Mechanic had to free helicopter landing gear, report says
A helicopter carrying oil workers had to hover with its nose in the air at an airport in Shetland to allow a mechanic to release the landing gear.
The helicopter, with two crew and 19 passengers on board, was on approach to Scatsta Airport from the Magnus platform when the incident happened.
The Air Accidents Investigation Branch said the S-92's landing gear was found to be covered in oily, dirty deposits.
However, it could not identify the exact cause of the failure.
The AAIB report said the incident, on 29 January, highlighted issues with procedures on how to deal with such an emergency, which had now been addressed.
It was found that the automatic nose wheel self-centring mechanism of the Sikorsky helicopter had not operated, causing the nose wheels to jam in their bay.
The crew sought advice from engineers over the radio and then hovered the helicopter over the runway apron, with its back wheels on the ground and nose held in the air.
An engineer then checked the nose landing gear (NLG) and released it with a lever, allowing the helicopter to land.
Passengers were briefed before the manoeuvre and emergency services were on standby throughout.
The cause of the failure was not determined, but the AAIB said the operator had taken three safety actions, including updated guidance for engineers and a review of emergency operations procedures.
The helicopter was removed from service and the landing gear was replaced.
The AAIB report said: "The exact cause of the failure of the NLG to centre the nose wheels during retraction could not be determined. However, the operator has taken steps to inform its staff of a potential cause identified in previous cases by the manufacturer.
"The incident has also highlighted a discontinuity in the operator's emergency procedures, which have also been addressed."