COMFAA Input
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COMFAA DemonstrationDecember 8, 2010
Aircraft Window – COMFAA Inputp
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COMFAA DemonstrationDecember 8, 2010
Main Window - COMFAA Inputp
Click “PCN Flexible Batch”PCN Flexible Batch
Click “CBR” – Enter Enter the evaluation 9.0 in the dialog box. thickness = 33.8 in.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Outputp
Click “Details” to view the detailed outputthe detailed output.
Message “Flexible Computation Finished”
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COMFAA DemonstrationDecember 8, 2010
COMFAA Detailed Output Screenp
Summary Aircraft Table ith 6D Thi kwith -6D Thickness Requirements
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COMFAA DemonstrationDecember 8, 2010
COMFAA Output – Details (I)p ( )
COMFAA t i ft ACN t blCOMFAA generates an aircraft ACN table. CBR 9 indicates B subgrade designation.
PCN based on using aircraft ACN can be reported as• PCN based on using aircraft ACN can be reported as 54.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Output – Details (II)p ( )COMFAA generates a table based on the CDF method. For each
CBR 9 indicates B subgrade designation
aircraft, allowable gross weight and corresponding PCN are identified.
subgrade designation.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Output – Details (III)p ( )
• CDF method identifies (3) aircraft that contribute b t ti l t t l d b d tsubstantial structural damage based on pavement
structure: 727-200, 747-400, and A300-B4.
PCN based on technical CDF method can be• PCN based on technical CDF method can be reported as the highest PCN of these aircraft = 73.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Detailed Output Screenp
Copy and paste data intoCopy and paste data into COMFAA support
spreadsheet.spreadsheet.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support Spreadsheetpp p
Data ParseData Parse• Copy/Paste output
data into Cell B5
• Click “Create Flexible Pavement Charts”
• Airplanes are ordered by PCN number, with the aircraft at top giving the highest PCN when treated as critical.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetFl ibl Ch tFlexible Charts
Thickness
AC 150/5335-5B Example
Most Demanding Aircraft in Traffic Mix1,200
nds)
Thickness Comparison
• Compare20 in
25 in.
30 in.
35 in.g
nt T
hick
ness
600
800
1,000
ght,
lbs.
(th
ousa
n
Compare thickness and gross weights.
• When CDF5 in.
10 in.
15 in.
20 in.
Rig
id P
avem
en
200
400
600
plan
e G
ross
Wei
g
When CDF thickness (yellow) is less than evaluation
0 in. 0 Airp
1. 6D thickness at traffic mixGW
25.7 25.7 25.5 27.5 28.8 23.1
767-200 ER
DC8-63 777-200 A300-B4 747-400 727-200
``̀
thickness (red), excess PCN is available.
2. CDF thickness at max.GW
33.2 31.4 31.9 29.5 29.3 27.5
3. Evaluation thickness fromequivalent pavement
33.8 33.8 33.8 33.8 33.8 33.8
4 Max Allowable Aircraft 378 158 365 739 646 354 443 728 992 902 253 830 4. Max.Allowable AircraftGW from CDF
378,158 365,739 646,354 443,728 992,902 253,830
5. Aircraft GW from trafficmix
370,000 330,000 600,000 370,000 820,000 185,000
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetFl ibl Ch tFlexible Charts
PCN
AC 150/5335-5B Example
PCN= 90 Most Demanding Aircraft in Traffic Mix3,500
PCN Comparison
• PCN needed for57 57
68 7173
PCN= 60
PCN= 70
PCN= 80
9.0,
t=
33.
8
2,500
3,000
es PCN needed for using traffic is 54.
• PCN based on CDF analysis can
4549
51 52 54
4847
57 57
PCN= 40
PCN= 50
PCN= 60
de=
B a
t C
BR
= 9
1,500
2,000
Ann
ual D
epar
ture
CDF analysis can be reported as high as 73.
