British Airways Flight 5390

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British Airways Flight 5390
BAC 111 510.jpg

A British Airways BAC 111-500
Accident summary
Accident type Structural failure
place Didcot , Oxfordshire , UK
date June 10, 1990
Fatalities 0
Survivors 87 (all)
Injured 2
Aircraft
Aircraft type BAC 111-500
operator British Airways
Mark G-BJRT
Surname "County of South Glamorgan"
Passengers 81
crew 6th
Lists of aviation accidents

On June 10, 1990, an incident occurred on British Airways flight 5390 from Birmingham to Málaga . The deployed BAC 111-500 lost a cockpit window during the flight at 07:33 UTC . This resulted in a pressure drop that tore the master half out of the cabin. The co-pilot and cabin crew were able to prevent people from suffering serious damage.

the accident

British Airways BAC-1-11 ( registration number : G-BJRT, baptismal name: "County of South Glamorgan") took off at 07:20 UTC with a 60-minute delay from Birmingham Airport with the destination Malaga. When the aircraft had climbed to a height of 17,300  ft (approx. 5,300  m ) at a speed of 300  kn (556  km / h ), the left cockpit window was torn out of the anchorage. Captain Tim Lancaster , who had just unbuckled himself, was half pushed out of the window by the pressure. His feet got caught in the control column, which prevented him from being blown completely out of the aircraft. The movement of the steering column caused the aircraft to tilt 6 ° downwards and turn 25 ° to the right. The outside temperature at this altitude was −17 ° C.

Flight attendant Nigel Ogden, who had just left the cockpit, heard a bang and noticed the clouds of mist that filled the cabin, indicating a sudden loss of pressure. He returned immediately, grabbing Lancaster by the waist, securing the captain.

The cockpit door was torn and partially over the controls. Numerous objects were torn loose by the draft and blown out of the window, including an oxygen cylinder and its anchoring.

Copilot Alastair Atchison was still buckled up and initially had problems steering the aircraft, as Lancaster's legs and remains of the cockpit door blocked the left control column. Atchison then initiated a descent to get to an altitude with enough oxygen. He deliberately did not put on his oxygen mask in order to be able to continue talking to the crew.

In the meantime, the cabin chief John Heward had also come into the cockpit, secured himself with the strap of the jump seat , in turn held Ogden and was able to secure him with the harness of the captain. Even with the help of the third flight attendant, Simon Rogers, they were unable to pull Lancaster back into the cockpit against the wind pressure.

Atchison had meanwhile made an emergency call and stated that it would sink to 10,000 ft (approx. 3,000 m) due to a loss of pressure. He also reduced the speed to 150 kn (278 km / h). The noise in the cockpit made it difficult for Atchison to understand the answer from the air traffic controller in London. The air traffic controller accepted the emergency call, but waited for further information from the co-pilot and meanwhile continued to work normally. However, this did not lead to any problems, except that the responsible authorities were informed late.

Atchison was radioed to the nearest airport in Southampton . He managed to land the plane safely at 7:55 a.m. During the entire time, about two-thirds of Lancaster was hanging out of the cockpit window. While still on the runway, the passengers got off the stairs while rescue teams rescued the captain.

Contrary to initial fears, Lancaster had survived and regained consciousness after landing. He suffered broken bones, bruises and frostbite, but was able to return to work after five months. The steward Nigel Ogden suffered a dislocated shoulder and facial frostbite while securing the captain. In 2001, Ogden finally had to quit his job due to a post-traumatic stress disorder .

The lost window was later found near Cholsey , Oxfordshire .

Cause of accident

The fact that the cockpit glazing fell out can be explained by a chain of inattentions and mistakes in maintenance. The flight was the first of this aircraft after maintenance in the hangar, during which the left cockpit window was also replaced due to a defect report. This work was carried out in the early hours of the day before. Since the shift was scarce, the shift supervisor took on this work himself.

Contrary to the regulations, the left cockpit window had not previously been fastened with 90 countersunk screws of the type A211-8D, but with the variant A211-7D, which was 2.5 mm shorter. Since the last window replacement was four years ago, this had obviously not led to any problems.

The shift supervisor removed the window with the help of a colleague. Since some screws were damaged in the process and others showed signs of rust, he decided to get new screws from the spare parts store. Screws of this size do not have a designation and the shift supervisor did not bother to determine the correct prescribed part number, but contented himself with one of the old screws as a sample.

The employee in the spare parts warehouse pointed out to the shift supervisor that the correct size was not 7D, but 8D, but the shift supervisor did not respond because he had just removed screws of the 7D type.

Since there were not enough screws of size 7D in stock in this spare parts warehouse, the shift supervisor went to another warehouse at the airport that was not manned at the time. There he took out more screws that he thought were 7D, but were actually 8C. These were the same length as the mandatory 8D, but the diameter was about 0.7 mm less. He also took six size 9D screws with him because he felt the corner screws should be longer.

The service instructions specified a torque of 15 lbf in (about 24 Nm ) for the screws  , but the shift supervisor decided to tighten the screws to 20 lbf in. A calibrated torque wrench was not available so he used a torque screwdriver.

Due to the awkward position of his mobile work platform and the fact that he had to use both hands, he had no direct view of the screws. He used 84 of the new screws. When he got to the six corner screws, he realized that he was wrong and that the 9D screws he had intended did not fit. Here he used the old screws. The shift supervisor did not notice that the countersunk heads of the new screws were deeper than the old ones.

The work was only checked by testing the function of the window heating. Since the work was done by the shift supervisor himself, there was no one to check his work that night. A second person check was also not required because replacing a cockpit window was not viewed as a critical action.

The following night, before the aircraft took off, the shift supervisor also replaced a cockpit window on another machine. He noticed that this was not fastened with 7D but with 8D screws, but considered the difference to be a modification of the series over the years and did not attach any importance to it.

In most commercial aircraft, the cockpit windows are installed from the inside out so that the higher internal cockpit pressure presses them into their sockets. With the BAC 1-11, however, the panes are installed from the outside in and screwed on from the outside. The necessary holding force is applied exclusively through the screw connection. Therefore, if the screws fail, the glazing can be pushed outward and torn off.

British Airways' immediate action

When it first became known that screws of insufficient length were being used, British Airways arranged an extraordinary investigation of all BAC 1-11 before the next take-off. Every fourth screw on the cockpit window should be removed and measured. Wrong screws were found on several aircraft.

When, in the further course of the investigation, it became known that some screws with too small a diameter were used in the incident, this led to a second investigation of all aircraft. A visual inspection, which was carried out on all screws, was sufficient here. However, screws that were too thin were not found in any of the aircraft examined.

The accident in the media

The accident of British Airways flight 5390 was shown in the Canadian television series Mayday - Alarm im Cockpit with the English title Blow Out and the German title Horrorflug 111 . In simulated scenes, animations and interviews with those involved and investigators, reports were made about the preparations, the process and the background of the flight.

Web links

Individual evidence

  1. ↑ This is your captain screaming. The Sydney Morning Herald, February 5, 2005, accessed November 19, 2016 .
  2. ↑ Fernsehserien.de: episode guide. Retrieved January 6, 2011 .

Coordinates: 51 ° 36 ′ 21 ″  N , 1 ° 14 ′ 27 ″  W.