List of maintenance-related failures

This list of maintenance-related failures is a listing of incidents and accidents that have been, partially or completely, caused by human errors in aircraft maintenance.

Incidents

Eastern Air Lines Flight 855

Main wikipage: Eastern Air Lines Flight 855

At 08:56 on May 5, 1983, Eastern Air Lines, Inc., Flight 855, a Lockheed L-1011, with 10 crewmembers and 162 passengers on board, departed Miami International Airport en route to Nassau, Bahamas.

About 09:15, while descending through 15,000 feet, the low oil pressure light on the No. 2 engine illuminated. The No. 2 engine was shut down, and the captain decided to return to Miami to land. The airplane was cleared to Miami and began a climb to FL 200. While en route to Miami, the low oil pressure lights for engines Nos. 1 and 3 illuminated.

At 09:28, while at 16,000 feet, the No. 3 engine flamed out. At 0933:20, the No. 1 engine flamed out while the flightcrew was attempting to restart the No. 2 engine. The airplane descended without power from about 13,000 feet to about 4,000 feet, at which time the No. 2 engine was restarted.

The airplane made a one-engine landing at Miami International Airport at 09:46. There were no injuries to the occupants.

The National Transportation Safety Board determines that the probable cause of the accident was the omission of all the O-ring seals on the master chip detector assemblies leading to the loss of lubrication and damage to the airplane's three engines as a result of the failure of mechanics to follow the established and proper procedures for the installation of master chip detectors in the engine lubrication system, the repeated failure of supervisory personnel to require mechanics to comply strictly with the prescribed installation procedures, and the failure of Eastern Air Lines management to assess adequately the significance of similar previous occurrences and to act effectively to institute corrective action.

Contributing to the cause of the accident was the failure of Federal Aviation Administration maintenance inspectors to assess the significance of the incidents involving master chip detectors and to take effective surveillance and enforcement measures to prevent the recurrence of the incidents.

The FAA report is published on faa.gov/about/initiatives

Excalibur Airways Airbus 320

Main wikipage: Excalibur Airways Airbus 320

On August 26, 1993, an Excalibur Airways Airbus 320 took off from London-Gatwick Airport (LGW) and exhibited an undemanded roll to the right on takeoff, a condition which persisted until the aircraft landed back at LGW 37 minutes later. Control of the aircraft required significant left sidestick at all times and the flight control system was degraded by the loss of spoiler control.

Technicians familiar with Boeing 757 flap change procedures lacked the knowledge required to correctly lock out the spoilers on the Airbus during the flap change work that was done the day before the flight. Turnover to technicians on the next shift compounded the problem. No mention of incorrect spoiler lockout procedure was given since it was assumed that the 320 was like the 757. The flap change was operationally checked, but the spoiler remained locked out incorrectly and was not detected by the flight crew during standard functional checks.

Lufthansa Airbus A320

Main wikipage: Lufthansa Airbus A320

On March 20, 2001 a Lufthansa Airbus A320 almost crashed shortly after takeoff because of reversed wiring in the captain's sidestick flight control. Quick action by the co-pilot, whose sidestick was not faulty, prevented a crash

The investigation has focused on maintenance on the captain's controls carried out by Lufthansa Technik just before the flight. During the previous flight, a problem with one of the two elevator/aileron computers (ELAC) had occurred. An electrical pin in the connector was found to be damaged and was replaced. It has been confirmed that two pairs of pins inside the connector had accidentally been crossed during the repair. This changed the polarity in the sidestick and the respective control channels "bypassing" the control unit, which might have sensed the error and would have triggered a warning. Clues might have been seen on the electronic centralized aircraft monitor (ECAM) screen during the flight control checks, but often pilots only check for a deflection indication, not the direction. Before the aircraft left the hangar, a flight control check was performed by the mechanic, but only using the first officer's sidestick.

Accidents

American Airlines Flight 191

Main wikipage: American Airlines Flight 191

The worst aviation accident in the United States happened on May 25, 1979. The American Airlines, Inc., Flight 191, a McDonnell-Douglas DC-10-10 aircraft, crashed into an open field about 4,600 ft northwest of the departure end of runway 32R at Chicago-O'Hare International Airport, Illinois.

Eight weeks before the disaster, the last repair of the plane damaged the overhead engine tower installed on the plane. The crash was found to be the result of a shortcut taken by removing the plane's engines for maintenance, cracking an aluminum component which held the engine to the wing.

