|It's fairly well-known
that most accidents are human error related, at least in part. And in aviation,
because pilots are always first to arrive at the scene of an accident, it
is generally a maxim that to some degree, pilot error is normally involved
- to some degree. It may not necessarily be the primary cause but it could
be that a pilot team failed to cope with the circumstances that they were
suddenly handed. On the other hand, one is not to know whether (or to what
degree) their mount let them down. We rarely hear much about the success
stories when a pilot does manage to accommodate a systems or hardware failure
and retrieve the situation. And then of course there are the circumstances
where a scenario is complicated by weather, fuel shortages, pilot fatigue,
terrorism, passenger rage or inexperience.
But what about Maintenance Error? Since the end of the Cold War the pool of Air Force trained technicians around the World has dried up and expertise is becoming a little harder to come by. To what degree will Maintenance Error become a more significant factor in the future? And when it is a materiel failure such as faulty (or deficient) wiring, will it ever be apparent? Is that designated maint error or designer error? Or is there (should there be?) another category of error? Perhaps we could call it regulatory error.
Judge for yourself by visiting some of these links (including the FAA's below)...... and by looking at a selection of past maintenance related mishaps.
a few other suggestions
http://www.aaib.dft.gov.uk/bulletin/aug02/n7375A.htm (767 version of repeat Nov 96 A320 losses)
http://www.aaib.dft.gov.uk/bulletin/jul00/gvced.htm A320 engine doors falling off
"The Royal Flight BAe146 loss of oil from all four engines" (fsa43%2D44.pdf )
Major Mayhem from Maintenance Mistakes
The toll in aircraft and people (a partial listing):
The tally: 2,400 killed, 90 injured. Insurance losses of $1.825 million at the time in hull and passenger (pax)/third party settlements. Does not include uninsured losses. Insurance losses would be far greater if these events happened today due to significant increases in liability settlements over the years.
ñ May 25, 2002. China Airlines B747-200. Structural failure at top of climb to cruise altitude. Crash into Taiwan Strait. Repair of previous tailstrike used steel doubler, prohibited by structural repair manual. Preliminary findings suggest shortcomings in supplemental structural integrity program (SSIP) to assure airworthiness of high-time aircraft. Toll: 225 killed.
ñ Aug. 24, 2001. Air Transat A330. Improper engine repair; resulting leak from cracked fuel line caused duel engine flameout at cruise over Atlantic. Glided 135 miles to emergency landing in Azores. No serious injuries.
ñ April 26, 2001. Emery Worldwide Airlines DC-8-71F. Left main landing gear would not extend for landing. Probable cause was failure of maintenance to install the correct hydraulic landing gear extension component and the failure of inspection to comply with post-maintenance test procedures. No injuries.
ñ March 20, 2001. Lufthansa A320. Cross-connected pins reversed the polarity of captain’s side stick. Post-maintenance functional checks failed to detect the crossed connection. Aircraft ended up in 21º left bank, almost hitting the ground. Co-pilot switched his side-stick to priority and recovered the aircraft. No injuries.
ñ Jan 21, 2001. Emirates B777. Uncontained engine failure during takeoff caused by loss of one of 26 low-pressure compressor blades. Incident led to shortened inspection intervals, need for more attention to dry lubricant application and bade redesign. No serious injuries.
ñ July 25, 2000. Air France Concorde. During takeoff the front right tire of left landing gear ran over a strip of metal, which had fallen off preceding DC-10, causing tire blowout, loss of two left engines and fire. Spacer improperly installed in left gear of Concorde. Toll: 109 pax and crew, plus 4 killed and 6 injured on ground.
ñ Feb. 16, 2000. Emery Worldwide Airlines DC-8-71F. Crashed attempting to return to Rancho Cordova, Calif. Right elevator control improperly installed. Toll: 3 crew killed.
ñ Jan. 31, 2000. Alaska Airlines MD-83. Crashed in Pacific Ocean near Port Hueneme due to loss of horizontal stabilizer believed to have been aggravated by failure to lubricate jackscrew assembly controlling pitch trim. Toll: all 88 aboard killed.
ñ Dec. 18, 1999. Ugandan Air Carrier DC-10-30F. Uncontained blade separation in No. 2 center engine during takeoff from Amsterdam. No injuries.
