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Federal Register / Vol. 86, No. 44 / Tuesday, March 9, 2021 / Rules and Regulations Issued on February 25, 2021.
Gaetano A. Sciortino, Deputy Director for Strategic Initiatives, Compliance & Airworthiness Division, Aircraft Certification Service.
FR Doc. 202104503 Filed 3821; 8:45 am BILLING CODE 491013P

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration 14 CFR Part 39
Docket No. FAA20210136; Project Identifier AD202100188E; Amendment 3921470; AD 20210551
RIN 2120AA64

Airworthiness Directives; Pratt &
Whitney Division Turbofan Engines Federal Aviation Administration FAA, DOT.
ACTION: Final rule; request for comments.
AGENCY:

The FAA is adopting a new airworthiness directive AD for certain Pratt & Whitney Division PW PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW40903
model turbofan engines. This AD was prompted by the in-flight failure of a 1st-stage low-pressure compressor LPC
blade on a PW4077 model turbofan engine resulting in an engine fire during flight. This AD requires performing a thermal acoustic image TAI inspection for cracks in certain 1st-stage LPC
blades and removal of those blades that fail inspection. The FAA previously sent an emergency AD to all known U.S.
owners and operators of these engines and is now issuing this AD to address the unsafe condition on these products.
DATES: This AD is effective March 24, 2021. Emergency AD 20210551, issued on February 23, 2021, which contained the requirements of this amendment, was effective with actual notice.
The FAA must receive comments on this AD by April 23, 2021.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
Federal eRulemaking Portal: Go to https www.regulations.gov. Follow the instructions for submitting comments.
Fax: 202 4932251.
Mail: U.S. Department of Transportation, Docket Operations, M30, West Building Ground Floor, Room W12140, 1200 New Jersey Avenue SE, Washington, DC 20590.
Hand Delivery: Deliver to Mail address above between 9 a.m. and 5

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SUMMARY:

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p.m., Monday through Friday, except Federal holidays.
For service information identified in this final rule, contact Pratt & Whitney Division, 400 Main Street, East Hartford, CT 06118; phone: 860 5650140;
email: help24@pw.utc.com; website:
https fleetcare.pw.utc.com. You may view this service information at the FAA, Airworthiness Products Section, Operational Safety Branch, 1200 District Avenue, Burlington, MA 01803. For information on the availability of this material at the FAA, call 781 238
7759. It is also available at https
www.regulations.gov by searching for and locating Docket No. FAA2021
0136.
Examining the AD Docket You may examine the AD docket at https www.regulations.gov by searching for and locating Docket No.
FAA20210136; 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 final rule, any comments received, and other information. The street address for Docket Operations is listed above.
FOR FURTHER INFORMATION CONTACT:
Carol Nguyen, Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, Burlington, MA 01803; phone:
781 2387655; fax: 781 2387199;
email: carol.nguyen@faa.gov.
SUPPLEMENTARY INFORMATION:
Background On February 23, 2021, the FAA issued Emergency AD 20210551 the emergency AD, which requires performing a TAI inspection for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. The FAA sent the emergency AD to all known U.S. owners and operators of these engines. That action was prompted by the in-flight failure of a 1st-stage LPC blade on a PW4077 model turbofan engine resulting in an engine fire during flight.
This condition, if not addressed, could result in 1st-stage LPC blade release, damage to the engine, and damage to the airplane.
FAAs Determination The FAA is issuing this AD because the agency evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.
Related Service Information The FAA reviewed Pratt & Whitney Alert Service Bulletin ASB PW4G
112A72268, Revision No. 7, dated
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September 6, 2018. The ASB describes procedures for performing TAI
inspections of 1st-stage LPC blades.
AD Requirements This AD requires performing a TAI
inspection for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection.
Interim Action The FAA considers this AD to be an interim action. The FAA anticipates that further AD action will follow.
Justification for Immediate Adoption and Determination of the Effective Date Section 553b3B of the Administrative Procedure Act APA 5
U.S.C. 551 et seq. authorizes agencies to dispense with notice and comment procedures for rules when the agency, for good cause, finds that those procedures are impracticable, unnecessary, or contrary to the public interest. Under this section, an agency, upon finding good cause, may issue a final rule without providing notice and seeking comment prior to issuance.
Further, section 553d of the APA
authorizes agencies to make rules effective in less than thirty days, upon a finding of good cause.
An unsafe condition exists that required the immediate adoption of Emergency AD 20210551, issued on February 23, 2021, to all known U.S.
owners and operators of these engines.
The FAA found that the risk to the flying public justified waiving notice and comment prior to adoption of this rule. On February 20, 2021, a United Airlines Boeing Model 777222
airplane, equipped with two PW4077
model turbofan engines, on a flight from Denver, Colorado to Honolulu, Hawaii, experienced a 1st-stage LPC blade failure on the number 2 engine. This engine failure resulted in the separation of the fan inlet and cowling from the airplane, an engine fire, and damage to the airplane. The airplane was forced to return to the airport of departure. The unsafe condition, caused by the failure of the 1st-stage LPC blade, could result in 1st-stage LPC blade release, damage to the engine, and damage to the airplane.
The FAA considers inspection and removal of those blades that fail inspection to be an urgent safety issue.
Inspection of the 1st-stage LPC blade for cracks must be accomplished before further flight after the effective date of this AD. These conditions still exist, therefore, notice and opportunity for prior public comment are impracticable and contrary to the public interest pursuant to 5 U.S.C. 553b3B.

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