Safer Skies - Uncontained Safer Skies - Uncontained Engine FailuresEngine Failures

Orlando FSDO Corporate Seminar - August 2002

Ben Coleman, ASO-FSDO-15Aviation Safety Program,Southern RegionFlight Standards Service

Our special thanks to:Our special thanks to:

Mark Liptak & Ann Azevedo Engine & Propeller Standards Staff

ANE-110Engine & Propeller Directorate

FAA Aircraft Certification ServiceBurlington, Mass.

AgendaAgenda Safer Skies Background & Overview Commercial Fleet Growth Projections Engine Accident/Incident Information UEF Intervention Actions Summary

In the U.S. our focus is set by theIn the U.S. our focus is set by theWhite House Commission on White House Commission on

Aviation SafetyAviation Safety1.1 Government and industry

should establish a national goal to reduce the aviation fatal accident rate by a factor of five within ten years and conduct safety research to support that goal.

1.2 The FAA should develop standards for continuous safety improvement, and should target its regulatory resources based on performance against those standards

5.3-2

White House CommissionWhite House CommissionRecommendationsRecommendations

Five-Fold Accident Reduction

Partnership with NASA and the aviation industry

Develop and share safety data and analysis tools

The National Civil Aviation Review The National Civil Aviation Review Commission (NCARC) Commission (NCARC)

on Aviation Safety Provided Additional Directionon Aviation Safety Provided Additional Direction

• FAA and the aviation industry must develop a strategic plan to improve safety, with specific priorities based on objective, quantitative analysis of safety information and data. And….

5.3-3

The National Civil Aviation Review The National Civil Aviation Review Commission (NCARC) Commission (NCARC)

on Aviation Safety Provided Additional Directionon Aviation Safety Provided Additional Direction

• Government should expand on their programs to improve aviation safety in other parts of the world.

5.3-3

NCARC RecommendationsNCARC Recommendations80% REDUCTION IN THE COMMERCIAL FATAL

ACCIDENT RATE WITHIN 10 YEARS

FAA and industry prioritize safety agenda and implement a strategic plan

FAA safety programs must become performance based

Government/Industry partnership

Strengthen international activities

HUMAN FACTORSIN OPERATIONS &

MAINTENANCE

Carry-on Baggage

Child Restraint

Passenger Interference

CABIN SAFETY

IMPROVED DATA & ANALYSIS

GENERAL AVIATION

Loss of Control

Weather

Survivability

Pilot Decisionmaking

Controlled Flight Into Terrain

Approach and Landing

COMMERCIAL AVIATION

Controlled Flight Into Terrain

Loss of Control

Weather

Uncontained Engine Failures

Runway Incursion

Passenger Seat Belt Use

Runway Incursions

SAFER SKIES - A FOCUSED AGENDA

Hull Loss Accident Rates by World RegionsHull Loss Accident Rates by World Regionsby Accident Siteby Accident Site

Western-Built Transports, 1988 through 1997

United Statesand Canada

0.5

Latin Americaand Caribbean

4.7

Europe0.8

China2.7

Middle East1.9

Africa9.5

Asia2.3

World1.4

Oceania0.5

Accidents permillion departures

(ExcludingChina)

JAA - 0.6NonJAA - 1.2

C.I.S.*

*Insufficient data to generate reliable rate.

Potential for Totally New Airplane Designsto Affect Safety is Very Small

25,000

20,000

15,000

10,000

5,000

02005 2010 2015

Number ofairplanes Total Airplanes Produced

After 1998

2000

Out of Production Models(as of 1998)

Current Fleet

New Designs

1998 2007

CommitmentCommitmentPrevention of accidents is our

highest priority Resources for critical

interventions–Focus on top safety areas–Ensure full implementation

CornerstoneCornerstone

Commitment of resourcesStandardized, focused

approachPartnerships with aviation

community

What is uncontainment?

