AAIB investigation to Boeing 737-36E Freighter, TF-BBF

APU bleed air duct leak, East Midlands Airport, Leicestershire, 3 February 2017.


Shortly prior to engine start the aircraft suffered an APU bleed air duct leak in the rear equipment bay. The leaking bleed air heated corrosion-inhibitor material in the rear equipment bay, resulting in scorching and the release of smoke within the main cargo deck. The flight crew shut the APU down. The cause of the bleed air leak was a failed V-band clamp that had fractured due to stress corrosion cracking. The operator is currently replacing V-band clamps at the failure location on its fleet of 737-300 and 737 400 freighter aircraft.

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Boeing 737-36E Freighter, TF-BBF 12-17

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Glossary of abbreviations

Published 14 December 2017