42 Years ago today: On 14 May 1977 an IAS Cargo Boeing 707-321C crashed on approach to Lusaka following a fatigue failure of the stabilizer, killing all 6 crew.

Date:Saturday 14 May 1977
Time:09:33 UTC
Type: Boeing 707-321C
Operating for:IAS Cargo
Leased from:Dan-Air Services
Registration:G-BEBP
C/n / msn:18579/332
First flight:1963
Total airframe hrs:47621
Cycles:16723
Engines:Pratt & Whitney JT3D-3B
Crew:Fatalities: 5 / Occupants: 5
Passengers:Fatalities: 1 / Occupants: 1
Total:Fatalities: 6 / Occupants: 6
Aircraft damage:Destroyed
Aircraft fate:Written off (damaged beyond repair)
Location:3,7 km (2.3 mls) W of Lusaka Airport (LUN) (   Zambia)
Phase:Approach (APR)
Nature:Cargo
Departure airport:Nairobi International Airport (NBO/HKNA), Kenya
Destination airport:Lusaka Airport (LUN/FLLS), Zambia

Narrative:
The aircraft departed Nairobi (NBO) at 07:17 for the final leg of a London-Heathrow – Athens – Nairobi – Lusaka cargo flight. Boeing 707 G-BEBP proceeded to Lusaka at FL310. At 09:07 the flight was cleared to descend to FL110. This altitude was reached at 09:23, 37nm DME from Lusaka. A clearance was then given to descend further down to FL70 in 1000 feet steps. At 09:28 the co-pilot reported that the airfield was in sight. Lusaka then cleared the aircraft to descend to 6000 feet (2221 feet above runway elevation) and moments later a clearance was given to make a visual approach for runway 10. At 09:32 flaps were selected to 50 degrees. Suddenly, at 09:33, the complete right-hand horizontal stabilizer and elevator assembly were seen to separate in flight. The aircraft pitched rapidly nose down and dived vertically into the ground from a height of about 800 feet. The main wreckage was located 3660 m from the runway threshold

Probable Cause:

CAUSE: “The accident was caused by a loss of pitch control following the in-flight separation of the right hand horizontal stabilizer and elevator as a result of a combination of metal fatigue and inadequate fail safe design in the rear spar structure. Shortcomings in design assessment, certification and inspection procedures were contributory factors.