Proposed Rule2021-27840
Airworthiness Directives; Pratt & Whitney Division Turbofan Engines
Primary source
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Published
December 28, 2021
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
The FAA proposes to supersede Airworthiness Directive (AD) 2019-03-01 and AD 2021-05-51, which apply to certain Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 model turbofan engines. AD 2019-03-01 requires performing initial and repetitive thermal acoustic image (TAI) inspections for cracks in certain 1st-stage low-pressure compressor (LPC) blades and removal of those blades that fail inspection. AD 2021-05-51 requires performing a one-time TAI inspection for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. Since the FAA issued AD 2019-03-01 and AD 2021-05-51, the manufacturer determined the need to add initial and repetitive ultrasonic testing (UT) inspections of the 1st-stage LPC blades. This proposed AD would require initial and repetitive UT inspections and TAI inspections for cracks in certain 1st-stage LPC blades and removal of those blades that fail inspection. The FAA is proposing this AD to address the unsafe condition on these products.
Full Text
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<title>Federal Register, Volume 86 Issue 246 (Tuesday, December 28, 2021)</title>
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[Federal Register Volume 86, Number 246 (Tuesday, December 28, 2021)]
[Proposed Rules]
[Pages 73699-73702]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2021-27840]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2021-0959; Project Identifier AD-2021-00830-E]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney Division Turbofan
Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
[[Page 73700]]
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede Airworthiness Directive (AD)
2019-03-01 and AD 2021-05-51, which apply to certain Pratt & Whitney
Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and
PW4090-3 model turbofan engines. AD 2019-03-01 requires performing
initial and repetitive thermal acoustic image (TAI) inspections for
cracks in certain 1st-stage low-pressure compressor (LPC) blades and
removal of those blades that fail inspection. AD 2021-05-51 requires
performing a one-time TAI inspection for cracks in certain 1st-stage
LPC blades and removal of those blades that fail inspection. Since the
FAA issued AD 2019-03-01 and AD 2021-05-51, the manufacturer determined
the need to add initial and repetitive ultrasonic testing (UT)
inspections of the 1st-stage LPC blades. This proposed AD would require
initial and repetitive UT inspections and TAI inspections for cracks in
certain 1st-stage LPC blades and removal of those blades that fail
inspection. The FAA is proposing this AD to address the unsafe
condition on these products.
DATES: The FAA must receive comments on this proposed AD by January 27,
2022.
ADDRESSES: You may send comments, using the procedures found in 14 CFR
11.43 and 11.45, by any of the following methods:
<bullet> Federal eRulemaking Portal: Go to <a href="https://www.regulations.gov">https://www.regulations.gov</a>. Follow the instructions for submitting comments.
<bullet> Fax: (202) 493-2251.
<bullet> 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.
<bullet> 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 NPRM, contact Pratt &
Whitney Division, 400 Main Street, East Hartford, CT 06118; phone:
(860) 565-0140; email: <a href="/cdn-cgi/l/email-protection#eb838e879bd9dfab9b998a9f9f9c83829f858e92c5888486"><span class="__cf_email__" data-cfemail="e48c818894d6d0a49496859090938c8d908a819dca878b89">[email protected]</span></a>; website: <a href="https://connect.prattwhitney.com">https://connect.prattwhitney.com</a>. 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.
Examining the AD Docket
You may examine the AD docket at <a href="https://www.regulations.gov">https://www.regulations.gov</a> by
searching for and locating Docket No. FAA-2021-0959; 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 NPRM, 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:
<a href="/cdn-cgi/l/email-protection#66050714090a480801131f03082600070748010910"><span class="__cf_email__" data-cfemail="c2a1a3b0adaeecaca5b7bba7ac82a4a3a3eca5adb4">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under ADDRESSES. Include ``Docket No. FAA-2021-0959; Project Identifier
AD-2021-00830-E'' at the beginning of your comments. The most helpful
comments reference a specific portion of the proposal, 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
the proposal because of those comments.
