Airworthiness Directive · Amendment 39-21109 · Turbine engine compressor section
Rolls-Royce Deutschland Ltd & Co KG (Type Certificate Previously Held by Rolls-Royce plc) Turbofan Engines
This AD applies to Rolls-Royce Deutschland Ltd. & Co KG (RRD) (Type Certificate previously held by Rolls-Royce plc) RB211-535E4-37, RB211-535E4-B-37, RB211-535E4-C-37, and RB-211-535E4-B-75 model turbofan engines except those with fan blades that have all incorporated Rolls-Royce (RR) Service Bulletin (SB) RB.211-72-C946, Revision 4, dated June 22, 2010 (or any earlier revision).
The FAA is superseding Airworthiness Directive (AD) 2008-22-24 for certain Rolls-Royce Deutschland Ltd. & Co KG (RRD) RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4-B-75 model turbofan engines. AD 2008- 22-24 required initial and repetitive ultrasonic inspections (USIs), both on-wing and during overhaul, to detect cracks on the installed low-pressure compressor (LPC) fan blade roots. AD 2008-22-24 also required re-lubrication of the fan blade roots according to accumulated life cycles. This AD retains the requirements of AD 2008-22-24 and extends these requirements to engines operating under additional flight profiles and adds the RB211-535E4-C-37 model turbofan engines to the applicability of this AD. This AD requires initial and repetitive USIs to detect cracks on the installed LPC fan blade roots, both on-wing and at engine overhaul, and replacement of certain blades that exceed the criteria established by the manufacturer. This AD was prompted by small cracks found in the LPC fan blade roots on the concave root flank during an engine overhaul. The FAA is issuing this AD to address the unsafe condition on these products.
(1) For engine models being used in the flight profiles indicated in Table 1 to paragraph (g)(1) of this AD, perform initial and repetitive ultrasonic inspections (USIs) of the affected fan blades in accordance with the Accomplishment Instructions, paragraphs 3.A., 3.B., and 3.C., of RR Alert Non-Modification Service Bulletin (NMSB) RB211-72-AC879, Revision 9, dated April 23, 2018, as follows:
(i) Perform an initial ultrasonic root or surface wave inspection of each LPC fan blade before exceeding the inspection threshold as indicated in Table 1 to paragraph (g)(1) of this AD, or within 30 days after the effective date of this AD, whichever occurs later.
(ii) Thereafter, perform a repetitive ultrasonic root or surface wave inspection of each LPC fan blade at intervals not to exceed engine flight cycles (EFCs) since the previous inspection using the applicable EFCs specified in Table 1 to paragraph (g)(1) of this AD.
(2) For engine models that, after the effective date of this AD, change flight profiles, inspect the affected fan blades before exceeding the initial threshold of the new flight profile or reinspection interval, as applicable, or within 200 EFCs after changing flight profiles, whichever occurs later, without exceeding the previous flight profile initial inspection threshold or reinspection interval.
(3) If, during any inspection required by paragraph (g)(1) or (2) of this AD, any crack is found in the affected fan blades that exceeds the criteria in the Accomplishment Instructions, paragraphs 3.A., 3.B., or 3.C., of RR Alert NMSB RB211-72-AC879, Revision 9, dated April 23, 2018, before the next flight, replace the LPC fan blade with a LPC fan blade eligible for installation.
Modification of any RRD RB211-535E4-37, RB211-535E4-B-37, RB211-535E4-C-37, and RB-211-535E4-B-75 model turbofan engine in accordance with RR SB RB.211-72-C946, Revision 4, dated June 22, 2010, constitutes terminating action to 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.
