East African Airways Flight 720

from Wikipedia, the free encyclopedia
East African Airways Flight 720
East African Airways Vickers VC-10 Groves-1.jpg

The crashed machine
Accident summary
Accident type Departure from the runway due to a defect in the braking system
place Addis Ababa Airport , EthiopiaEthiopia 1941Ethiopia 
date April 18, 1972
Fatalities 43
Survivors 64
Injured 15th
Aircraft
Aircraft type United KingdomUnited Kingdom Vickers Super VC10
operator KenyaKenyaTanzaniaTanzaniaUgandaUganda East African Airways
Mark UgandaUganda 5X-UVA
Departure airport Nairobi Airport , Kenya
KenyaKenya 
1. Stopover Addis Ababa Airport , EthiopiaEthiopia 1941Ethiopia 
2. Stopover Rome Fiumicino Airport , ItalyItalyItaly 
Destination airport London Heathrow Airport , UKUnited KingdomUnited Kingdom 
Passengers 96
crew 11
Lists of aviation accidents

The East African Airways Flight 720 (Flight number: EC720 , call sign: EASTAF 720 ) was an international line intercontinental flight of East African Airways from Nairobi to London with stops in Addis Ababa and Rome . On April 18, 1972, a serious aircraft accident occurred on this flight when a Vickers Super VC10 at Addis Ababa Airport suffered a tire damage and then rolled over the end of the runway. In the accident, 43 people were killed on board the machine.

machine

The machine concerned was a Vickers Super VC10 with the serial number 881 . It was one of three identical machines that East African Airways ordered from the British Aircraft Corporation in March 1965 . The final assembly took place in 1966, the first flight from Brooklands to Wisley was carried out on September 3, 1966. Since the planned four Conway 43 Mk550B engines were not yet available, a set of Conway Mk540 engines from a conventional Vickers VC10 was installed for the first flight. A review flight was carried out in September 1966. The machine took off from London Airport with a full tank of fuel and was then flown from Le Havre to Stornoway, with climbing maneuvers being flown. On September 30, 1966, the machine was ceremoniously handed over to East African Airways in Wisley. The machine received the Ugandan aircraft registration 5X-UVA . The delivery flight was carried out on October 11, 1966 from London Heathrow Airport, with the machine being flown by flight captain GW Mitchell, who was East African Airways' chief inspection captain for machines of the Vickers Super VC10 type. First officer was Lew Roberts of the British Aircraft Corporation. The flight was delayed by an hour because not all documents for the rental / purchase agreement were available for the planned start of the flight. The machine was flown to Nairobi via Rome and Cairo. On October 13, 1966, scheduled flight operations were started with East African Airways. On September 7, 1967, at 1 p.m. in Nairobi, the plane took off for a demonstration flight to Hong Kong via Addis Ababa , Karachi , Bombay and Bangkok . Captain Reg Cartwright carried out the first landing of a Vickers Super VC10 machine at Kai Tak Airport , and it was also the first landing of an East African Airways machine at this airport. Five hours later, the machine took off for its return flight and flew over Da Nang at an altitude of 36,000 feet in order to stay outside the flight paths of the Boeing B-52 bombers , which were flying missions from Guam during the ongoing Vietnam War . The four - engined long - haul aircraft had completed a total operating performance of 18,586 operating hours by the time of the accident.

Passengers and crew

96 passengers had started the flight segment from Addis Ababa. The eleven-person crew consisted of a four-person cockpit crew and a seven-person cabin crew.

Cockpit crew

  • The 42-year-old captain JP Vale had a flight experience of 8,769 flight hours, 752 of which he had completed in the cockpit of the Vickers VC10.
  • The 26-year-old first officer RPH Botto had completed a total of 2,744 hours of flight experience by January 12, 1972, 640 hours of which with the Vickers Super VC10. For the period after that date, no type-disaggregated records of his aviation activities were available.
  • The 34-year-old flight engineer BAH Twist had completed a total of 3,577 hours of flight experience by October 11, 1971, of which he had spent 1,513 hours in the cockpit of the Vickers Super VC10. For the period after that date, no type-disaggregated records of his aviation activities were available. He also held a commercial pilot's license with type rating for the Piper PA-28 .
  • The 45-year-old navigation officer FD MacNabb had a flight navigator license that was valid for all types of aircraft. His flying experience was 20,653 hours.

