All helicopter operators and maintenance providers.
The purpose of this CAN is to notify helicopter operators and maintenance providers of two recent occurrences reported to CAA of helicopter windows departing the aircraft doors during the first flight following window installation.
The reported events were from different operators, maintenance providers and aircraft types (i.e. MD500 and AS350), and appear to be unrelated.
In both cases, the window departed the helicopter during the first flight following window installation to a ‘new’ door. The incidents occurred while the aircraft were flying straight and level with the doors closed throughout.
According to both reports, the window remained intact during departure from the aircraft doors, and the crew received no warning of the pending window failure.
Neither window was recovered for examination. In one case the window seal remained with the aircraft door allowing the operator to confirm airworthiness of the window seal.
In both events the failed window was a used serviceable part, which had previously been fitted to a different aircraft door, on a different aircraft.
Maintenance providers installing used serviceable aircraft windows are advised to pay particular attention to the aircraft maintenance manual instructions regarding the necessary minimum aircraft window size and any associated window to door frame overlap requirements.
Where a window has previously been trimmed to fit an aircraft door, it is entirely possible that it will then be undersized for another aircraft door.
Operators are reminded of the flight safety risk associated with parts departing an aircraft. In both reported events, operators were fortunate that the departing windows fell clear of the helicopter, and that there were no loose items present in the cabin, which could have been drawn out of the compromised door.
CAA requests that operators and maintenance providers report any issues with aircraft windows, or doors (including departure of windows) and inadvertent opening of doors to CAA. Please report findings to CAA by completing a CA005 Defect Report form.
The form can be obtained from: aviation.govt.nz/assets/forms/CA005D_Form.pdf The completed form can be emailed to the CAA at: ca005@caa.govt.nz
Any questions can be directed to: warren.hadfield@caa.govt.nz
CAA will continue to monitor failures of aircraft windows and doors and will update this CAN accordingly.