The FAA has been informed that PW has done some outreach with
affected operators regarding the proposed corrective actions for this
unsafe condition. As a result, affected operators are already aware of
the proposed corrective actions and, in some cases, have already begun
implementation of the updated inspections on the 1st-stage LPC blades
proposed by this AD. Therefore, the FAA has determined that a 30-day
comment period is appropriate.
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
<a href="https://www.regulations.gov">https://www.regulations.gov</a>, including any personal information you
provide. The agency will also post a report summarizing each
substantive verbal contact we receive about this proposed AD.
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 NPRM 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 NPRM, 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 NPRM. 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.
Background
The FAA issued AD 2019-03-01, Amendment 39-19553 (84 FR 4320,
February 15, 2019) (AD 2019-03-01), and AD 2021-05-51, Amendment 39-
21470 (86 FR 13445, March 9, 2021) (AD 2021-05-51) for certain PW
PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 model
turbofan engines. AD 2019-03-01 and AD 2021-05-51 were prompted by
three in-flight failures of a 1st-stage LPC blade, with one failure
resulting in an engine fire during flight. AD 2019-03-01 and AD 2021-
05-51 require performing a TAI inspection for cracks in certain 1st-
stage LPC blades and removal of those blades that fail inspection. The
agency issued AD 2019-03-01 and AD 2021-05-51 to prevent failure of the
1st-stage LPC blades.
Actions Since AD 2019-03-01 and AD 2021-05-51 Was Issued
Since the FAA issued AD 2019-03-01 and AD 2021-05-51, the
manufacturer developed an improved UT inspection for the three critical
locations on the 1st-stage LPC blade, two at the mid span region of the
blade and one at the flow path region of the blade. The manufacturer
published Pratt & Whitney Alert Service Bulletin (ASB) PW4G-112-A72-
361, dated October 15, 2021, which provides instructions for performing
both the improved UT inspection and the TAI inspection. The
manufacturer also determined that it was necessary to adjust the
initial TAI inspection threshold and lower the repetitive TAI
inspection interval on the 1st-stage LPC blades to address the unsafe
condition.
FAA's Determination
The FAA is issuing this NPRM after determining that the unsafe
condition described previously is likely to exist or develop on other
products of the same type design.
[[Page 73701]]
Related Service Information Under 1 CFR Part 51
The FAA reviewed Pratt & Whitney ASB PW4G-112-A72-361, dated
October 15, 2021. This ASB specifies procedures for performing the TAI
and UT inspections of 1st-stage LPC blades. This service information is
reasonably available because the interested parties have access to it
through their normal course of business or by the means identified in
ADDRESSES.
Other Related Service Information
The FAA reviewed ``Engine-Driven Pump (EDP) Shutoff Valve Check''
(Subtasks 26-21-00-200-018, 26-21-00-200-019, and 26-21-00-840-022) of
Boeing 777-200/300 Aircraft Maintenance Manual, dated September 5,
2021. The service information specifies procedures for performing the
engine-driven pump shutoff valve functional check.
Proposed AD Requirements in This NPRM
This proposed AD would retain none of the requirements of AD 2019-
03-01 and AD 2021-05-51. This proposed AD would require initial and
repetitive UT inspections and TAI inspections 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.
Costs of Compliance
The FAA estimates that this AD, if adopted as proposed, would
affect 108 engines installed on airplanes of U.S. registry.
The FAA estimates the following costs to comply with this proposed
AD:
Estimated Costs
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Cost per Cost on U.S.
Action Labor cost Parts cost product operators
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Perform UT flow path inspection of 1st- 15 work-hours x $85 per $0 $1,275 $137,700
stage LPC blades. hour = $1,275.
Perform UT mid span inspection of 1st- 30 work-hours x $85 per 0 2,550 275,400
stage LPC blades. hour = $2,550.
