CASE STUDIES

HELICOPTER CHIP WARNING LIGHT INDICATION

The worst case scenario could have been an in-flight shut down with a Starter/Generator replacement, say around £3500 estimated for the generator.

INTRODUCTION

Helicopter Maintenance on Arrius 2B2. The oil filter was sent in as a result of a chip warning light in June 04 and, after discussions with Turbomeca, the helicopter continued flying until the July 04 when the chip detector activated again. Chips from the Master Chip detector and Gearbox chip detector were forwarded to Spectro.

ACTION/FOLLOW UP

The initial  analysis results were passed to Turbomeca who advised the maintenance company to examine the magnetic seals on the Engine Output shaft, Centrifical Breather shaft (Oil/Air separator) and Starter/Generator shaft. Following the second chip detector activation and subsequent investigation it was found that on the Starter/Generator shaft the carbon face on the seal had worn away/broken off, so it was a direct metal to metal contact.

CONCLUSION:

The initial analysis gave Turbomeca an indication of potential areas of concern and would have cut down the time required for investigation by focusing on only certain items. At what point the seal would have started to leak is difficult to assess. The operator made no comment about the Starter/Generator being covered in oil so it must be assumed that the only item needing replacement was the seal itself. The worst case scenario could have been an in-flight shut down with a Starter/Generator replacement, say around £3500 estimated for the generator.

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Case Studies