2018-20715. Airworthiness Directives; CFM International S.A. Turbofan Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM); withdrawal.

SUMMARY:

The FAA withdraws an NPRM that published on August 25, 2017 regarding an unsafe condition involving certain CFM International CFM56-7B turbofan engines. The agency subsequently determined that the identified unsafe condition was not adequately addressed by the proposed actions and published two final rules that adequately address the identified unsafe condition.

DATES:

Effective September 26, 2018, the FAA withdraws the NPRM published at 82 FR 40516, on August 25, 2017.

ADDRESSES:

You may examine the Airworthiness Directive (AD) docket on the internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2017-0313; or in person at Docket Operations between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this action, the NPRM (82 FR 40516, August 25, 2017) the regulatory evaluation, any comments received, and other information. The address for Docket Operations (phone: [phone]) is U.S. Department of Transportation, Docket Operations, M 30, West Building Ground Floor, Room W12 140, 1200 New Jersey Avenue SE, Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT:

Christopher McGuire, Aerospace Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington MA, 01803; phone: [phone]; fax: [phone]; email: [e-mail].

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued an NPRM proposing to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) with an AD applicable to certain CFM International CFM56-7B turbofan engines. The proposed AD would have required a one-time ultrasonic inspection (USI) or eddy current inspection (ECI) of certain fan blades and, if they fail the inspection, their replacement with parts eligible for installation. The proposed action was prompted by a report of an in-flight fan blade failure and uncontained forward release of debris on a CFM56-7B turbofan engine.

Since issuing the NPRM, the FAA determined that the identified unsafe condition was not adequately addressed by the actions proposed in the NPRM. Therefore, the FAA published two final rules, AD 2018-09-51 (83 FR 23794, May 23, 2018) and AD 2018-10-11 (83 FR 22836, May 17, 2018) to require initial and repetitive USI or ECI of certain fan blades, and to reduce the compliance time for the inspection of certain fan blades. The unsafe condition identified in the NPRM is now addressed by AD 2018-09-51 (effective June 7, 2018) and AD 2018-10-11 (effective June 1, 2018).

The Withdrawal

Accordingly, the FAA withdraws the NPRM (Docket No. FAA-2017-0313, Product Identifier 2017-NE-11-AD) published at 82 FR 40516 on August 25, 2017.

Issued in Burlington, Massachusetts, on September 17, 2018.

Robert J. Ganley,

Manager, Engine and Propeller Standards Branch, Aircraft Certification Service.