PCN= 10
PCN= 20
PCN= 30
Sub
grad
e co
d
500
1,000
A
PCN= 0 0
1. Aircraft ACN at traffic mixGW
45.2 48.8 51.3 52.4 53.9 48.2
767-200 ER
DC8-63 777-200 A300-B4 747-400 727-200
2. Calculated PCN at CDFmax. GW
46.6 56.7 57.0 68.3 70.6 72.8
3. Annual Departures fromtraffic mix
2,000 800 300 1,500 3,000 400
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COMFAA DemonstrationDecember 8, 2010
Technical Method Example – Case 1p
International h b airport• International hub airport.
• Rigid pavement.
• Large number of narrow-body, dual-wheel-gear aircraft.
• Example courtesy of Rodney Joel.
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COMFAA DemonstrationDecember 8, 2010
CASE 1 AIRCRAFTACN gear
Operating Weight, lb
Gear Load. lbs.
Wheel Load, lbs.
Avg Annual Departures
Total Coverages
20 yrs
Traffic Data
DC-9-30/40 D 109000 51775 25888 8 44
B717-200 D 122000 57950 28975 301 1701
A318-100 std D 124500 59138 29569 654 3593
Traffic DataA319-100 std D 142500 67688 33844 13,002 70663
A320-100 D 151000 71725 35863 15,280 79583
MD-80/83/88 D 161000 76475 38238 739 4322
MD-90 D 168500 80038 40019 213 1283
B727-200 basic D 185200 87970 43985 111 760
B737-700 D 188200 89395 44698 18,133 96709
B757-300 2D 271000 128725 32181 10,079 51555
DC-8-60/70 2D 358000 170050 42513 79 472
A300-b4 std 2D 365750 173731 43433 831 4579
B767 300 2D 413000 196175 49044 2 521 14006B767-300 2D 413000 196175 49044 2,521 14006
DC-10 2D 458000 217550 54388 115 622
B787-8 2D 478000 227050 56763 32 169
A330-200 std 2D 509000 241775 60444 88 936A330-200 std 2D 509000 241775 60444 88 936
A340-300 std 2D 608000 243200 60800 179 1884
MD-11 2D 633000 245288 61322 44 240
B747-400 2D 877000 208288 52072 754 4358
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B747 400 2D 877000 208288 52072 754 4358
A380 (2D) 2D 1235000 469300 117325 59 309
B777-200 base 3D 537000 255075 42513 1,095 5153
CASE 1
E istingExisting Pavement Data
17″ PCC, R = 775 psi
Effective k at top of base = 323 psi/in
Data, p
8″ CTB
k-value = 160 psi/in
The original design based on procedures in AC 150/5320-6D called for 16.3 inches of PCC. This value was rounded to 17.0 inches.
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COMFAA DemonstrationDecember 8, 2010
CASE 1 AIRCRAFTACN gear
Operating Weight (lb)
Annual Departures
-6D Edge Load Thickness (in)
PCA Design Thickness (in)
DC-9-30/40 D 109000 8 8 04 7 24
Pavement thickness requirements based
DC-9-30/40 D 109000 8 8.04 7.24
B717-200 D 122000 301 9.66 8.65
A318-100 std D 124500 654 9.23 8.18
A319-100 std D 142500 13 002 12 17 10 14
on actual annual departures:
A319 100 std D 142500 13,002 12.17 10.14
A320-100 D 151000 15,280 12.98 10.73
MD-80/83/88 D 161000 739 11.67 10.46
MD-90 D 168500 213 11.49 10.27
•FAA AC 150/5320-6D
•PCA method
B727-200 basic D 185200 111 10.92 9.81
B737-700 D 188200 18,133 15.47 12.71
B757-300 2D 271000 10,079 10.85 10.31
• B737-700 appears to be the “design”
DC-8-60/70 2D 358000 79 10.05 9.72
A300-b4 std 2D 365750 831 10.78 10.62
B767-300 2D 413000 2,521 11.62 11.26be the design airplane based on 5335-5A procedures.
