BOAC flight 712
| BOAC flight 712 | |
|---|---|
 Sister aircraft of the Boeing 707-436 type |
|
| Accident summary | |
| Accident type | Emergency landing after engine fire |
| place | London Heathrow Airport |
| date | April 8, 1968 |
| Fatalities | 5 |
| Survivors | 122 |
| Injured | 38 |
| Aircraft | |
| Aircraft type | Boeing 707-465 |
| operator | British Overseas Airways Corporation |
| Mark | G-ARWE |
| Surname | Whiskey echo |
| Departure airport | London Heathrow Airport |
| Destination airport | Kingsford Smith International Airport , Sydney , Australia |
| Passengers | 116 |
| crew | 11 |
| Lists of aviation accidents | |
BOAC flight 712 was an overseas flight operated by the British Overseas Airways Corporation ( BOAC ) and was scheduled to fly from London to Sydney on April 8, 1968 . Stopovers were planned in Zurich and Singapore . After take-off, one of the aircraft's engines caught fire and came off the machine. The pilots managed to return to London Heathrow Airport with the burning machine and to complete a successful emergency landing . In the fire that spread during the evacuation, four passengers and one crew member died and 38 other passengers were injured.
plane
The plane that crashed was a six-year-old four-engine Boeing 707-465 that had been ordered by Cunard Eagle Airways in 1961 . The aircraft was equipped with four Rolls-Royce Conway 508 turbofan engines. The machine was delivered to the airline BOAC-Cunard on July 7, 1962 and taken over by BOAC after its dissolution in 1966. Until the accident she had completed 20,870 flight hours.
A similar incident occurred with this aircraft at Honolulu Airport on November 21, 1967 , when a turbine wheel of engine no.4 broke during take-off and parts were thrown away damaging a fuel tank and a fire broke out, which will be extinguished after the take-off is aborted could. The machine was repaired and all four engines were replaced.
crew
The captain of the flight was the 47-year-old Charles WR Taylor, who had over 14,800 hours of flight experience, more than 1,500 of them on the Boeing 707. Captain Taylor was supported by two officers, the senior first officer (in the right seat of the copilot) Francis Kirkland, 32 years old, and 30 year old John Hutchinson ( Acting First Officer , on the jump seat ). Kirkland had completed over 5,400 flight hours, including over 2,800 on the Boeing 707. Hutchinson had more than 4,100 flight hours, of which 680 on the 707. The flight engineer was Thomas C. Hicks, 35 years old, with over 6,400 flight hours, 191 of them on the 707. The 50-year-old flight captain Geoffrey Moss was a check-captain for one Checking on board by Captain Taylor.
The aircraft crew included six flight attendants.
Take-off procedure and emergency landing
Flight 712 took off from runway 28 links (now referred to as 27L) at 3:27 p.m. UTC . 20 seconds later the cockpit crew heard a bang and felt the aircraft jolt. The instruments showed that engine number 2, the one on the inboard position of the left wing, had failed; at the same time, it automatically slammed the thrust lever of this engine towards the idle position. When flight engineer Hicks pulled the lever all the way to idle, the warning signal sounded that warns of a too low throttle position if the landing gear is not extended (this was meanwhile retracted). While Captain Taylor and the flight engineer acknowledged and switched off this sounding warning signal at the same time, co-pilot Hutchinson mistakenly switched off the fire alarm that was sounding at the same time, so that the flight engineer apparently no longer felt compelled to operate the lever for the emergency fuel valve for engine 2. This would have disconnected the entire engine system, including the feed line in the pylon, from the fuel supply and armed the engine's extinguishing system. Likewise, the hydraulic installations in the engine nacelle would have been separated from the rest of the aircraft's circuit.
The check captain Moss, who was also in the cockpit, recognized, when he looked out the window, that engine number 2 was burning. Hutchinson radioed Mayday to the tower, then proceeded to the engine fire-fighting procedure. This led to misunderstandings with the flight engineer about the checklist. Captain Taylor informed the tower that he would be returning to the airport. The air traffic control only offered after a traffic pattern back on the track 28L to land and alerted at the same time, the airport fire brigade. After the Mayday call, the crossing runway 05 on the right (no longer available today or only partially used as a taxiway ) was released due to the worsening of the situation . This significantly shortened the remaining flight time and distance to landing.
