48 years ago today Lufthansa Flight 540 was a scheduled commercial flight for Lufthansa, serving the Frankfurt–Nairobi–Johannesburg route.
The flight engineer was found to have failed to open the slat system bleed air valves as required on the pre-flight checklist. This prevented bleed air from flowing to the 747’s pneumatic slat system and, since the leading edge slats are pneumatically driven, kept it from deploying the leading edge slats for takeoff. The takeoff warning system, which would have sounded an alarm if the flaps had not been set for takeoff, did not have a separate warning that the slats’ pneumatic valve had not been opened by the flight engineer
On 20 November 1974, the Boeing 747-130 that was operating as Flight 540 was carrying 157 people (140 passengers and 17 crew members). It crashed and caught fire shortly after taking off from Jomo Kenyatta International Airport in Nairobi for the last leg of the flight, resulting in the deaths of 55 passengers and 4 crew members. This was the first fatal accident involving a Boeing 747
As the aircraft was making its takeoff from runway 24 at the Jomo Kenyatta International Airport in Nairobi, the pilots felt a buffeting vibration. The captain continued the climb and retracted the landing gear. However, as this was being done, the aircraft started to descend and the stall warning system light came on. The aircraft continued to descend and approximately 3,700 feet (1,100 m) from the end of the runway, the 747 airplane crashed in the grass. It then struck an elevated access road and broke up. The left wing exploded and fire spread to the fuselage. 55 of the 140 passengers and 4 of the 17 crew members died
Aircraft type Boeing 747-130
Aircraft name Hessen
Operator Lufthansa
Call sign LUFTHANSA 540
Registration D-ABYB
Flight origin Frankfurt Airport
Frankfurt, West Germany
Stopover Jomo Kenyatta Int’l Airport
Nairobi, Kenya
Destination Jan Smuts Int’l Airport
Johannesburg, South Africa
Occupants 157
Passengers 140
Crew 17
Fatalities 59
Injuries 55
Survivors 98
The accident was caused by the crew initiating a takeoff with the leading edge flaps retracted, because the pneumatic system which operates them had not been switched on. This resulted in the
aircraft becoming airborne in a partially stalled condition which the pilots were unable to identify in the short time available to them for recovery.
Major contributory factors were:
- Lack of warning of a critical condition of leading edge flap position.
- The failure of the crew to satisfactorily complete their checklist items.
Source – Airline Secret Exposed Facebook Page