• B737-700 is comprised
DC-10 2D 458000 115 9.52 9.21
B787-8 2D 478000 32 10.57 10.1
A330-200 std 2D 509000 88 10.84 10.28B737-700 is comprised of several D gear airplanes.
A340-300 std 2D 608000 179 10.99 10.45
MD-11 2D 633000 44 10.65 10.27
B747-400 2D 877000 754 11.17 11.07
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COMFAA DemonstrationDecember 8, 2010
A380 (2D) 2D 1235000 59 10.60 10.13
B777-200 base 3D 537000 1,095 8.85 9.46
CASE 1 – Current Procedure
• Following 5335-5A procedures the B737-700 g pwould become the “Critical Aircraft” due to its individual pavement thickness prequirement.
• This is true for either the 5320-6D procedureThis is true for either the 5320 6D procedure or the PCA center slab procedure.
• It was speculated that the B737 was• It was speculated that the B737 was artificially elevated as the design airplane due to high departure levels caused bydue to high departure levels caused by lumping several D-gear airplanes into one.
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COMFAA DemonstrationDecember 8, 2010
CASE 1 AIRPLANEACN gear
Allowable Operating
Weight
Equiv.Annual
Departures5335-5A PCN/R/B
DC-9-30/40 D 148600 739535 45.4
A318-100 std D 181000 345027 46.1
B717-200 D 158900 386168 50.1
A319-100 std D 189250 168314 52 1• PCN values calculated A319-100 std D 189250 168314 52.1
A320-100 D 189500 125753 55.2
B737-700 D 201400 45167 59.8
MD-80/83/88 D 184000 92089 60.1
• PCN values calculated by following the procedures in AC 150/5335 5A d MD-90 D 189100 74317 61.4
B727-200 basic D 222200 48463 65.7
B757-300 2D 385300 130968 68.7
A300-b4 std 2D 481000 32997 84 9
150/5335-5A and assuming that each airplane is the “design
A300-b4 std 2D 481000 32997 84.9
DC-8-60/70 2D 457500 36135 85.6
B767-300 2D 553000 20131 87.3
A330-200 std 2D 672000 9296 89.3
airplane.”
• In this mix, the B737-700 is comprised of
A340-300 std 2D 806000 10907 90.1
A380 (2D) 2D 1568000 20322 92.0
B747-400 2D 1148000 15972 92.8
DC-10 2D 653600 13572 93 0
700 is comprised of several D gear airplanes, some with lower operating DC-10 2D 653600 13572 93.0
B787-8 2D 608500 11612 96.4
MD-11 2D 820500 9462 100.6
B777-200 base 3D 920500 23190 115.2
lower operating weights.
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COMFAA DemonstrationDecember 8, 2010
CASE 1 AIRPLANE
Gear type for
ACNOperating
WeightAirplane ACN/R/B
ACN values for each
AIRPLANE ACN Weight ACN/R/B
A318-100 std D 124500 29.5
DC-9-30/40 D 109000 31.3
B717-200 D 122000 36.5ACN values for each airplane (from COMFAA)
oper
ate
ion
A319-100 std D 142500 37.2
B757-300 2D 271000 41.4
A320-100 D 151000 42.2
B777-200 baseline 3D 537000 47.4
nes
can
out
res
tric
tiB777 200 baseline 3D 537000 47.4
MD-80/83/88 D 161000 51.3
B727-200 basic D 185200 52.7
MD-90 D 168500 53.5
Assuming the B737-700 as the design airplane per the procedures in
Airp
lan
with
ouB737-700 D 188200 55.2
DC-10 2D 458000 56.4
A300-b4 std 2D 365750 57.3
B767-300 2D 413000 57.4per the procedures in 5335-5A
Calculated PCN 59 8/R/B ht
tio
ns
DC-8-60/70 2D 358000 60
A330-200 std 2D 509000 61.2
A340-300 std 2D 608000 61.4
59.8/R/BPCN = (60/R/B)
Wei
gR
estr
ict
B747-400 2D 877000 63
A380 (2D) 2D 1235000 65.8
B787-8 2D 478000 68.3
MD-11 2D 633000 69.6
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COMFAA DemonstrationDecember 8, 2010
Case 1 – New CDF PCN Procedure
• The procedure for finding equivalentThe procedure for finding equivalent coverages in AC 150/5335-5A is based on gear equivalency factors and the ratio ofgear equivalency factors and the ratio of wheel loads.
