Airworthiness Directive · Amendment 39-18090 · Rolls-Royce Corporation Turboprop and Turboshaft Engines
Rolls-Royce Corporation Turboprop and Turboshaft Engines
Superseded. A later AD replaced this one: AD 2017-18-14. Comply with the one in force.
This AD applies to Rolls-Royce Corporation (RRC) 250-B17, -B17B, -B17C, -B17D, -B17E, -B17F, -B17F/1, -B17F/2 turboprop engines; and 250-C20, -C20B, -C20F, -C20J, -C20R, -C20R/1, -C20R/2, -C20R/4, -C20S, and -C20W turboshaft engines; with either a 3rd-stage turbine wheel, part number (P/N) 23065818, or a 4th-stage turbine wheel, P/N 23055944, installed.
We are superseding airworthiness directive (AD) 2012-14-06 for certain Rolls-Royce Corporation (RRC) 250-C20, -C20B, and -C20R/2 turboshaft engines. AD 2012-14-06 required a one-time visual inspection and fluorescent-penetrant inspection (FPI) on certain 3rd-stage and 4th-stage turbine wheels for cracks in the turbine blades. This new AD replaces the one-time visual inspection and FPI with repetitive visual inspections and FPIs. This AD also adds certain engine models to the applicability. This AD was prompted by the determination that the one- time inspections required by AD 2012-14-06 should be changed to repetitive inspections. We are issuing this AD to prevent failure of 3rd-stage and 4th-stage turbine wheel blades, which could cause engine failure and damage to the aircraft.
(1) Within 1,750 HSLI, remove the affected turbine wheels and perform a visual inspection and a fluorescent-penetrant inspection (FPI) on the removed turbine wheels for cracks at the trailing edge of the turbine blades near the fillet at the rim.
(2) Any time the power turbine is disassembled, perform a visual inspection and an FPI on the affected turbine wheels for cracks at the trailing edge of the turbine blades, near the fillet at the rim.
(3) Thereafter, re-inspect every 1,750 HSLI.
(4) Do not return to service any turbine wheels that have cracks detected.
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.
Engines
