Federal Register / Vol. 86, No. 44 / Tuesday, March 9, 2021 / Rules and Regulations 13445 

Issued on February 25, 2021. 

Gaetano A. Sciortino, 

Deputy Director for Strategic Initiatives, 

Compliance & Airworthiness Division, 

Aircraft Certification Service. 

[FR Doc. 2021–04503 Filed 3–8–21; 8:45 am] 

BILLING CODE 4910–13–P 

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. 

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: 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. 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: carol.nguyen@faa.gov. 

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). 


khammond on DSKJM1Z7X2PROD with RULES
13446 Federal Register / Vol. 86, No. 44 / Tuesday, March 9, 2021 / Rules and Regulations 

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

Action Labor cost Parts cost Cost per 

product 

Cost on U.S. 

operators 

TAI of 1st-stage LPC blades .......................... 22 work-hours × $85 per hour = $1,870 ........ $0 $1,870 $194,480 

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

Action Labor cost Parts cost Cost per 

product 

Replace 1st-stage LPC blade ...................................... 0 work-hours × $85 per hour = $0 ............................... $125,000 $125,000 

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 

■ 1. The authority citation for part 39 

continues to read as follows: 

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


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Federal Register / Vol. 86, No. 44 / Tuesday, March 9, 2021 / Rules and Regulations 13447 

§ 39.13 [Amended] 

■ 2. The FAA amends § 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 1ststage 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: ANE-AD-AMOC@

faa.gov. 

(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: 

carol.nguyen@faa.gov. 

(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] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 71 

[Docket No. FAA–2020–0871; Airspace 

Docket No. 20–AGL–32] 

RIN 2120–AA66 

Amendment of Class D and Class E 

Airspace and Revocation of Class E 

Airspace; Muskegon, MI 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule; correction. 

SUMMARY: This action corrects the final 

rule published in the Federal Register 

on January 21, 2021, amending the Class 

D and Class E airspace and revoking the 

Class E airspace designated as an 

extension to Class D and Class E surface 

areas at Muskegon County Airport, 

Muskegon, MI. The word ‘‘Airport’’ was 

inadvertently omitted from the Class E 

surface area airspace legal description 

for Muskegon County Airport. 

DATES: Effective date 0901 UTC, April 

22, 2021. The Director of the Federal 

Register approves this incorporation by 

reference action under 1 CFR part 51, 

subject to the annual revision of FAA 

Order 7400.11 and publication of 

conforming amendments. 

FOR FURTHER INFORMATION CONTACT: 

Jeffrey Claypool, Federal Aviation 

Administration, Operations Support 

Group, Central Service Center, 10101 

Hillwood Parkway, Fort Worth, TX, 

76177; telephone (817) 222–5711. 

SUPPLEMENTARY INFORMATION: 

History 

The FAA published a final rule in the 

Federal Register (86 FR 6243; January 

21, 2021) for FR Doc. 2021–01019 

amending the Class D and Class E 

airspace and revoking the Class E 

airspace designated as an extension to 

Class D and Class E surface areas at 

Muskegon County Airport, Muskegon, 

MI. Subsequent to publication, the FAA 

identified that word ‘‘Airport’’ was 

inadvertently omitted from the Class E 

surface area airspace legal description 

for Muskegon County Airport. This 

action corrects that error. 

Class E airspace designations are 

published in paragraph 6005 of FAA 

Order 7400.11E dated July 21, 2020, and 

effective September 15, 2020, which is 

incorporated by reference in 14 CFR 

71.1. The Class E airspace designations 

listed in this document will be 

subsequently published in the Order. 

Correction to Final Rule 

Accordingly, pursuant to the 

authority delegated to me, Amendment 

of Class D and Class E Airspace and 

Revocation of Class E Airspace; 

Muskegon, MI, published in the Federal 

Register of January 21, 2021 (86 FR 

6243), FR Doc. 2021–01019, is corrected 

as follows: 

§ 71.1 [Amended] 

■ On page 6244, column 2, line 22, 

amend to read, ‘‘. . . County Airport. 

This . . .’’ 

Issued in Fort Worth, Texas, on March 1, 

2021. 

Martin A. Skinner, 

Acting Manager, Operations Support Group 

ATO Central Service Center 

[FR Doc. 2021–04474 Filed 3–8–21; 8:45 am] 

BILLING CODE 4910–13–P 


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