Lufthansa Flight 540 was a scheduled commercial flight for Lufthansa, serving the Frankfurt–Nairobi–Johannesburg route.

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages) This article needs additional citations for verification. (May 2018) This article includes a list of general references, but it lacks sufficient corresponding inline citations. (May 2018) This article may be expanded with text translated from the corresponding article in Russian. (September 2018) Click [show] for important translation instructions. Machine translation like DeepL or Google Translate is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 2,630 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Russian Wikipedia article at [[:ru:Катастрофа Boeing 747 в Найроби]]; see its history for attribution. You should also add the template {{Translated|ru|Катастрофа Boeing 747 в Найроби}} to the talk page. For more guidance, see Wikipedia:Translation.

Lufthansa Flight 540

D-ABYB, the 747 involved, seen in July of 1970
Accident
Date	20 November 1974 (1974-11-20)
Summary	Crashed shortly after takeoff due to pilot error and design flaw
Site	Jomo Kenyatta Int'l Airport Nairobi, Kenya 1.3192°S 36.9275°E / -1.3192; 36.9275
Aircraft
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

On 20 November 1974, the Boeing 747-130 that was operating as Flight 540 was carrying 157 people (140 passengers and 17 crew members) 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.[1]

Aircraft and crew

Aircraft

The aircraft involved was a Boeing 747-130 registered as D-ABYB and was named Hessen. It was the second 747 to be delivered to Lufthansa. It made its first flight on 30 March 1970 and was delivered to Lufthansa on 13 April the same year. The aircraft was powered by four Pratt and Whitney JT9D-7 turbofan engines. The aircraft had 16,781 flying hours at the time of the accident.[2]

Crew

The flight crew consisted of 53-year-old captain Christian Krack (who had more than 10,000 flight hours, with 1,619 hours on the Boeing 747), 35-year-old first officer Hans-Joachim Schacke (3,418 flight hours, with more than 2,000 hours on the Boeing 747) and 51-year-old flight engineer Rudolf (Rudi) Hahn (13,000 hours of flying experience).[3][4]

Accident

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.[1]

Cause

The cause of the crash was determined to be a stall caused by the leading edge slats (strictly speaking, outboard variable camber leading-edge slats and inboard Krueger flaps) having been left in the retracted position. Even though the trailing edge flaps were deployed, without the slats being extended the aircraft's stall speed was higher and the maximum angle of attack was lower. As a result, the aircraft was unable to climb out of ground effect. 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 on the 747 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.[5]

The faulty state of the slats should by design have been indicated by yellow warning lights: one for the pilot, and eight for the flight engineer. However, both crew members stated in court that these lights had been green. Three possible explanations have since been offered for this inconsistency: that the morning sun was blinding the cockpit crew and thus hampered color perception, that a construction error could have caused green lights despite the retracted slats, and that the crew lied. None of these possibilities could be conclusively proven.[6][7] The flight crew was blamed for not performing a satisfactory pre-takeoff checklist, but the accident report also faulted the lack of adequate warning systems that could have alerted the crew to the problem.[8][9] Two previous occurrences of this error had been reported, but in those cases the pilots had been able to recover the aircraft in time. After this third, deadly incident, Boeing added systems to warn pilots if the slat valve had not been opened prior to takeoff.

Captain Krack and flight engineer Hahn were dismissed from Lufthansa shortly after, but their dismissals were overturned by a labor court, as there was no investigation report available to rule out the chances of a technical defect.[8]

Flight engineer Hahn was charged with criminal negligence, but was acquitted in 1981. This marks the first crashed Boeing 747.[10]

See also

• List of aircraft accidents and incidents resulting in at least 50 fatalities

Bibliography

• Moorhouse, Earl (1982). Wake Up, It's a Crash! The story of the first ever 747-Jet disaster. A survivor's account. London: Corgi. ISBN 0-552-11932-6.

The final report is this work:

• "Report on Accident to Boeing 747 Registered D-ABYB which occurred on 20th November 1974 at Nairobi Airport, Kenya." East African Community Accident Investigation Branch (Nairobi), 1976. Worldcat entry.

References

External links

External images
Pre-crash photos of the airliner at airliners.net
Pre-crash photos of the airliner at JetPhotos.com

• Accident description at the Aviation Safety Network
• Photos of the crashed airliner from AirDisaster.com^[Usurped!] (Archive^[Usurped!])
• Cockpit Voice Recorder transcript and accident summary

На других языках

[de] Lufthansa-Flug 540

[fr] Vol Lufthansa 540

[it] Volo Lufthansa 540

[ru] Катастрофа Boeing 747 в Найроби