90 seconds after the fire broke out, the engine detached itself from the attachment and plunged into a water-filled gravel pit. The cockpit crew noticed nothing of this, and the warning light for the engine fire went out when the engine nacelle fell off. Nevertheless, the crew had become aware of the fire. Due to the failure of the emergency shutdown of the fire valve and the continued running pre-feed pump, a large amount of fuel continued to squirt out of the destroyed and finally torn off fuel line at the engine pylon, which continued to burn there even after the engine fell. The flames hit the top and bottom of the wing.
While the landing gear could be extended during the approach, the landing flaps could no longer be fully extended due to damage to the hydraulics . The machine had reached a height of about 1,000 meters and a speed of over 400 km / h. In addition to the problem with the landing flaps, there was also the fact that runway 05 on the right had no glide slope guidance . Captain Taylor nevertheless managed to land the machine safely and to bring it to a standstill about 1,600 meters behind the runway threshold using the wheel brakes and the thrust reverser of engines 1 and 4. The flight lasted a total of 3 minutes 32 seconds.
By reversing the thrust of the external engines, the flames from the source of the fire on the remaining engine pylon 2 were pushed towards the fuselage. During the shutdown procedure of the engines there was an explosion of a fuel tank in the left wing. A large amount of fuel was released and debris was thrown over the fuselage to the other side of the aircraft.
Evacuation and full fire
The cabin crew had prepared the passengers for the emergency landing. After the aircraft stopped and the explosion on the left wing, the captain ordered the immediate evacuation, the flight attendants opened the emergency exits and activated the emergency slides. The passengers began to exit the Boeing via the emergency exits on the starboard side (right). However, burning fuel released by the explosion had spread under the rear fuselage, greatly increasing the area of the fire. Continued running fuel pumps, which, contrary to the emergency procedures, had not been switched off, and further explosions, even more fuel was released on the left side. As a result, the rear exits and the emergency exits above the wings could no longer be used. The majority of the survivors left the machine using the front escape slides. The cockpit crew escaped from the cockpit side windows using emergency ropes.
The first units of the airport fire brigade reached the burning machine during the evacuation. The firefighters prevented the fuel in the starboard tanks from igniting. Four passengers and a flight attendant did not manage to leave the burning machine. They died of smoke inhalation. 38 of the passengers were injured.
examination
The British investigative authority AAIB ( Air Accidents Investigation Branch ) led the investigation into the accident.
The investigators came to the conclusion that material fatigue on the impeller of the fifth stage of the low-pressure compressor caused it to burst, which damaged the housing of the compressor of engine 2. Debris destroyed the fuel line, the escaping fuel ignited on hot parts. The engine cowling was also blown away; it was found at the end of the runway. Due to the accidental shutdown of the fire alarm and errors when working through the emergency checklists, the fuel emergency shut-off valve was not activated, so fuel continued to be pumped into the seat of the fire. After 90 seconds, the light metal construction of the engine mount was so weakened by the fire that the engine fell off.
After the engine dropped out, it continued to burn at the point where the fuel leaked on the broken suspension. Even firing the extinguishing bottles filled with inert gas in good time would presumably have had no effect due to the missing cladding, but the fire would have been deprived of its nourishment by the routine closing of the emergency fuel shut-off valve. It was also determined that the efficiency of the airport fire brigade was severely impaired by insufficient or incorrect equipment.
Honor
The flight attendant Barbara Jane Harrison, who died in the accident, was posthumously honored by Queen Elizabeth II with the George Cross . Her father Alan accepted the award for his daughter, who was honored for her courage in the evacuation. It was the only award of the George Cross to a woman in peacetime so far. Harrison was also the youngest woman honored.
The flight attendants Neville Davis-Gordon and the passenger John Davis, who survived the accident unharmed, were also honored for their selfless efforts in the evacuation. Davis-Gordon was awarded the British Empire Medal and Davis was awarded the Order of the British Empire .
Web links
Individual evidence
- ↑ Report of the AAIB, Chapter 1.1, Pages 3 to 4 (Eng.)
- ↑ Report of the AAIB, Chapter 1.1, Page 5 (Eng.)
- ^ Announcement in the Supplement to The Gazette of August 8, 1969, page 8211 (engl.)
- ↑ Article The Last Flight of Whiskey Echo in Airplane magazine , No. 6 (422), pages 30-35.
- ^ Announcement in the Supplement to The Gazette of August 8, 1969, page 8213 (engl.)