Airworthiness Directive · Amendment 39-22040 · Engine controls
Honeywell International, Inc. (Type Certificate Previously Held by AlliedSignal, Inc. and Textron Lycoming) Turboshaft Engines
This AD applies to Honeywell International, Inc. (Type Certificate previously held by AlliedSignal, Inc. and Textron Lycoming) T5311A, T5311B, T5313B, T5317A, T5317A-1, T5317B, T5317BCV, and former military T53-L-11, T53-L-11A, T53-L-11B, T53-L-11C, T53-L-11D, T53-L-11A S/SA, T53-L-13B, T53-L-13B S/SA, T53-L-13B S/SB, and T53-L-703 model turboshaft engines.
The FAA is superseding Airworthiness Directive (AD) 2002-03- 01, which applied to certain Honeywell International, Inc. (Honeywell) T53 model turboshaft engines. AD 2002-03-01 required initial and repetitive special vibration tests of the engine and, if necessary, replacement with a serviceable reduction gearbox assembly, or a serviceable engine before further flight. This AD was prompted by reports of tachometer drive spur gear failure, resulting in potential engine overspeed, loss of power turbine speed (N2) instrument panel indication, and hard landings. This AD requires initial and repetitive special vibration tests of the engine and, depending on the results, replacement of either the reduction gearbox assembly or the engine. The FAA is issuing this AD to address the unsafe condition on these products.
(1) Within 100 flight hours (FHs) after the effective date of this AD, or before further flight for a newly installed engine or newly installed reduction gearbox assembly, perform an initial special vibration test of the engine using the service information, as applicable to the engine model, listed in Table 1 to paragraph (g)(1) of this AD.
(2) Thereafter, within the following compliance times, perform repetitive special vibration tests of the engine:
(i) For engines that have tachometer drive spur gear part number (P/N) 1-070-062-04 installed, perform a repetitive special vibration test before exceeding 500 FHs since the last special vibration test.
(ii) For engines that have tachometer drive spur gear P/N 1-070-062-06 installed, perform a repetitive special vibration test before exceeding 1,000 FHs since the last special vibration test.
(3) If, during any special vibration test required by paragraph (g)(1) or (2) of this AD, an engine exceeds the 0.2 inches per second (IPS) limit for any peak RPM/frequency bands, before further flight, remove the reduction gearbox assembly or the engine from service.
The reporting requirements in the Accomplishment Instructions, paragraph 3.A. or paragraph 11.F, of the service information, as applicable to the engine model, listed in Table 1 to paragraph (g)(1) of this AD, are not required by this AD.
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.