Perform TAI inspection of 1st-stage 22 work-hours x $85 per 0 1,870 201,960
LPC blades. 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 proposed
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
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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
The FAA determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would 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 the proposed
regulation:
(1) Is not a ``significant regulatory action'' under Executive
Order 12866,
(2) Would not affect intrastate aviation in Alaska, and
(3) Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the FAA proposes to amend 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.
Sec. 39.13 [Amended]
0
2. The FAA amends Sec. 39.13 by:
0
a. Removing Airworthiness Directive (AD) 2019-03-01, Amendment 39-19553
(84 FR 4320, February 15, 2019), and AD 2021-05-51, Amendment 39-21470
(86 FR 13445, March 9, 2021); and
0
b. Adding the following new airworthiness directive:
Pratt & Whitney Division: Docket No. FAA-2021-0959; Project
Identifier AD-2021-00830-E.
[[Page 73702]]
(a) Comments Due Date
The FAA must receive comments on this airworthiness directive
(AD) action by January 27, 2022.
(b) Affected ADs
This AD replaces AD 2019-03-01, Amendment 39-19553 (84 FR 4320,
February 15, 2019), and AD 2021-05-51, Amendment 39-21470 (86 FR
13445, March 9, 2021).
(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 three in-flight failures of a 1st-stage
LPC blade, with one failure resulting in an engine fire during
flight, and subsequent manufacturer publication of service
information specifying improved inspections for three critical
locations on the 1st-stage LPC blade. 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) Initial 1st-Stage LPC Blade Inspections
(i) For 1st-stage LPC blades that have accumulated any number of
cycles since new (CSN) greater than zero, before further flight
after the effective date of this AD, perform a flow path and a mid
span ultrasonic testing (UT) inspection of the 1st-stage LPC blades
in accordance with the Accomplishment Instructions, Part A--Initial
Inspection of All LPC Fan Blades Prior to Their Return to Service,
paragraph 1.A. through C., of Pratt & Whitney Alert Service Bulletin
(ASB) PW4G-112-A72-361, dated October 15, 2021 (PW4G-112-A72-361).
Note 1 to paragraph (g)(1)(i): New fan blades that have zero CSN
do not need to undergo the initial 1st-stage LPC blade flow path and
mid span UT inspection required by paragraph (g)(1)(i) of this AD,
but must undergo the repetitive inspections of paragraph (g)(2) of
this AD.
(ii) Within the following compliance times after the effective
date of this AD, perform a thermal acoustic image (TAI) inspection
of the 1st-stage LPC blades for cracks using a method approved by
the FAA:
(A) For 1st-stage LPC blades with 1,000 CSN or more, with no
prior TAI inspection, inspect before further flight.
(B) For 1st-stage LPC blades with 1,000 flight cycles (FCs) or
more since the last TAI inspection, inspect before further flight.
(C) For 1st-stage LPC blades with fewer than 1,000 CSN, with no
prior TAI inspection, inspect before accumulating 1,000 CSN.
(D) For 1st-stage LPC blades with fewer than 1,000 FCs since the
last TAI inspection, inspect before accumulating 1,000 FCs since the
last TAI inspection.
Note 2 to paragraph (g)(1)(ii): Vendors that can perform an FAA-
approved TAI inspection are listed in the Vendor Services section of
PW4G-112-A72-361.
(2) Repetitive 1st-Stage LPC Blade Inspections
(i) Before exceeding 275 FCs since the last flow path UT
inspection, and thereafter at intervals not exceeding 275 FCs since
the last flow path UT inspection, perform a flow path UT inspection
of the 1st-stage LPC blades in accordance with the Accomplishment
Instructions, Part B--Repetitive Inspection of All LPC Fan Blades
After Their Return to Service, paragraph 1.A., of PW4G-112-A72-361.
(ii) Before exceeding 550 FCs since the last mid span UT
inspection, and thereafter at intervals not exceeding 550 FCs since
the last mid span UT inspection, perform a mid span UT inspection of
the 1st-stage LPC blades in accordance with the Accomplishment
Instructions, Part B--Repetitive Inspection of All LPC Fan Blades
After Their Return to Service, paragraphs 1.B. and C., of PW4G-112-
A72-361.
