AAIB investigation to Westland Scout AH1, G-CIBW
Loss of door window in flight, West Dean, Salisbury, Wiltshire, 17 September 2020
Summary:
The helicopter was flying straight and level at approximately 100 KIAS when the pilot heard a loud bang. It immediately became apparent that the fixed upper window in the left door had fallen out, leaving the rubber retaining grommet in place. The helicopter was above fields at the time of the event and the pilot carried out a brief airborne search of the area but was unable to locate the window. The helicopter returned to Middle Wallop Airfield without further incident.
The subsequent examination of the door and window frame found that the rubber window retaining grommet had perished. The grommet incorporates ridges and channels designed to attach and hold the window into its frame. Approximately 200 mm of the central ridge on the grommet had separated allowing the window to be ‘loosened by the airflow’, causing it to fall out of its frame. No other damage to the helicopter was reported.
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