Cabin crew

The seven-person cabin crew consisted of the purser Paul Mwicigi, the chief flight attendant Jociphares Malole, the oldest flight attendant Yaeri Kagezi, the flight attendants Bakamazi, Mwangi and R. Ayiro and the flight attendant Miriam Fadhill.

the accident

The plane, which was to be used for a flight to London, took off from Nairobi at 06:55 a.m. local time with 121 passengers and 11 crew members. After a routine first flight segment for a scheduled stopover, the aircraft landed in Addis Ababa at 8:23 a.m. Once there, 40 passengers disembarked and some cargo was unloaded. 15 new passengers boarded the aircraft for the onward flight.

Clearance for taxiing to the runway was given at 09:21, and seven minutes later the aircraft rolled over the eastern taxiway to the starting point of runway 07. While taxiing to the starting position for the onward flight, the pilots reported several dead birds on the runway at 09:32 which were then removed by the airport fire department . The machine then lined up at the starting point.

The take-off clearance was given at 09:38:40 a.m. Shortly afterwards, the pilots began the take-off run. Approximately in the middle of the runway, shortly before reaching the decision speed (V 1 ), the machine with the nose landing gear rolled over a metal part, whereupon the right tire exploded. A loud bang was heard and strong vibrations were transmitted into the cockpit. Almost at the same time as the tire damage, the nose landing gear lifted off the runway. The pilots decided to abort the take-off , reduced the power of the engines and set reverse thrust . The machine continued to roll across the runway, pulling slightly to the right. Shortly afterwards, the rear left main landing gear tire burst. Shortly before the end of the runway, the machine swerved slightly to the left until it reached approximately the center line of the runway. After the machine had crossed a drainage channel that was at the end of the runway at right angles to the center line, it took off for a moment as it left the threshold of the embankment on which the 60-meter long stop runway was. The left wing brushed against the steel lattice construction of the approach lights for runway 25. A tank in the left wing was torn open. The machine came to a stop about 60 meters behind the runway, in about 10.6 meters of sloping terrain, and caught fire because of the leaking fuel.

Victim

An immediate evacuation of the machine was ordered, but 43 people - 8 of the 11 crew members and 35 of the 96 passengers - were killed as a result of the accident. Two crew members and 13 passengers were injured.

root cause

In the course of the investigation, the metal part that was rolled over was identified as a lost part of the engine cover of a Cessna 185 that had taken off from the same runway four hours and 40 minutes earlier. The rear left landing gear tire that burst at an early stage led to reduced braking performance, but not to the extent that the machine would not have come to a standstill before the end of the runway.

The inspection of the maintenance documents showed that the brake system of the machine had been repaired two weeks earlier, on April 4, 1972. The reason was an observed leak in the area of ​​the main landing gear, from which hydraulic fluid escaped. As part of the maintenance work, a hydraulic clutch and the anti-lock braking system (ABS) were renewed. On April 7, 1972, the rear left main landing gear tire burst during a landing. At this point it was assumed that the cause was a defective ABS and this was replaced again.

An inspection of the braking system of the accident VC10 finally revealed that several spare parts had been incorrectly assembled. In the area of ​​the anti-lock braking system of the second rear brake, there was a seal that did not belong there. The rear left transfer line was installed upside down. Parts of the throttle valve of the fourth front landing gear brake had been incorrectly assembled. The first two assembly errors only resulted in a partial loss of braking force if the vehicle was braked until the anti-lock braking system was activated. The braking force was then 70 percent of the usual value. It was no longer possible to determine why the second rear landing gear brake was not decelerating properly due to the considerable fire damage in this area.

swell