In order to save more than 200 hours of maintenance time and money, the engine and the "dragon" (Pylon, suspended structure) between the engine and wings removed and put together all night just back, so that in the Pylon and cracks caused by the wing joint area. This was a violation of DC-10-10 design original McDonnell Douglas maintenance procedures.

When the American Airlines Flight 191 took off from O'Hare, the engine fell off the plane and landed on the runway, cutting off the electrical system and spilling hydraulic oil. Because of the airplane design, the pilots couldn't see the wing and didn't realize they were losing liquid oil. While being unaware of the real situation, the pilots carried out the wrong handling procedures. The damaged left has stalled, the plane dived and crashed, killing 273 people on the board and two people on the ground.

It was the fourth fatal crash on the DC-10 since its inception, with 622 people killed in all four DC-10 crashes. The complete report is published on ntsb.gov/investigations. The FAA report is published on faa.gov/about/initiatives

Japan Airlines Flight 123

Main wikipage: Japan Airlines Flight 123

On August 12, 1985, the Japan Airlines Flight 123 suffered mechanical failures 12 minutes into the flight and 32 minutes later crashed into a mountain while killing 15 crew members and 509 passengers on board. Till now, this is the second deadliest disaster in the history of aviation.

The aircraft was involved in a tail strike incident seven years earlier, on 2 June 1978, which damaged the rear bulkhead. However, the repair of the damaged section had not been properly repaired. When replacing the damaged pressure wall plate, a whole joint plate should be used to connect the two panels to be connected and three rows of rivets should be used to fix them, but the maintenance personnel used two discontinuous joint plates, one with one row of rivets and the other with two rows of rivets. This results in a significant increase in stress on the metal skin near the joint and a reduction in resistance to metal fatigue of at least 70%.

The metal used in the repairs can only withstand about 10,000 flights, and the Flight 123 was the 12319th flight after the crash. During the flight several years after maintenance, metal fatigue accumulated in the cabin due to repeated pressurization and decompression. Eventually, the rear bulkhead gave way leads to the failure of all 4 hydraulic systems, which disabled the aircraft's control disabled and, when the aircraft became uncontrollable, led to the disaster.

When the aircraft climbed to about 7,000 meters, the accumulated metal fatigue of the pressure wall panel reached the limit, and it could no longer bear the pressure difference and break. As a result, explosion and decompression occurred in the engine room. High pressure air rushed into the tail, blowing down the vertical tail directly and tearing off the main hydraulic pipeline, which made the pilot unable to control the aircraft normally.

The pilots and engineers on the wrecked plane struggled with the plane for half an hour under the condition of nearly completely out of control, showing great efforts. Instead of failed hydraulic systems, the pilots heroically used the engine accelerations and de-accelerations to direct the plane. However, the huge size of the plane and continuous mountain terrain made their task impossible. After the accident, no investigators and pilots who simulated the situation at that time could fly for half an hour under the same circumstances.

Aloha Airlines Flight 243

Main wikipage: Aloha Airlines Flight 243

On April 28, 1988, at 1346, a Boeing 737-200, N73711, operated by Aloha Airlines Inc., as flight 243, experienced an explosive decompression and structural failure at 24,000 feet, while en route from Hilo, to Honolulu, Hawaii. Approximately 18 feet of the cabin skin and structure aft of the cabin entrance door and above the passenger floorline separated from the airplane during flight. There were 89 passengers and 6 crewmembers on board. One flight attendant was swept overboard during the decompression and died; 7 passengers and 1 flight attendant received serious injuries. The flightcrew performed an emergency descent and landing at Kahului Airport on the Island of Maui.

Failure of the Aloha Airlines maintenance program to detect the presence of significant disbonding and fatigue damage ultimately led to failure of the lap joint at S-10L and the separation of the fuselage upper lobe, which is believed to be the probable cause of the accident.

The cited contributing causes include:

1. The failure of Aloha Airlines management to supervise properly its maintenance force;
2. The failure of the FAA to evaluate properly the Aloha Airlines maintenance program and to assess the airline's inspection and quality control deficiencies;
3. The failure of the FAA to require Airworthiness Directive 87-21-08 inspection of all the lap joints proposed by Boeing Alert Service Bulletin SB 737-53A1039; and
4. The lack of a complete terminating action (neither generated by Boeing nor required by the FAA) after the discovery of early production difficulties in the B-737 cold bond lap joint which resulted in low bond durability, corrosion, and premature fatigue cracking.