• An alternative procedure based on• An alternative procedure based on cumulative damage factors (CDF) gave more consistent and rational resultsmore consistent, and rational, results.
• The new procedure for finding equivalent h b i t d i thcoverages has been incorporated in the new
AC 150/5335-5B.
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COMFAA DemonstrationDecember 8, 2010
COMFAA 3.0 – Case 1
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support Spreadsheetpp p
Rigid Pavement k ValueRigid Pavement k-Value
– Each subbase layer contributes to an improved subgrade support k valuesubgrade support k-value.
– ENTER all existing pavement layers.
– ENTER the flexural strength of the concrete and the subgrade support k-value.
– The spreadsheet updates the graphical representation of the existing and equivalent pavement.
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COMFAA DemonstrationDecember 8, 2010
COMFAA 3.0 – Aircraft Window
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COMFAA DemonstrationDecember 8, 2010
COMFAA 3.0 – Case 1 ResultsSubgrade Category B
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COMFAA DemonstrationDecember 8, 2010
COMFAA 3.0 – Case 1 Results
Copy and Paste Data into Support SpreadsheetSupport Spreadsheet
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetC 1Case 1
Data ParseData Parse• Copy/Paste output
data into Cell B5
• Click “Create Rigid Pavement Charts”
• Airplanes are pordered by PCN number, with the aircraft at top giving p g gthe highest PCN when treated as critical.
• Next, click Rigid Chart tab.
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetRi id Ch t C 1Rigid Charts – Case 1
ThicknessAC 150/5335-5B Example
1,800 Thickness Comparison
• Compare12 in.
14 in.
16 in.
18 in. Most Demanding Aircraft in Traffic Mix
hick
ness
1,200
1,400
1,600
1,800
bs.
(tho
usan
ds)
Compare thickness and gross weights.
• When CDF4 i
6 in.
8 in.
10 in.
12 in.
Rig
id P
avem
ent
Th
400
600
800
1,000
e G
ross
Wei
ght,
lb
`` When CDF thickness (yellow) is less than evaluation
0 in.
2 in.
4 in.R
0
200
400
Airp
lane
B747-400A330-200
stdA340-300
stdA380-Wing
B787-8 (Preliminar
y)MD11
thickness (red), excess PCN is available.
1. 6D thickness at traffic mixGW
11.1 10.8 11.1 10.6 10.5 10.6
2. CDF thickness at max. GW 15.0 15.0 15.0 15.0 14.9 14.9
3. Evaluation thickness fromi l t t
17.0 17.0 17.0 17.0 17.0 17.0
y)
equivalent pavement
4. Max.Allowable Aircraft GWfrom CDF
1,076,982 657,683 785,764 1,558,981 590,004 792,982
5. Aircraft GW from traffic mix 877,000 509,000 608,000 1,235,000 478,000 633,000
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetRi id Ch t C 1Rigid Charts – Case 1
PCN
AC 150/5335-5B Example
PCN= 110 Most Demanding Aircraft in Traffic Mix800
PCN Comparison
• 6 most demanding63 66 68 70
85 87 8791 92
96
PCN= 70
PCN= 80
PCN= 90
PCN= 100
PCN 110 Most Demanding Aircraft in Traffic Mix
.0,
t= 1
7.0
500
600
700
ures 6 most demanding
aircraft in mix.
• PCN needed for using traffic is 70
63 61 6166
PCN 30
PCN= 40
PCN= 50
PCN= 60
PCN= 70
ade
code
= B
323
300
400
Ann
ual D
epar
tu
using traffic is 70.
• PCN based on CDF analysis can be reported as
PCN= 0
PCN= 10
PCN= 20
PCN= 30
Sub
gra
0
100
200
A330 200 A340 300 A380B787-8 be reported as
high as 96.
