Airworthiness Directive · Amendment 39-14137 · [Hoffmann Propeller GmbH & Co KG Models HO-V343 and HO-V343K Propellers]
[Hoffmann Propeller GmbH & Co KG Models HO-V343 and HO-V343K Propellers]
This AD applies to Hoffmann Propeller GmbH & Co KG (Hoffmann Propeller) models HO-V343 and HO-V343K propellers. These propellers are installed on, but not limited to, general aviation airplanes possibly having an FAA-approved Supplemental Type Certificate.
The FAA is superseding an existing airworthiness directive (AD) for Hoffmann Propeller GmbH & Co KG Models HO-V343 and HO-V343K propellers. That AD currently requires initial and repetitive visual inspections of propeller blades for blade shake and blade nut preload. That AD also requires initial and repetitive eddy current inspections of blade hubs for damage and cracks. This AD requires an ultrasonic inspection of the propeller hub and an eddy current inspection of the propeller hub if any cracks are discovered during ultrasonic inspection. Additionally, this AD requires sending a hub inspection report to the manufacturer. This AD also requires replacement of the propeller if any signs of blade shake, cracks, or other damage to the propeller hub outside serviceable limits are detected during the inspections. This AD results from the discovery of a propeller blade separation due to a possible hub failure. We are issuing this AD to prevent propeller hub failure and blade separation due to an unknown root cause, leading to damage and possible loss of control of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
For all propellers, perform an inspection for propeller blade shake at each preflight inspection. If you have any blade shake, replace the propeller assembly.
For all propellers, use paragraph 2.1 of the Accomplishment Instructions of Hoffmann Propeller Service Instruction (SI) No. 61-10-05 SI E 4D, dated March 16, 2005, to inspect blade nut preload at the following intervals:
(1) Before further flight after the effective date of this AD.
(2) Inspect within 50 flight hours (FH) time-since-initial inspection.
(3) Thereafter, inspect within 100 FH time-since-last inspection (TSLI).
(h) If the blade nut preload inspection shows a loss of the blade nut preload, before further flight perform an ultrasonic inspection (UI) as specified in paragraph (i) of this AD.
(i) If the propeller meets any of the conditions detailed in subparagraphs (1) and (2) below, before further flight, calibrate the ultrasonic probe and conduct an ultrasonic inspection of the propeller hub blade retaining threads for cracks inserting the probe in each hub arm bore. Use paragraph 2.2 of the Accomplishment Instructions of Hoffmann Propeller Service Instruction (SI) No. 61-10-05 SI E 4D, dated March 16, 2005, to perform the inspection.
(1) The propeller hub has accumulated 500 or more FH time-since-new (TSN), and has not been inspected using an ultrasonic or eddy current method, or
(2) The blade nut preload and final retorque force inspection called for in paragraph (g) of this AD indicates a loss of blade retention nut preload torque below allowable limits.
(j) For propellers with hubs that have accumulated 500 or more FH TSN repeat the ultrasonic inspection within intervals of 100 FH TSLI.
If the ultrasonic inspection shows any signs of cracks or damage, conduct an eddy current inspection of the threads in the hub bore before further flight. Use paragraph 2.3 of the Accomplishment Instructions of Hoffmann Propeller Service Instruction (SI) No. 61-10-05 SI E 4D, dated March 16, 2005, to perform this inspection.
(l) If you find any signs of cracks or damage to the propeller hub outside serviceable limits during the eddy current inspection, repair or replace the propeller before further flight.
Previous credit is allowed for propeller hub inspections performed under the requirements of AD 2004-18-01.
Complete Hoffmann Hub Inspection Report HO-V343 detailing any blade shake, blade nut preload history and final blade nut retorque force and forward report to Hoffmann Propeller GmbH & Co KG, Küpferlingstraße 9, D-83022 Rosenheim, Germany, telephone ++49-(0)8031-1878-0; fax ++49-(0)8031-1878-78.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Propellers
