Airworthiness Directive 05-6778
one-timeAirworthiness Directives; Hartzell Propeller Inc. (Formerly TRW Hartzell Propeller) Models HC-B3TN-2, HC-B3TN-3, HC-B3TN-5, HC-B4TN-3, HC-B4TN-5, HC-B4MN-5, and HC-B5MP-3 Turbopropellers
What this AD requires
The FAA is revising an existing airworthiness directive (AD), that is applicable to Hartzell Propeller Inc. (formerly TRW Hartzell Propeller) models HC-B3TN-2, HC-B3TN-3, HC-B3TN-5, HC-B4TN-3, HC-B4TN- 5, HC-B4MN-5, and HC-B5MP-3 turbopropellers. That AD requires, before further flight, that all new propellers being installed and all serviceable propellers being reinstalled, are attached using part number (P/N) B-3339 bolts and P/N A-2048-2 washers, and that the bolts are properly torqued. That AD also requires a onetime torque-check of P/N A-2047 bolts that are already installed through propellers and replacement of those bolts if necessary, with P/N B-3339 bolts and P/N A-2048-2 washers. This AD requires the same actions, and includes the use of other equivalent FAA-approved serviceable bolts and washers. This AD results from the need to make nonsubstantive wording changes and additions to clarify that terminating action is achieved by attaching propellers with P/N B-3339 bolts and P/N A-2048-2 washers or other equivalent FAA-approved serviceable bolts and washers, to the engine flange, as instructed in the compliance section of this AD. We are issuing this AD to preclude propeller attaching bolt failures or improperly secured propellers, which could lead to separation of the propeller from the airplane.
Which aircraft AD 05-6778 applies to
Applicability text excerpt references "the preceding applicability provision" for the specific propeller models covered (not captured in this text slice; propeller identity inferred from Hartzell-format lubricant/part numbers in the text). AD requires proper installation of propeller attaching bolts/washers and, for turbopropellers presently installed with P/N A-2047 attaching bolts, a torque check within 300 hours TIS with replacement by P/N B-3339 bolts and P/N A-2048-2 washers (or FAA-approved equivalents) if under-torque.
Whether AD 05-6778 actually applies to your aircraft (by serial and installed parts) and whether it’s already complied with comes from that aircraft’s records.
How AD compliance is recorded
A valid compliance record (14 CFR 43.9) states:
Tailplate reads a tail number’s logbooks and matches every applicable AD — including this one — to its compliance evidence, with recurring next-due dates computed.
Look up a tail number →Read the full directive (Federal Register)Applicability is derived from the FAA directive corpus and is advisory, not a legal airworthiness determination. Compliance is established only from an aircraft’s actual records.