• Next, click on Form 5010 tab
1. Aircraft ACN at traffic mixGW
63.0 61.2 61.4 65.8 68.3 69.6
2. Calculated PCN at CDF 84.6 86.6 87.0 91.2 92.2 95.8
B747-400A330-200
stdA340-300
stdA380-Wing
(Preliminary)
MD11
Form 5010 tab. 2. Calculated PCN at CDFmax. GW
84.6 86.6 87.0 91.2 92.2 95.8
3. Annual Departures fromtraffic mix
754 88 179 59 32 44
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COMFAA DemonstrationDecember 8, 2010
COMFAA Support SpreadsheetRi id Ch t C 1Rigid Charts – Case 1
Form 5010
Project info
Form 5010 • Enter PCN Number.
• PCN can be reported as:
FLEXIBLE PAVEMENT MAXIMUM TIRE PRESSURE METHOD USED TO DETERMINE PCN
A Subgrade Category (CBR 15)
B Subgrade Category (CBR 10)
C Subgrade Category (CBR 6)
Using Aircraft
Technical
W Unlimited
X 218 psi
Y 145 psi
Z 73 psi p
96/R/B/W/T RIGID PAVEMENT AIRCRAFT GEAR TYPE IN TRAFFIC MIX
S (single wheel gear)
D (dual wheel gear)
D Subgrade Category (CBR 3)
A Subgrade Category (k 552 pci)
B Subgrade Category (k 295 pci)
Z 73 psi
96Enter PCN
2D OR 3D (dual tandem OR triple tandem wheel gear)
W/B (tandem gear under wing AND tandem gear under body)
B Subgrade Category (k 295 pci)
C Subgrade Category (k 147 pci)
D Subgrade Category (k 74 pci)
FAA Form 5010 Data Element
Gross Weight and PCN
#35 S 100
96Enter PCN
#36 D 280#37 DT 793
#38 DDT#39 PCN 96 / R / B / W / T
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COMFAA DemonstrationDecember 8, 2010
Case 1 – PCN ComparisonPCN l l t d i h i l i t t d th d i i lPCN calculated assuming each airplane is treated as the design airplane
120
D Gears 2D Gears
80
100
60
80
N o
r A
CN
40
PC
N
5335-5A PCN/R/B
A380B747
B777
20
5335 5A PCN/R/B
5335-5B PCN/R/B
Airplane ACN/R/B
B777B757
00 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000
Reported Operating Weight, lbs. (not the weight used for PCN calculation)
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COMFAA DemonstrationDecember 8, 2010
COMFAA 3.0 – Optionsp
• Batch• Batch– Runs all airplanes in
succession.
– Automatically invoked by PCN Flex and Rigid Batch function.
• Metric
• PCA Thick– Equivalent coverages
computed with the PCAcomputed with the PCA interior stress design method.
• PCA GW– Maximum gross weight
computed with the PCA interior stress design method.
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COMFAA DemonstrationDecember 8, 2010
COMFAA 3.0 – Computational Modesp
• ACN C t ACN t• ACN – Computes ACN at indicated gross weight & strength.
• PCN – Computes PCN using p gCDF-based procedure.
• Thickness – Computes by AC 150/5320 6D d150/5320-6D procedure.
• MGW – Computes maximum gross weight for airplane.g g p
• Life – Computes coverages to failure for indicated thickness.
• Interior Stress
• Edge Stress
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COMFAA DemonstrationDecember 8, 2010
COMFAA 2.0 Will Continue to be S t d Si l d Old Al hSupported – Simpler and Old Alphas
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COMFAA DemonstrationDecember 8, 2010
More Information
Contact Dr Gordon Ha hoe• Contact Dr. Gordon Hayhoe– [email protected]
• FAA Airport Technology R&D Group– www.airporttech.tc.faa.gov
– Click on “Downloads” then “Pavements”
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Questions?
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COMFAA DemonstrationDecember 8, 2010