• Uncontainment is when internal engineparts have passed completely throughthe nacelle of the engine

• Also of interest are events that arecontained by the nacelle, but penetratethe engine containment case

Relevant Acronyms :Relevant Acronyms :Aerospace Industries

Association (AIA)Continued Airworthiness

Assessment Methodologies (CAAM)

CAAM Event DefinitionsCAAM Event Definitions

Level 4 (Severe Consequences):–Hull loss–Fatal or serious injury–Forced landing

CAAM Event DefinitionsCAAM Event Definitions Level 3 (Serious Consequences):

– Substantial damage to aircraft or unrelated system

– Uncontrolled fire– Rapid depressurization– Temporary or permanent inability to climb/fly 1000 ft above terrain– Temporary or permanent impairment of aircraft controllability

CAAM Event DefinitionsCAAM Event Definitions

Level 2 (Significant Consequences):

–Nicks, dents, minor damage–Controlled fire or slow depres–Minor Injuries–High-speed takeoff abort

CAAM Event DefinitionsCAAM Event Definitions

Level 1 (Minor Consequences):–Uncontained damage

confined to nacelle–Separation, uncommanded

power increase, no loss of control

Causal Factors of Disk FracturesAccident (level 4)

Hazardous events:~ 16 per 100 M flights

All non-contained:~ 32 per 100 M flights

low cyclefatigue

high cyclefatigue

manufact .defect

materialdefect

shopmaint . &overhaul

fretting/rubbing

erosion/corrosion

bearingfailure

overspeed overtemp FOD

ForgingMachiningPeening

TitaniumInconelSteelOther

Unapproved partAssembly errorInspectionRepair

BirdsA/C ice shedBlue iceBMOD

Loss of diskcooling,Limitationexceeded

Shaft failureFuel ControlClosed VSVs

Examples

Opportunity to Inspect

~ 5 per 100 Million Flights

Maintenance Program Part Fractures

Uncontained Engine Failure Uncontained Engine Failure Sioux City Sioux City (July 1989)(July 1989)

DC10-10 crashed on landing

Multiple inspection opportunities before failure

In-flight separation of stage 1 fan disk– Metallurgical processes

over-hardened material– 111 fatalities No. 2 engine stage 1 fan disk (reconstructed with blades).

Uncontained Engine Failure Uncontained Engine Failure Pensacola Pensacola (July 1996)(July 1996)

MD-88 engine failure on take-off roll

Multiple inspection opportunities before failure

Stage 1 fan disk separated; impacted cabin– Failure from abusively

machined bolt-hole– 2 fatalities

Visual Aid -Visual Aid -

Turbofan Engine Malfunction:

Recognition and Response

Disk fractures are the major propulsion system risk

Current rate of hazardous uncontained events is 0.9 every 10 million takeoffs.

Number of uncontained events expected to increase as commercial fleet grows

Considerable crack growth time precedes most disk fractures

Uncontained Engine FailuresUncontained Engine Failures

Prioritized the most safety significant parts and features, linked to the best inspection method

ADs to mandate enhanced inspections of selected safety critical parts/features – instructions in OEM manuals

Multiple waves of AD’s being issued - about 3/4 of commercial fleet affected

Target UEF reduction 40 to 50%

UEF Intervention ActionUEF Intervention Action

SummarySummary

• Data driven intervention actionsData driven intervention actions• Prioritized for max safety benefitPrioritized for max safety benefit• Cooperative effort between FAA and Cooperative effort between FAA and

industryindustry• AD’s to mandate focused inspection AD’s to mandate focused inspection of critical features on safety of critical features on safety

critical partscritical parts

SummarySummary

• fan and HPT AD’s issued -fan and HPT AD’s issued - high compressors and LPT’s being high compressors and LPT’s being worked worked • performance measurements in performance measurements in place place through 2007through 2007

Questions ??Questions ??Answers Answers

http://www.faa.gov/certification/aircraft/

engine_special_topics.htm