ñ Nov. 1, 1998. AirTran Airways, B737-200. Loss of hydraulic pressure during climb out and returned for landing. No injuries.
ñ Oct. 7, 1998. Continental Airlines B727. Catastrophic failure of the 8th stage high-pressure compressor disk from cadmium embrittlement as a result of improper adherence to prescribed procedures. No injuries.
ñ Aug. 7, 1997. Fine Air DC-8-61F. Crashed on takeoff at Miami. Aircraft was improperly loaded, creating aft center of gravity and corresponding incorrect stabilizer trim setting. Pilots unable to counter extreme pitch-up on rotation. Toll: 5 killed.
ñ May 21, 1998. Continental Airlines, DC-10-10. Autopilot malfunction caused the aircraft to begin a sudden uncommanded 2G pull-up, with the control yoke moving rapidly to the left. The cause was a contaminated strain gage, which resulted in excess elevator actuation during recovery by the captain. Toll: 3 crew and 1 pax seriously injured.
ñ Jan 21, 1998. Continental Express ATR-42. Fire in right engine during landing, due to improper overhaul of lugholes in the fuel/oil heat exchanger. No serious injuries.
ñ June 7, 1997. Continental Airlines, B727. Unqualified maintenance employee drove aircraft into the terminal. No injuries.
ñ Sept. 27, 1997. Continental Airlines B737. Separation of aileron bus cable forced the crew to return to the airport shortly after takeoff. Separation was caused by wear in the cable and inadequate inspection of same. No serious injuries.
ñ March 18, 1997. Continental Airlines DC-9-32. Failure of maintenance p0ersonnel to perform a proper inspection of the combustion chamber outer case, allowing a detectable crack to grow to a length at which the case ruptured, causing uncontained failure of right engine. No injuries.
ñ Dec. 22, 1996. Airborne Express DC-8-63F. Struck mountainous terrain. Contributing to the accident was the inoperative stick shaker stall warning system. Toll: all 6 on board killed.
ñ Nov. 1996. A320 (operator unknown). Both fan cowl doors detached from No. 1 engine during rotation. Doors likely had been closed but not latched during maintenance. According to AAIB, “Similar incidents have occurred on at least seven other occasions.”
ñ July 17, 1996. TWA Flight 800, B747. Fuel/air explosion due to inadequate maintenance on an aging fleet and noncompliant parts. Toll: all 230 pax and crew killed.
ñ July 6, 1996. Delta Air Lines MD-88. Uncontained engine failure on takeoff due to inadequate parts cleaning, drying, drying, processing and handling. Toll: 2 pax killed, 2 pax seriously injured.
ñ May 11, 1996. ValuJet Airlines DC-9-32. Fire in cargo compartment initiated by actuation of one or more improperly packaged and stowed oxygen generators. Toll: all 110 pax and crew killed.
ñ Feb. 22, 1996. Million Air B707. Lost all hydraulic fluid from utility hydraulic system. Related to the incident was fatigue failure of the utility hydraulic system relief valve, which resulted in an inoperative normal gear extension system.
ñ Aug. 21, 1995. Atlantic Southeast Airlines EMB-120. In-flight fatigue fracture and separation of propeller blade. Toll: 8 pax and 1 crew killed, 10 pax and 2 crew seriously injured.
ñ June 8, 1995. ValuJet Airlines DC-9-32. Maintenance technicians failed to perform a proper inspection of the 7th stage high compression disk, allowing a detectable crack to grow to a length at which it ruptured. Toll: 1 crew seriously injured.
ñ May 13, 1995. United Parcel Service DC-8-71F. Right main landing gear failed on touchdown. No injuries.
ñ Feb. 1995. British Midland B737-400. Oil pressure lost on both engines. Covers had not been replaced from borescope inspection the previous night, resulting in loss of almost all oil from both engines during flight. Diverted and landed safely. No injuries.
ñ March 1, 1994. Northwest Airlines B747. Narita, lower forward engine cowling ground away as dragged along runway. During maintenance, the No. 1 pylon diagonal brace primary retainer had been removed but not reinstalled. No injuries
ñ Aug. 1993. Excalibur Airways A320. Uncommanded roll in first flight after flap change. Returned to land safely at Gatwick. Lack of adequate briefing on status of spoilers (in maintenance mode) during shift change. Locked spoiler not detected during standard pilot functional checks. No injuries.
