[Federal Register Volume 86, Number 44 (Tuesday, March 9, 2021)]
[Rules and Regulations]
[Pages 13445-13447]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-04747]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0136; Project Identifier AD-2021-00188-E; 
Amendment 39-21470; AD 2021-05-51]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, 
PW4084D, PW4090, and PW4090-3 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 2021-05-51, 
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) 493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE, Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 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) 565-0140; email: [email protected]; 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. FAA-2021-0136.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0136; 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) 238-7655; fax: (781) 238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION:

Background

    On February 23, 2021, the FAA issued Emergency AD 2021-05-51 (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.

FAA's 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-
112-A72-268, Revision No. 7, dated 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 553(b)(3)(B) 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 553(d) 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 2021-05-51, 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 777-222 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. 553(b)(3)(B).

[[Page 13446]]

    In addition, the FAA finds that good cause exists pursuant to 5 
U.S.C. 553(d) for making this amendment effective in less than 30 days, 
for the same reasons the FAA found good cause to forego notice and 
comment.

Comments Invited

    The FAA invites you to send any written data, views, or arguments 
about this final rule. Send your comments to an address listed under 
ADDRESSES. Include the docket number FAA-2021-0136 and Project 
Identifier AD-2021-00188-E at the beginning of your comments. The most 
helpful comments reference a specific portion of the final rule, 
explain the reason for any recommended change, and include supporting 
data. The FAA will consider all comments received by the closing date 
and may amend this final rule because of those comments.
    Except for Confidential Business Information (CBI) as described in 
the following paragraph, and other information as described in 14 CFR 
11.35, the FAA will post all comments received, without change, to 
https://www.regulations.gov, including any personal information you 
provide. The agency will also post a report summarizing each 
substantive verbal contact received about this final rule.

Confidential Business Information

    CBI is commercial or financial information that is both customarily 
and actually treated as private by its owner. Under the Freedom of 
Information Act (FOIA) (5 U.S.C. 552), CBI is exempt from public 
disclosure. If your comments responsive to this AD contain commercial 
or financial information that is customarily treated as private, that 
you actually treat as private, and that is relevant or responsive to 
this AD, it is important that you clearly designate the submitted 
comments as CBI. Please mark each page of your submission containing 
CBI as ``PROPIN.'' The FAA will treat such marked submissions as 
confidential under the FOIA, and they will not be placed in the public 
docket of this AD. Submissions containing CBI should be sent to Carol 
Nguyen, Aviation Safety Engineer, ECO Branch, FAA, 1200 District 
Avenue, Burlington, MA 01803. Any commentary that the FAA receives 
which is not specifically designated as CBI will be placed in the 
public docket for this rulemaking.

Regulatory Flexibility Act

    The requirements of the Regulatory Flexibility Act (RFA) do not 
apply when an agency finds good cause pursuant to 5 U.S.C. 553 to adopt 
a rule without prior notice and comment. Because FAA has determined 
that it has good cause to adopt this rule without prior notice and 
comment, RFA analysis is not required.

Costs of Compliance

    The FAA estimates that this AD affects 104 engines installed on 
airplanes of U.S. registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
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                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
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TAI of 1st-stage LPC blades...........  22 work-hours x $85 per               $0          $1,870        $194,480
                                         hour = $1,870.
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    The FAA estimates the following costs to do any necessary 
replacement that would be required based on the results of the 
inspection. The agency has no way of determining the number of aircraft 
that might need this replacement:

                                               On-Condition Costs
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                                                                                                     Cost per
                    Action                                 Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replace 1st-stage LPC blade...................  0 work-hours x $85 per hour = $0        $125,000        $125,000
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Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs 
describes in more detail the scope of the Agency's authority.
    The FAA is issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: General requirements. 
Under that section, Congress charges the FAA with promoting safe flight 
of civil aircraft in air commerce by prescribing regulations for 
practices, methods, and procedures the Administrator finds necessary 
for safety in air commerce. This regulation is within the scope of that 
authority because it addresses an unsafe condition that is likely to 
exist or develop on products identified in this rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect on the States, 
on the relationship between the national government and the States, or 
on the distribution of power and responsibilities among the various 
levels of government.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866, and
    (2) Will not affect intrastate aviation in Alaska.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

[[Page 13447]]

Sec.  39.13   [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive:

2021-05-51 Pratt & Whitney Division: Amendment 39-21470; Docket No. 
FAA-2021-0136; Project Identifier AD-2021-00188-E.

(a) Effective Date

    This airworthiness directive (AD) is effective without actual 
notice on March 24, 2021. Emergency AD 2021-05-51, issued on 
February 23, 2021, which contained the requirements of this 
amendment, was effective with actual notice.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Pratt & Whitney Division (PW) PW4074, 
PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 model 
turbofan engines, with a 1st-stage low-pressure compressor (LPC) 
blade, with part number 52A241, 55A801, 55A801-001, 55A901, 55A901-
001, 56A201, 56A201-001, or 56A221, installed.

(d) Subject

    Joint Aircraft System Component (JASC) Code 7230, Turbine Engine 
Compressor Section.

(e) Unsafe Condition

    This AD was prompted by an in-flight failure of a 1st-stage LPC 
blade on a PW4077 model turbofan engine resulting in an engine fire 
during flight. The FAA is issuing this AD to prevent failure of the 
1st-stage LPC blades. The unsafe condition, if not addressed, could 
result in 1st-stage LPC blade release, damage to the engine, and 
damage to the airplane.

(f) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.

(g) Required Actions

    (1) Before further flight, perform a thermal acoustic image 
(TAI) inspection of the 1st-stage LPC blades for cracks using a 
method approved by the FAA.
    Note 1 to paragraph (g)(1): Vendors that have an FAA-approved 
TAI inspection are listed in the Vendor Services Section of Pratt & 
Whitney Alert Service Bulletin PW4G-112-A72-268, Revision No. 7, 
dated September 6, 2018.
    (2) If any 1st-stage LPC blade fails the inspection required by 
paragraph (g)(1) of this AD, remove the blade from service and 
replace with a part eligible for installation before further flight.

(h) Definition

    For the purpose of this AD, a ``part eligible for installation'' 
is a 1st-stage LPC blade that passed the inspection required by 
paragraph (g)(1) of this AD.

(i) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, ECO Branch, FAA, has the authority to approve 
AMOCs for this AD, if requested using the procedures found in 14 CFR 
39.19. In accordance with 14 CFR 39.19, send your request to your 
principal inspector or local Flight Standards District Office, as 
appropriate. If sending information directly to the manager of the 
certification office, send it to the attention of the person 
identified in Related Information. You may email your request to: 
[email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(j) Related Information

    For more information about this AD, contact Carol Nguyen, 
Aviation Safety Engineer, ECO Branch, FAA, 1200 District Avenue, 
Burlington, MA 01803; phone: (781) 238-7655; fax: (781) 238-7199; 
email: [email protected].

(k) Material Incorporated by Reference

    None.

    Issued on March 3, 2021.
Gaetano A. Sciortino,
Deputy Director for Strategic Initiatives, Compliance & Airworthiness 
Division, Aircraft Certification Service.
[FR Doc. 2021-04747 Filed 3-8-21; 8:45 am]
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