The FAA report is published on faa.gov/about/initiatives

Air Ontario Flight 1363

Main wikipage: Air Ontario Flight 1363

Air Ontario Flight 1363, a Fokker F-28 jet, crashed during takeoff from Dryden Municipal Airport, Ontario, Canada on March 10, 1989. Of the 69 persons on board, 24 suffered fatal injuries.

The aircraft had suffered from a malfunctioning auxiliary power unit (APU) for the five days preceding the accident. Throughout the week preceding March 10, Air Ontario maintenance attempted, with limited success, to cure the APU problems. On March 9 it was decided to defer the repair of the APU until the aircraft returned to Toronto on the night of March 10. This meant that the aircraft was dispatched with the APU inoperable.

On the morning of March 10, the jet departed Winnipeg on a round trip flight to Dryden, Thunder Bay and back. Since no external power unit was available at Dryden, the engines couldn't be restarted in case of engine shutdown on the ground.

The flight to Thunder Bay was unentful apart from a slight delay due to poor weather at Thunder Bay. As the aircraft was prepared for the return flight, it appeared that the aircraft was overweight as a result of ten additional passengers having transferred to the flight due to an earlier cancellation. The Air Ontario duty manager decided to off-load fuel and to arrange refuelling at Dryden. This caused an additional delay of 35 minutes.

The Fokker F-28 departed Thunder Bay at 11:55 hours EST, about one hour behind schedule. The aircraft landed at Dryden at 11:39 hours CST. It began to snow lightly when the aircraft landed.

Between 11:40 and 12:01, Air Ontario 1363 was refuelled with the right engine operating and with the passengers remaining on board the aircraft. This so called 'hot refuelling' procedure was followed because the APU was unserviceable. Eight passengers deplaned in Dryden and seven passengers boarded the aircraft.

Meanwhile, snow was accumulating on the wings, forming a layer of 1/8-1/4 inch. No de-icing was done because de-icing with either engine running was prohibited by both Fokker and Air Ontario.

The aircraft then taxied to runway 29 for departure, but was instructed to hold as there was a Cessna 150 on approach. The snow was continuing to fall heavily, becoming increasingly thick on the wings.

At 12:09 the aircraft started it's takeoff roll on the slush-covered runway 29. There was an accumulation of at least one-half inch of wet, layered snow on the wings of the F-28 as it began its takeoff roll.

After a longer than normal takeoff roll, the aircraft was rotated near taxiway Alpha, at approximately the 3500 foot mark. The aircraft lifted off slightly, began to shudder, and then settled back down onto the runway. The takeoff roll then continued and the aircraft was rotated a second time, finally lifting off at approximately the 5700 mark of the 6000 foot runway. It flew over the end of the runway approximately 15 feet above the ground. It thereafter failed to gain altitude and mushed through the air in a nose-high attitude, before commencing to strike trees.

The aircraft crashed and came to rest in a wooded area, 3156 feet past the runway end and caught fire.

After a 20-month investigation, it was concluded that "Captain [-], as the pilot-in-command, must bear responsibility for the decision to land and take off in Dryden on the day in question. However, it is equally clear that the air transportation system failed him by allowing him to be placed in a situation where he did not have all the necessary tools that should have supported him in making the proper decision."

British Airways Flight 5390

Main wikipage: British Airways Flight 5390

On 10 June 1990, British Airways Flight 5390 took off from Birmingham Airport in England and headed towards Málaga Airport in Spain. Shortly after takeoff, its windscreen panel separated from its frame, causing the explosive decompression of the cockpit. The plane's captain was sucked out of the cockpit and was blown partially out of the aircraft. The flight attendant succeeded to keep the captain's legs in the cockpit.

This flight attendant believed that the captain is dead, but the crew was afraid that the captain's body can destroy the engine if released.

With the captain pinned against the window frame for twenty minutes, the first officer managed to land at Southampton Airport. Although the captain was seriously injured, he survived. No loss of life occurred.

The investigation determined that the windscreen panel was not properly installed on the airplane one day before the accident.

Alaska Airlines Flight 261

Main wikipage: Alaska Airlines Flight 261

Alaska Airlines Flight 261, a McDonnell Douglas MD-83 aircraft, experienced a fatal accident on January 31, 2000, in the Pacific Ocean. The two pilots, three cabin crewmembers, and 83 passengers on board were killed and the aircraft was destroyed.

