Report reveals cause of dramatic crash landing at Marchwood Military Port

The crew of a civilian Sikorsky S-61N Sea King were about to test its hovering capability when it nose-dived and hit the ground, leaving the co-pilot dazed.

No-one was injured in the accident at Marchwood Military Port but the 53-year-old helicopter had to be scrapped.

It happened after the aircraft was shipped to Marchwood from the Falklands Islands, where it had spent the previous four years.

A report published by the Air Accident Investigation Branch (AAIB) says the incident stemmed from mechanical issues caused by the helicopter being inactive during its voyage.

The report also blames the failure to carry out a safety inspection which would have revealed the fault.

"Upon arrival at the helicopter the co-pilot performed the external checks while the commandeer commenced the internal checks. Two of the operator's engineers were also in attendance and remained outside the helicopter throughout.

"As the helicopter took off it pitched nose-down, striking the ground before coming to rest on its landing gear.

"Despite the co-pilot being slightly dazed he commenced the emergency shutdown checklist and called to the commander to apply the rotor brake.

“Both pilots then evacuated the helicopter and went to check the engineers were unhurt."

Investigators found that a bearing had seized as a result of corrosion compounded by the aircraft's inactivity during its voyage from the Falklands.

The seizure involved the helicopter's swashplate, which controlled the pitch of its rotor blades.

"The helicopter should have been subject to a safety inspection," says the report. "It is likely that this check, had it been carried out, would have identified the seized swashplate before the flight."

The accident happened on February 1 2018 and involved an aircraft operated by British International Helicopters.

It was about to perform a "hover check" before flying to Bournemouth Airport, where it would have been refuelled before travelling to the operator's base in Cornwall.

Action has now been taken in a bid to prevent any similar accidents occurring in the future.

The AAIB report says the helicopter's manufacturer has highlighted the correct pre-flight procedures which should be carried out after an aircraft has been subject to a long period of inactivity

The helicopter's operator has "reminded" flight crews to carry out more detailed system checks.