2026-16502Proposed RuleWallet

Rolls-Royce Engines Face More Borescope Prodding from FAA

Published Date: 8/13/2026

Proposed Rule

Summary

The FAA proposes to supersede Airworthiness Directive (AD) 2025-26-03, which applies to certain Rolls-Royce Deutschland Ltd & Co KG (RRD) Model Trent 1000-A, Trent 1000-AE, Trent 1000-C, Trent 1000- CE, Trent 1000-D, Trent 1000-E, Trent 1000-G, and Trent 1000-H engines. AD 2025-26-03 requires repetitive borescope inspections (BSIs) of the high-pressure compressor (HPC) rear drum cavity and cavities between each HPC rotor disc, and depending on the results of inspection, removal of the engine from service. AD 2025-26-03 also allows an alternative method of complying with the repetitive BSIs if certain actions are accomplished. Since the FAA issued AD 2025-26-03, RRD published updated service material with a revised bolting arrangement at the HPC rotor shaft to high-pressure turbine (HPT) rotor disc interface to address the unsafe condition. This proposed AD would require repetitive BSIs of the HPC rear drum cavity and cavities between each HPC rotor disc, and depending on the results of inspection, removal of the engine from service. This proposed AD would also allow an alternative method of complying with BSIs if certain actions are accomplished, and require modification of the bolting arrangement as a terminating action for the repetitive BSIs. The FAA is proposing this AD to address the unsafe condition on these products.

Analyzed Economic Effects

4 provisions identified: 0 benefits, 4 costs, 0 mixed.

Repetitive borescope inspections required

The FAA proposes repetitive borescope inspections (BSIs) of the high-pressure compressor (HPC) rear drum cavity and cavities between each HPC rotor disc, and engines may need removal from service depending on inspection results. The FAA estimates a BSI takes 8 work-hours at $85/hour = $680 per engine and an engine health monitoring service of 1 work-hour at $85 = $85 per engine; the NPRM estimates these actions affect 6 engines on U.S. registry (total BSI cost on U.S. operators $4,080; health monitoring total $510).

Bolting modification as terminating action

The proposed AD would require modifying the bolting arrangement at the HPC rotor shaft to the HPT rotor disc interface as a terminating action for the repetitive BSIs. The FAA estimates the modification takes 5 work-hours at $85/hour plus $4,000 in parts = $4,425 per engine, with an estimated total cost on U.S. operators of $26,550 for 6 engines.

Potential on-condition repair very costly

If inspections find damage requiring repair or replacement of the HPC mini-disc anti-rotation block, the FAA estimates on-condition costs up to $650,680 per engine (up to $650,000 parts plus up to 8 work-hours at $85/hour = $680). The agency cannot predict how many engines will require these repairs.

Applies to specified Trent 1000 engine models

The proposed AD applies to Rolls-Royce Deutschland Ltd & Co KG Model Trent 1000-A, Trent 1000-AE, Trent 1000-C, Trent 1000-CE, Trent 1000-D, Trent 1000-E, Trent 1000-G, and Trent 1000-H engines. The FAA estimates this AD would affect 6 engines installed on airplanes of U.S. registry.

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Key Dates

Published Date
Comments Due
8/13/2026
9/28/2026

Department and Agencies

Department
Independent Agency
Agency
Transportation Department
Federal Aviation Administration
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