Narrative:The aircraft was engaged on a series of charter flights, carrying oil company personnel between Aberdeen, Scotland and Sumburgh, Shetland Islands. The inbound flight to Sumburgh had been made without incident and no significant malfunction of the aircraft had been reported.
The crew, consisting of two pilots and a stewardess, then had a stopover of nearly seven hours before departing on the return flight, Dan-Air 0034, with 44 passengers on board. It has not been established who was the handling pilot on this sector.
At 15:48 hrs, in conditions of moderate visibility, but with low cloud, rain and a fresh easterly wind, the aircraft was taxied out to the holding point 'India', the intersection of the disused runway and runway 15/33. Meanwhile the stewardess gave the company's standard safety briefmg, using a megaphone because the passenger address (PA) system was 'screeching'. The briefing included mention of the location of the lifejackets, how they should be put on, and the method of inflation; also mentioned was the location of the emergency exits. A diagram displaying the method of donning the jackets was fixed to the forward bulkhead of the cabin.
Because of other aircraft movements, 'KF' was held at point 'India' for six minutes before being cleared, at 15:57 hrs, to 'enter and backtrack' for a take-off on runway 09, which was virtually into wind. Whilst the aircraft was backtracking, ATC passed the crew the en route clearance, which was read back correctly by the co-pilot. The aircraft was seen to turn close to the western end of the runway and line up on the runway heading.
At 15:59 hrs the flight received take-off clearance from ATC and this was acknowledged by the co-pilot. There is evidence to show that the engines were accelerated whilst the aircraft was held stationary on the brakes and that full take-off power, using watermethanol, was achieved on the take-off run, which commenced at almost exactly 16:00 hrs.
Evidence from the aircraft's Flight Data Recorder (FDR) shows that the aircraft accelerated normally through the decision speed, V1 (92 kts), to the rotation and safety speed VR/2 (99 kts). No rotation was carried out and even though the aircraft reached a speed significantly higher than VR of the order of 113 kts, it failed to become airborne.
About 5 seconds after reaching the scheduled rotation speed, and after passing the intersection with the disused runway, the aircraft began to decelerate. Veering gradually to the left as it crossed the grass overrun area, it then made contact with a discontinuity or 'step', approximately 40 centimetres high, at the edge of the airfield perimeter road and partial collapse of the undercarriage followed. After crossing the road in a left wing low and nose down attitude the aircraft passed over the inclined sea defences and came to rest in the sea some 50 metres from the shore line.
The emergency services arrived at the point on the road adjacent to the crash site within two minutes of the accident. However, about a minute later the aircraft sank, nose first, in some ten metres of water, leaving only the rear section of the fuselage visible. Twenty-nine passengers and the stewardess were rescued, or managed to swim to the shore, under adverse weather conditions. Despite rescue attempts mounted from the shore, by small craft and by helicopters summoned to the scene, fifteen passengers and the two pilots died by drowning.
Probable Cause:
PROBABLE CAUSE: "It was concluded that the accident was caused by the locked condition of the elevators which prevented the rotation of the aircraft into a flying attitude. It is likely that the elevator gust-lock became re-engaged during the pilot's pre-take-off check, and that this condition was not apparent to either pilot until the take-off was so far advanced that a successful abandonment within the overrun area could not be reasonably have been made. The re-engagement of the gust-lock was made possible by the condition of the gust-lock lever gate plate and gate-stop strip."
Accident investigation:
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Investigating agency: | AIB (U.K.) |
Status: | Investigation completed |
Duration: | 1 year and 10 months | Accident number: | AAR 1/1981 | Download report: | Final report
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Classification:
Locked rudders/ailerons/gustlock
Runway excursion
Sources:
» Flight International 25 July 1981 (216-217)
Follow-up / safety actions
All British HS-748 planes were fitted with a light on the gust-lock lever to warn the pilots if the lever is not properly in the controls-free detent. Also, Dan-Air redesigned the lifejacket stowage.
AIB issued 10 Safety Recommendations
Issued: 12-MAY-1981 | To: | G-BEKF(1) |
Serious consideration be given to the re-design of the gust-lock system so as to ensure that positive operation of the gust-locks is achieved at all times and\'that the possibility of the crew being misled as to the position of any lock is eliminated. |
Issued: 12-MAY-1981 | To: | G-BEKF(10) |
Where not already provided, loud hailers be included in the scale of emergency equipment at all aerodromes of Category VI and above |
Issued: 12-MAY-1981 | To: | G-BEKF(2) |
CVR\'s be fitted to all public transport category aircraft which exceed 11,400 kg maximum authorised weight. |
Issued: 12-MAY-1981 | To: | G-BEKF(3) |
In the case of airports with runways facing out to sea, the airport authorities concerned and the Home Office (through the Police) liaise with the Department of Trade, Marine Division (through HM Coastguard) so that procedures for rescue close offshore may be agreed and promulgated. |
Issued: 12-MAY-1981 | To: | G-BEKF(4) |
Aerodromes operated by the CAA be licensed in accordance with the requirements for other aerodromes. |
Issued: 12-MAY-1981 | To: | G-BEKF(5) |
The content of CAP 168, Licensing of Aerodromes, be reviewed in the interests of upgrading the safety margins contained therein. |
Issued: 12-MAY-1981 | To: | G-BEKF(6) |
The CAA reconsider the possibility of the provision of some form of retardation device in or beyond overrun areas at critical aerodromes. |
Issued: 12-MAY-1981 | To: | G-BEKF(7) |
Demonstrations of the method of donning and of the operation of life-jackets be required, and individual safety leaflets be provided, on all public transport flights which take-off or land directly over water. |
Issued: 12-MAY-1981 | To: | G-BEKF(8) |
Consideration be given to re-positioning life-jacket stowages in HS 748 and other aircraft with similar stowage arrangements, so as to improve their accessibility. |
Issued: 12-MAY-1981 | To: | G-BEKF(9) |
A suitable launching device for lifelines be developed and provided at coastal aerodromes. |
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Photos
accident date:
31-07-1979type: Hawker Siddeley HS-748-105 Srs. 1
registration: G-BEKF
Map
This map shows the airport of departure and the intended destination of the flight. The line between the airports does
not display the exact flight path.
Distance from Sumburgh Airport, Shetland Islands to Aberdeen-Dyce Airport as the crow flies is 300 km (187 miles).
Accident location: Exact; deduced from official accident report.
This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.