Airworthiness Directive · Amendment 39-13346 · Rolls-Royce plc RB211-524 Series Turbofan Engines
Rolls-Royce plc RB211-524 Series Turbofan Engines
This AD applies to the Rolls-Royce plc (RR) engines in the following Table 1, with the dedicated generator rotor assembly, part number (P/N) UL39102, adaptor casing P/N UL26756 or UL26729, on the high speed gearbox (HSGB), and bearings P/N UL21029 installed. Table 1.--Affected Engines and Compliance Times Comply after the effective date of this Engine model Engine serial numbers AD RB211-524G2-19........................ Before SN 13793............... Within 62 months. RB211-524G2-T-19...................... All SNs....................... Within 62 months. RB211-524G3-19........................ Before SN 13793............... Within 62 months. RB211-524G3-T-19...................... All SNs....................... Within 62 months. RB211-524H2-19........................ Before SN 13793............... Within 62 months. RB211-524H2-T-19...................... All SNs....................... Within 62 months. RB211-524H-36......................... Before SN 13472............... Within 16 months. RB211-524H-T-36....................... All SNs....................... Within 16 months. These engines are installed on, but not limited to, Boeing 747 and 767 series airplanes.
The FAA is adopting a new airworthiness directive (AD) for certain Rolls-Royce plc (RR) RB211-524 series turbofan engines. This AD requires replacing the dedicated generator rotor assembly, the adaptor casing on the high speed gearbox (HSGB), and bearings with new design parts on certain engines. This AD is prompted by several reports of dedicated generator rotor assembly bearing failures. We are issuing this AD to prevent possible uncommanded engine acceleration with no reaction to throttle movement, which could result in uncontrollable asymmetric engine thrust levels during takeoff or climb.
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
