AAIB investigation to Boeing 767-322, N657UA

Smoke and haze in the cabin due to a cabin lighting wiring harness fault, London Heathrow Airport, 29 April 2019.


The aircraft was climbing through 15,000 feet after departure from London Heathrow (LHR) when it was reported that an electrical burning smell, smoke and haze, was apparent in the cabin. The crew obtained clearance to return to LHR and, after carrying out the ‘smoke and fumes’ checklist, the problem was alleviated. The aircraft landed without further incident. A small section of wiring within the cabin ceiling lighting harness was found to have been the source of the smoke and fumes. Damage to the harness was found to have been caused by an electrical event leading to arcing between two of the insulated wires within the harness. The exact nature of this event could not be determined.

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Boeing 767-322, N657UA 10-19

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Published 10 October 2019