Airworthiness Directive · Amendment 39-8921 · The Boeing Company Airplanes
The Boeing Company Airplanes
This AD applies to The Boeing Company 767-200 Series, 767-300 Series.
The models as the FAA's AD index lists them. The serial ranges, installed parts and exceptions are in the AD itself: read it at the FAA.
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 767-200 and 767-300 series airplanes. This action requires repetitive inspections of the pumping unit assembly on the override and jettison fuel boost pump assemblies to detect looseness of the screws that attach the inlet diffuser assembly to the pumping unit housing, and repair or replacement of the pumping unit assembly with a serviceable assembly, if necessary. For certain airplanes, this AD also provides for deactivation of the center wing fuel tank as an alternative to the repetitive inspections. This amendment is prompted by reports of failures of the override and jettison fuel pumps due to damage to impeller units and pumping unit housings caused by loose diffuser rings in the fuel pump assemblies of these airplanes. During dry fuel operation, a loose diffuser ring may cause metal-to-metal contact. The actions specified in this AD are intended to prevent the generation of sparks and a potential ignition source inside the fuel tank caused by metal-to-metal contact during dry fuel pump operation.
