330 likes | 489 Views
Safer Skies - Uncontained Engine Failures. Orlando FSDO Corporate Seminar - August 2002. Ben Coleman, ASO-FSDO-15 Aviation Safety Program, Southern Region Flight Standards Service. Our special thanks to:. Mark Liptak & Ann Azevedo Engine & Propeller Standards Staff ANE-110
E N D
Safer Skies - Uncontained Engine Failures Orlando FSDO Corporate Seminar - August 2002 Ben Coleman, ASO-FSDO-15 Aviation Safety Program, Southern Region Flight Standards Service
Our special thanks to: Mark Liptak & Ann Azevedo Engine & Propeller Standards Staff ANE-110 Engine & Propeller Directorate FAA Aircraft Certification Service Burlington, Mass.
Agenda • 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 theWhite House Commission on Aviation Safety 1.1 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 CommissionRecommendations Five-Fold Accident Reduction • Partnership with NASA and the aviation industry • Develop and share safety data and analysis tools
The National Civil Aviation Review Commission (NCARC) on 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 Commission (NCARC) on 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 Recommendations 80% 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
Hull Loss Accident Rates by World Regionsby Accident Site Western-Built Transports, 1988 through 1997 C.I.S.* Europe 0.8 United States and Canada 0.5 JAA - 0.6 NonJAA - 1.2 China 2.7 Asia 2.3 Middle East 1.9 (Excluding China) Africa 9.5 Latin America and Caribbean 4.7 Accidents per million departures Oceania 0.5 World 1.4 *Insufficient data to generate reliable rate.
Potential for Totally New Airplane Designs to Affect Safety is Very Small 25,000 New Designs 20,000 Number of airplanes Total Airplanes Produced After 1998 15,000 10,000 Current Fleet 5,000 Out of Production Models (as of 1998) 0 1998 2000 2005 2007 2010 2015
Commitment • Prevention of accidents is our highest priority • Resources for critical interventions • Focus on top safety areas • Ensure full implementation
Cornerstone • Commitment of resources • Standardized, focused approach • Partnerships with aviation community
Relevant Acronyms : Aerospace Industries Association (AIA) Continued Airworthiness Assessment Methodologies (CAAM)
CAAM Event Definitions • Level 4 (Severe Consequences): • Hull loss • Fatal or serious injury • Forced landing
CAAM 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 Definitions • Level 2 (Significant Consequences): • Nicks, dents, minor damage • Controlled fire or slow depres • Minor Injuries • High-speed takeoff abort
CAAM Event Definitions • Level 1 (Minor Consequences): • Uncontained damage confined to nacelle • Separation, uncommanded power increase, no loss of control
Causal Factors of Disk Fractures ~ 5 per 100 Million Flights Accident (level 4) Hazardous events: ~ 16 per 100 M flights Part Fractures Maintenance Program All non-contained: ~ 32 per 100 M flights Opportunity to Inspect Examples overspeed low cycle high cycle manufact . material shop fretting/ erosion/ bearing overtemp FOD fatigue fatigue defect defect maint . & rubbing corrosion failure overhaul Birds Shaft failure Loss of disk Forging Titanium Unapproved part A/C ice shed Fuel Control cooling, Machining Inconel Assembly error Blue ice Closed VSVs Limitation Peening Steel Inspection BMOD exceeded Other Repair
Uncontained Engine Failure Sioux City (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 Pensacola (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 - Turbofan Engine Malfunction: Recognition and Response
Uncontained Engine Failures • 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
UEF Intervention Action 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%
Summary • Data driven intervention actions • Prioritized for max safety benefit • Cooperative effort between FAA and industry • AD’s to mandate focused inspection of critical features on safety critical parts
Summary • fan and HPT AD’s issued - • high compressors and LPT’s being • worked • performance measurements in place • through 2007
Questions ?? Answers http://www.faa.gov/ certification/aircraft/ engine_special_topics.htm