Dan-Air Flight 0034

Dan-Air Flight 0034

Accident summary
Date	31 July 1979
Type	Pilot error (Accidental engagement of gust lock)
Site	Sumburgh Airport, Shetland Islands, Scotland
Passengers	44
Crew	3
Injuries	0
Fatalities	17
Survivors	30
Aircraft type	Hawker Siddeley HS 748
Operator	Dan-Air
Tail number	G-BEKF
Flight origin	Sumburgh Airport
Destination	Aberdeen Airport

Dan-Air Flight 0034 was an oil industry support charter operated by a Hawker Siddeley HS 748 turboprop aircraft from Sumburgh Airport, Shetland Islands to Aberdeen Airport. The aircraft failed to take off and crashed into the sea 50 m (160 ft) offshore on 31 July 1979. Of the 44 passengers and 3 crew members 17 people – including both pilots – died of drowning.

Accident

The aircraft, G-BEKF, was engaged on charter flights between Aberdeen and Sumburgh, carrying oil company personnel. The inbound flight to Sumburgh was made without incident and the crew had a 7 hour stopover before making the return flight to Aberdeen, Dan-Air 0034, with 44 passengers on board.

The aircraft was cleared for takeoff at 15:59 hours and the engines were accelerated while the aircraft was held back by its brakes. The takeoff run commenced at exactly 16:00 hours. Evidence later retrieved from the aircraft's Flight Data Recorder showed that it accelerated normally through the V₁ decision speed of 92 kn (170 km/h; 106 mph), to its V₂ takeoff safety speed of 99 kn (183 km/h; 114 mph). However, no rotation was carried out even though the aircraft significantly exceeded its V_R vertical rotation speed of 113 kn (209 km/h; 130 mph).

About 5 seconds after reaching the scheduled rotation speed the aircraft began to decelerate. It crossed the aircraft perimeter road, passed over the inclined sea defences, and came to rest in the sea 50 m (160 ft) from the shoreline. The aircraft sank in about one minute in about 10 m (33 ft) of water. 29 passengers and the flight attendant were rescued or managed to swim ashore despite the adverse weather conditions. Despite rescue attempts mounted by boat and helicopter, 15 passengers and the 2 pilots died by drowning.

Investigation

The accident was notified by Sumburgh Air Traffic Control at 17:30 hours on 31 July 1979 and the Air Accidents Investigation Branch commenced an investigation the following morning.

The entire wreckage was salvaged and removed for more detailed examination; additional damage resulted from the action of the sea and the salvage operation. Both engines were stripped down and examined but no evidence of pre-impact failure was found. The propeller control units were tested and were discovered to perform within specification. No evidence of fire, smoke, or overheating was found.

It was not established whether the pilot or co-pilot handled the takeoff; though company regulations said that the commander should have performed this due to the co-pilot's inexperience, the compass selector was discovered to have been switched to the co-pilot's instrument. It was however considered possible that it had been moved during evacuation or salvage.

Cause

It was concluded that the accident was caused by the locked condition of the aircraft's elevators which prevented the aircraft rotating into a flying attitude. It was thought likely that the elevator gust lock became re-engaged during the pilots' pre-takeoff checks, and that it was not noticed until the takeoff was so far advanced that a successful abandonment within the overrun area could not be 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, to which non-standard repairs had been made.

The aircraft had originally been bought new by Aerolíneas Argentinas in 1962, and had later been operated by Yacimientos Petrolíferos Fiscales prior to being purchased by Dan-Air in 1977.^[1]

Safety recommendations

The Accident Investigation Branch made nine recommendations:

• That the gust-lock system be redesigned to ensure positive operation at all times and avoid misleading the crew as to the position of any lock.
• That Cockpit Voice Recorders be fitted to all public transport aircraft over 11,400 kg (25,000 lb) maximum weight.
• That the authorities of airports with runways facing out to sea liaise with the Department of Trade through HM Coastguard to agree procedures for close offshore rescue.
• That aerodromes operated by the Civil Aviation Authority be licensed as per the requirements for other aerodromes.
• That the CAA Publication 168 "Licensing of Aerodromes"^[2] be reviewed in the interests of upgrading its listed safety margins.
• That the CAA reconsider the possibility of supplying some kind of retardation device in or beyond the overrun areas at critical aerodromes.
• Demonstrations of how to don and operate lifejackets be required, and individual safety leaflets be provided on all public transport flights which takeoff or land over water.
• Lifejacket stowage in HS 748 and aircraft with similar arrangements be repositioned to improve accessibility.
• A suitable launching device for lifelines be devised and supplied to coastal aerodromes.
• Where not already provided, loudhailers be included in the emergency equipment at all aerodromes of Category VI and above.

Notes

1. ^ Drama in The Air by John Beattie – Robson Books Ltd – 1989 – ISBN 0-86051-664-4, p215
2. ^ "CAP 168: Licensing of Aerodromes". Civil Aviation Authority. February 2007. http://www.caa.co.uk/docs/33/CAP168.PDF. 

References

• "Report name: 1/1981 BAe HS 748, G-BEKF". Air Accidents Investigation Branch. http://www.aaib.dft.gov.uk/cms_resources/1-1981%20G-BEKF.pdf.