The subsequent investigation by the National Transportation Safety Board (NTSB) determined that inadequate maintenance led to excessive wear and catastrophic failure of a critical flight control system during flight. The probable cause was stated to be “a loss of airplane pitch control resulting from the in-flight failure of the horizontal stabilizer trim system jackscrew assembly’s acme nut threads. The thread failure was caused by excessive wear resulting from Alaska Airlines insufficient lubrication of the jackscrew assembly.

The stuck horizontal tail hinders operation of the balancing system. Investigators found that the maintenance took only about an hour to complete. In fact, the plane's manufacturer expected the maintenance work to take about four hours to complete, suggesting the mechanic wasn't up to the job.

China Airlines Flight 611

Main wikipage: China Airlines Flight 611

On May 25, 2002, China Airlines Flight 611, Boeing 747-200, took off Taiwan's Zhongzheng International Airport while heading to Hong Kong International Airport, but broke into pieces in mid-air and crashed in the waters near Penghu, killing all 206 passengers and 19 crew members on board. The accident was the result of metal fatigue caused by inadequate maintenance after a previous incident.

During the permanent maintenance of China Airlines, the maintenance personnel discovered the severe metal fatigue skin and, instead of replacing the whole skin according to the structural maintenance manual prescribed by Boeing, just covered the area with an aluminum plate similar in size to the damaged skin. However, the maintenance personnel indicated on the maintenance record that the maintenance was carried out in accordance with the Boeing maintenance guidelines. Follow-up maintenance personnel believed his maintenance record and were not checked.

In fact, after investigation, it was found that the aircraft had maintenance records before the accident and the tail skin was damaged, but the maintenance personnel did not replace the whole skin according to the requirements of the maintenance manual. But only the damaged part was repaired. After the aircraft climbed, the accumulated metal fatigue here led to the falling off of the whole tail, which eventually led to the crash of the aircraft. This is very similar to the original Aloha accident in the United States, which is caused by the accumulated metal fatigue caused by long-term rain erosion.

The reason is that on February 7, 1980, the aircraft damaged the machine tail skin at the time of flying, and was transported back to Taiwan for temporary maintenance on the same day. However, it only covers the area with an aluminum plate with an area that is similar to the damaged skin, and does not replace the one-piece skin with the maintenance guidelines prescribed by Boeing, which thus accumulates the metal fatigue. After the crack, the aircraft tail fell off and out of control, and finally crashed through the loss of pressure and control.

Colgan Air Beech 1900D

Main wikipage: Colgan Air Beech 1900D

On August 26, 2003, a Colgan Air Beech 1900D crashed just after takeoff from Hyannis, Massachusetts. Both pilots were killed.

The improper replacement of the forward elevator trim cable and subsequent inadequate functional check of the maintenance performed that resulted in a reversal of the elevator trim system and a loss of control in flight. Factors were the flight crew's failure to follow the checklist procedures and the aircraft manufacturer's erroneous depiction of the elevator trim drum in the maintenance manual.

Chalk's Ocean Airways Flight 101

Main wikipage: Chalk's Ocean Airways Flight 101

On December 19, 2005, a Grumman Turbo Mallard (G-73T) amphibious airplane, N2969, operated by Flying Boat, Inc., doing business as Chalk’s Ocean Airways flight 101, crashed into a shipping channel adjacent to the Port of Miami, Florida, shortly after takeoff from the Miami Seaplane Base. Flight 101 was a regularly scheduled passenger flight to Bimini, Bahamas, with 2 flight crewmembers and 18 passengers on board. The airplane’s right wing separated during flight. All 20 people aboard the airplane were killed, and the airplane was destroyed by impact forces. Flight 101 was operating under the provisions of 14 Code of Federal Regulations Part 121 on a visual flight rules flight plan. Visual meteorological conditions prevailed at the time of the accident.

​The National Transportation Safety Board determines that the probable cause of this accident was the in-flight failure and separation of the right wing during normal flight, which resulted from (1) the failure of the Chalk's Ocean Airways maintenance program to identify and properly repair fatigue cracks in the right wing and (2) the failure of the Federal Aviation Administration (FAA) to detect and correct deficiencies in the company's maintenance program.

The complete report is published on ntsb.gov/investigations

See also

• https://www.faa.gov/data_research/accident_incident/