Helicopter spun after 'losing total tail rotor control'

Damage was caused as a S92 helicopter was landing last month

A spinning helicopter left gouge marks on a North Sea platform after total loss of control of the tail rotor due to internal damage, investigators have said.

The S92 incident happened on the West Franklin Platform last month.

An Air Accidents Investigation Branch (AAIB) bulletin has revealed when panels were removed it was immediately clear a tail rotor piston was damaged.

The helicopter came to rest having rotated more than 180 degrees.

No-one was injured.

Sikorsky S92s began undergoing specific tail rotor safety checks worldwide on Tuesday due to the incident.

Gouge marks were left on the deck of the platform

The bulletin said a bearing was in a "severely distressed condition", and initial findings were the failure had been "rapid".

Further disassembly founds "signs of severe overheating with extreme wear".

The report said there was a "consequential total loss of control of the tail rotor".

Initial investigations show the S92 helicopter spun 187 degrees when landing on the West Franklin platform.

The AAIB said the incident took place on 28 December and it was made aware of it on 5 January.

Its investigation is continuing.

A phased return to service of the fleet after the checks got under way on Tuesday, although bad weather was limiting flights on Wednesday.