AD 2020-25-04 Retains The Requirements To Perform Repetitive Inspections Of The Engine Upper Bifurcation Nose Fairing Assembly

The FAA is superseding Airworthiness Directive (AD) 2016-24-08 for all RollsRoyce Deutschland Ltd. & Co KG (RRD) RB211-Trent 875-17, RB211-Trent 877-17, RB211-Trent 884-17, RB211-Trent 884B-17, RB211-Trent 892-17, RB211-Trent 892B-17, and RB211-Trent 895-17 model turbofan engines.

AD 2016-24-08 required repetitive inspections of the engine upper bifurcation nose fairing assembly and repair or replacement of any fairing assembly that fails inspection. This AD retains the requirements to perform repetitive inspections of the engine upper bifurcation nose fairing assembly and repair or replacement of any fairing assembly that fails inspection. As a terminating action to these inspections, this AD also requires the modification of the engine upper bifurcation nose fairing assembly. The FAA is issuing this AD to address the unsafe condition on these products. This AD is effective January 8, 2021.

Supplementary Information: The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to supersede AD 2016-24-08, Amendment 39-18725 (81 FR 86567, December 1, 2016) (AD 2016-24-08). AD 2016-24-08 applied to all RR RB211-Trent 875-17, RB211-Trent 877-17, RB211-Trent 884-17, RB211-Trent 884B-17, RB211-Trent 892-17, RB211-Trent 892B-17, and RB211-Trent 895-17 model turbofan engines. The NPRM published in the Federal Register on June 24, 2019 (84 FR 29423). The NPRM was prompted by RRD developing a modification of the engine upper bifurcation nose fairing assembly that terminates the need for repetitive inspections of this part. In the NPRM, the FAA proposed to retain the requirements to perform repetitive inspections of the engine upper bifurcation nose fairing assembly and repair or replacement of any fairing assembly that fails inspection. As a terminating action, in the NPRM the FAA also proposed to require modification of the engine upper bifurcation nose fairing assembly. The FAA is issuing this AD to address the unsafe condition of these products.

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued EASA AD 2018-0088, dated April 18, 2018 (referred to after this as “the MCAI”), to address the unsafe condition on these products.

The MCAI states:

• Inspection of in-service Trent 800 engines identified cracking and/or material release from the upper bifurcation fairing, which mates to the aeroplane thrust reverser upper bifurcation forward fire seal. Both sets of hardware create the engine firewall to isolate the engine compartment fire zone, which is a firewall feature of the aeroplane type design. Damage (missing materials and holes/openings) to the upper bifurcation fairing creates a breach of the engine fire wall, which may decrease the effectiveness of the engine fire detection and suppression systems due to excess fan air entering the engine compartment fire zone. This could delay or prevent the fire detection and suppression system from functioning properly, and can result in an increased risk of prolonged burning, potentially allowing a fire to reach unprotected areas of the engine, strut and wing.
• This condition, if not detected and corrected, could lead to an uncontrolled fire, possibly resulting in damage to, or loss of, the aeroplane.
• To address this potential unsafe condition, RR published the NMSB to provide inspection instructions. Consequently, EASA issued AD 2016-0084 to require repetitive inspections of the upper bifurcation fairing and, depending on findings, accomplishment of applicable corrective action(s).
• Since that [EASA] AD was issued, RR developed modification (mod) 72-J803, which introduces a revised upper bifurcation nose fairing assembly, featuring an additional support bracket assembly at the right hand seal land. RR also published the modification SB to provide instructions for in-service engines. This modification removes the need for repetitive inspections.
• For the reasons described above, this [EASA] AD retains the requirements of EASA AD 2016-0084, which is superseded, and requires a modification, which constitutes terminating action for the repetitive inspections required by this
• [EASA] AD.

You may obtain further information by examining the MCAI in the AD docket at www.regulations.gov by searching for and locating Docket No. FAA-2019-0425.

FMI: www.regulations.gov