Douglas Barrie/LONDON

THE BRITISH Aerospace Hawk, which crashed at the Royal Air Force training base at Valley, North Wales, in February took off with its ailerons disconnected after maintenance. This was one of a series of human errors contributing to the crash, according to initial investigations.

The 13 February crash was the sixth suffered by UK combat aircraft since the beginning of the year. A further three aircraft have since been lost, giving rise to concerns that resources are being over-stretched in the wake of defence cuts. Two of the aircraft were Royal Navy British Aerospace Sea Harriers, and the remainder were from the RAF. The UK lost ten service aircraft in total in 1995.

The initial RAF accident bulletin indicates that the Hawk's ailerons were disconnected. The RAF declines to comment.

The aircraft had been taken off the flight line for non-destructive testing, at which point the ailerons were disconnected. Part of the investigation is focusing on concerns over the documentation covering the work of the aircraft. The Hawk has hydro-mechanical controls, with the exception of the rudder, which is mechanical.

The ailerons should have been reconnected before the aircraft was returned to the flight line. As part of the pre-flight checks, correct control-surface input and movement should also have been, visually confirmed by the pilot and ground crew. The pilot would have been unable to tell from stick feel that the ailerons were disconnected. The bulletin re-stressed that aircrew must make sure, that all control surfaces move correctly, as part of the pre-flight checks.

The aircraft began to roll shortly after take-off. The pilot is believed to have ejected at low level as the aircraft rolled beyond 90° and was killed.

There is growing service concern that, while the incidents are technically unrelated, they may indicate the extent to which RAF resources and capabilities are over-stretched.

Source: Flight International