(iii) Before exceeding 1,000 FCs since the last TAI inspection,
and thereafter at intervals not exceeding 1,000 FCs since the last
TAI inspection, perform repetitive TAI inspections of the 1st-stage
LPC blades using a method approved by the FAA.
(3) Removal of the 1st-Stage LPC Blade
(i) If any 1st-stage LPC blade fails any inspection required by
paragraphs (g)(1) or (2) of this AD, before further flight, remove
the 1st-stage LPC blade from service and replace with a part
eligible for installation.
(ii) [Reserved]
(h) Special Flight Permit
Special flight permits, as described in 14 CFR 21.197 and
21.199, are not permitted except for airplanes on which the actions
specified in paragraphs (h)(1) and (2) of this AD have been done.
(1) A flow path UT inspection of the 1st-stage LPC blades for
cracking has been done as specified in the Accomplishment
Instructions, Part A--Initial Inspection of All LPC Fan Blades Prior
to their Return to Service, paragraph 1.A., of PW4G-112-A72-361, and
the 1st-stage LPC blades have been found serviceable.
(2) A functional check of the left and right hydraulic pump
shutoff valves to ensure they close in response to the fire handle
input and all applicable corrective actions (i.e., repair) within 10
days prior to flight.
Note 3 to paragraph (h)(2): Guidance for accomplishing the
actions required by paragraph (h)(2) of this AD can be found in the
``Engine-Driven Pump (EDP) Shutoff Valve Check'' (Subtasks 26-21-00-
200-018, 26-21-00-200-019, and 26-21-00-840-022) of Boeing 777-200/
300 Aircraft Maintenance Manual.
(i) Credit for Previous Actions
This paragraph provides credit for the actions specified in
paragraphs (g)(1) and (h)(1) of this AD, if those actions were
performed before the effective date of this AD using the service
information specified in paragraphs (i)(1), (2), or (3) of this AD.
(1) Paragraph 2. of the Accomplishment Instructions of Pratt &
Whitney Special Instruction No. 85F21, dated May 12, 2021, for a
flow path UT inspection.
(2) Paragraph 1.a) through c) of the Accomplishment Instructions
of Pratt & Whitney Special Instruction No. 130F-21, dated July 1,
2021, for a flow path and a mid span UT inspection.
(3) Paragraph 2.a) through c) of the Accomplishment Instructions
of Pratt & Whitney Special Instruction No. 130F-21, Revision A,
dated July 28, 2021, for a flow path and a mid span UT inspection.
(j) 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 paragraph (k)(1) of this AD. You may email your
request to: <a href="/cdn-cgi/l/email-protection#a0e1eee58de1e48de1edefe3e0c6c1c18ec7cfd6"><span class="__cf_email__" data-cfemail="d0919e95fd9194fd919d9f9390b6b1b1feb7bfa6">[email protected]</span></a>.
(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.
(k) Related Information
(1) 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: <a href="/cdn-cgi/l/email-protection#335052415c5f1d5d54464a565d735552521d545c45"><span class="__cf_email__" data-cfemail="ddbebcafb2b1f3b3baa8a4b8b39dbbbcbcf3bab2ab">[email protected]</span></a>.
(2) For service information identified in this AD, contact Pratt
& Whitney Division, 400 Main Street, East Hartford, CT 06118; phone:
(860) 565-0140; email: <a href="/cdn-cgi/l/email-protection#f8909d9488caccb8888a998c8c8f90918c969d81d69b9795"><span class="__cf_email__" data-cfemail="224a474e521016625250435656554a4b564c475b0c414d4f">[email protected]</span></a>; website: <a href="https://connect.prattwhitney.com">https://connect.prattwhitney.com</a>. You may view this referenced 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.
Issued on December 14, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification
Service.
[FR Doc. 2021-27840 Filed 12-22-21; 11:15 am]
BILLING CODE 4910-13-P
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