EASA 2019-0039

Requires modification of the engine combustion chamber D1 drain assembly P/N that include a new drain route confined to the engine bay only. Prompted by a maintenance inspection that found evidence of head damage to several fairleads that support the engine combustion chamber D1 drain hose. While the heat damage does not impair the structural strength of the fairleads or D1 drain pipe, the drain pipe could transfer so much heat to the nearby fuel system vent pipe that its internal surface temperature would exceed the auto-ignition temperature for fuel. This condition could thus lead to undetected fire ignition in the fuel tank bay, EASA said.