ñ March 15, 1993. Continental Airlines, B737. Left down aileron cable broke on takeoff, causing the pilot to return for emergency landing. No injuries.
ñ Sept. 11, 1991. Continental Express Airlines, EMB-120. Horizontal stabilizer separated from fuselage during flight because maintenance personnel failed to install 47 screw fasteners. Toll: all 14 pax and crew killed.
ñ July 11, 1991. Nation Air DC-8-61. During takeoff, tires and wheels failed on left main undercarriage. Fire developed in main wheel well causing loss of hydraulics and loss of control. Toll: all 261 pax and crew killed.
ñMay 26, 1991. Lauda Air B767. Uncommanded deployment of thrust reverser in climb out from Bangkok led to loss of control and fatal dive. Numerous thrust reverser fault messages in weeks preceding accident flight. According to Thai accident report, the carrier “did not seek assistance from Boeing or Boeing’s Vienna based field service representative. Boeing considers these removals and interchanges as … ineffective in resolving the cause of the [fault] messages, and not per FIM (fault isolation manual) direction.” Accident triggered modifications to thrust reverser. Toll: 223 pax and crew killed.
ñ Aug. 21, 1990. United Airlines B737. Flashlight left by maintenance, sandwiched between cargo floor and landing gear retract/extend linkage, causing the crew to make a gear up landing. Toll: No injuries.
ñ July 22, 1990. USAir B737. Fuel pump control failure due to improper machining. No injuries.
ñ June 1990. British Airways BAC1-11. Captain sucked halfway out of windscreen. Windscreen blew out under effects of cabin pressure; 84 of 90 securing bolts were smaller than the specified diameter. Toll: 1 serious injury.
ñ July 19, 1989. United Airlines DC-10-10. Catastrophic failure of No. 2 tail mounted engine during cruise. Airplane broke apart and burst into fireball during attempted emergency landing at Sioux City, Iowa, without hydraulic power. Toll: 111 pax and crew killed, 46 pax and crew seriously injured.
ñ Feb. 24, 1989. United Airlines B747. Explosive decompression of cargo door. Toll: 9 pax killed, 2 pax and 3 crew seriously injured.
ñ April 28, 1988. Aloha Airlines B737. Explosive decompression; inadequate inspection/repair of lap joint. Toll: 1 cabin attendant killed, 7 pax and 1 crew seriously injured.
ñ April 8, 1986. United Airlines B737. Left main landing gear collapsed moments after touchdown due to fatigue and lack of regard by maintenance for procedures and directives. No injuries.
ñ Aug. 12, 1985. Japan Air Lines B-747SR. Improper repair of aft pressure bulkhead led to sudden decompression in flight that damaged hydraulic systems and vertical fin. Aircraft struck Mt. Ogura. Toll: 520 pax and crew killed; 4 surviving pax injured.
ñ May 28, 1985. American Airlines DC-10-10. Forward portion of cowl on No. 3 engine separated in flight, striking leading edge of wing, then puncturing fuselage causing a rapid decompression. Toll: ?????? SEE BELOW
ñ May 1983. Eastern Airlines L-1011. Loss of all power from improperly fitted O-ring seals Aircraft landed on one engine. No injuries.
ñ May 25, 1979. American Airlines, DC-10. Separation of No. 1 engine and pylon assembly on takeoff at Chicago’s O’Hare. Toll: all 298 pax and crew plus 2 killed and 2 seriously injured on the ground.
Sources: NTSB, CAA, Airclaims
File: ASW 12 Aug 02 draft
NTSB Identification: NYC85FA138 For details, refer to NTSB microfiche number 32001A
Scheduled 14 CFR 121 operation of AMERICAN AIRLINES
Accident occurred MAY-28-85 at JAMAICA, NY
THE FORWARD ONE-THIRD PORTION OF THE CORE COWL DOOR ON NO. 3 ENGINE SEPARATED IN FLIGHT FIRST STRIKING THE LEADING EDGE OF THE RIGHT WING, THEN PUNCTURING THE FUSELAGE. CAUSING RAPID DECOMPRESSION AT FL 170. THE CORE COWL DOOR LATCHES WERE NOT ADJUSTED & CORE COWL DOOR SHEAR PINS WERE NOT INSTALLED PER MCDONNELL DOUGLAS SERVICE BULLETIN NO. 71-86. DATED MAY 12, 1985.