[Federal Register Volume 87, Number 48 (Friday, March 11, 2022)]
[Rules and Regulations]
[Pages 13926-13930]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-05295]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0963; Project Identifier AD-2021-01026-T; 
Amendment 39-21977; AD 2022-06-11]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: The FAA is adopting a new airworthiness directive (AD) for 
certain The Boeing Company Model 777-200

[[Page 13927]]

and -300 series airplanes. This AD was prompted by reports of three 
incidents involving in-flight fan blade failures on certain Pratt & 
Whitney engines (``fan blades'' are also known as ``1st-stage low-
pressure compressor (LPC) blades''--these terms are used 
interchangeably in this AD). This AD requires modifying the engine 
inlet to withstand fan blade failure event loads. The FAA is issuing 
this AD to address the unsafe condition on these products.

DATES: This AD is effective April 15, 2022.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of April 15, 
2022.

ADDRESSES: For Boeing service information identified in this AD, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. For Pratt & Whitney service information 
identified in this AD contact Pratt & Whitney Division, 400 Main 
Street, East Hartford, CT 06118; phone: 860-565-0140; email: 
[email protected]; website: https://connect.prattwhitney.com. You 
may view this service information at the FAA, Airworthiness Products 
Section, Operational Safety Branch, 2200 South 216th St., Des Moines, 
WA. For information on the availability of this material at the FAA, 
call 206-231-3195. It is also available at https://www.regulations.gov 
by searching for and locating Docket No. FAA-2021-0963.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0963; 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 address for Docket 
Operations 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: Luis Cortez-Muniz, Aerospace Engineer, 
Airframe Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: (206) 231-3958; email: [email protected].

SUPPLEMENTARY INFORMATION:

Background

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to certain The Boeing 
Company Model 777-200 and -300 series airplanes. The NPRM published in 
the Federal Register on December 28, 2021 (86 FR 73688). The NPRM was 
prompted by reports of three incidents involving in-flight fan blade 
failures on certain Pratt & Whitney engines. In the NPRM, the FAA 
proposed to require modifying the engine inlet to withstand fan blade 
failure event loads. The FAA is issuing this AD to address the 
airplane-level implications of the unsafe condition of engine fan blade 
failure. Fan blade failures can cause fan rotor imbalance and result in 
fan blade fragments penetrating the inner and outer barrel of the 
inlet. This condition, if not addressed could result in engine in-
flight shutdown, and could result in separation of the inlet, the fan 
cowl doors, or the thrust reverser (T/R) cowl, or result in 
uncontrolled engine fire. Separation of the inlet, the fan cowl doors, 
or the T/R cowl could result in impact damage to the empennage and loss 
of control of the airplane, or to the fuselage or windows with 
potential injury to passengers; or it could result in significantly 
increased aerodynamic drag causing fuel exhaustion or the inability to 
maintain altitude above terrain during extended operations (ETOPS) 
flights, either of which could result in a forced off-airport landing 
and injury to passengers. Uncontrolled engine fire could result in loss 
of control of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received comments from The Air Line Pilots Association, 
International (ALPA), and two Anonymous commenters who supported the 
NPRM without change.
    The FAA received additional comments from five commenters, 
including an Anonymous commenter, All Nippon Airways (ANA), Boeing, 
Japan Airlines (JAL), and United Airlines (UAL). The following presents 
the comments received on the NPRM and the FAA's response to each 
comment.

Request To Clarify Certain Sentences in the Background Paragraph

    Boeing requested that the ``Background'' paragraph in the NPRM be 
revised to clarify that the failed hydraulic pump shutoff valve was not 
the direct cause of the uncontained engine fire. Boeing stated that 
flight data indicates that while the hydraulic pump shutoff valve 
failed to close, no hydraulic fluid was leaked from the system until 
well after the engine fire initiated.
    Boeing proposed that two sentences in the ``Background'' paragraph 
of the NPRM be revised to, ``Several flammable fluid lines, the engine 
accessory gearbox, and T/R structure were fractured and an uncontained 
engine fire occurred. The hydraulic pump shutoff valve failed to close 
when the fire handle was pulled, contributing additional flammable 
fluid to the T/R area.'' Boeing commented that the proposed wording 
recognizes that the failure may have contributed additional flammable 
fluid to the T/R area, but that it did not directly cause the 
uncontained fire.
    The FAA agrees with the commenter's clarification and did not 
intend to imply that the failed hydraulic pump shutoff valve was the 
direct cause of the uncontained engine fire. However, the detailed 
background information, which includes the sentences that the commenter 
proposed for the ``Background'' paragraph, are not carried over into 
the final rule. The FAA has not changed this final rule in this regard.

Request To Use Certain Service Information as a Method of Compliance

    ANA, an Anonymous commenter, Boeing, and UAL requested the use of 
Boeing Alert Service Bulletin 777-71A0085 and Boeing Alert Service 
Bulletin 777-71A0093, for doing the actions in paragraph (g) of the 
proposed AD. Boeing stated that the description of the modification in 
the proposed AD is vague.
    The FAA disagrees with allowing the use of Boeing Alert Service 
Bulletin 777-71A0085 and Boeing Alert Service Bulletin 777-71A0093 for 
the actions specified in paragraph (g) of this AD. The service 
bulletins are not yet FAA-approved. However, under the provisions of 
paragraph (j) of this AD, the FAA will consider requests for approval 
of the use of the service bulletins if sufficient data are submitted to 
substantiate that the service bulletins would provide an acceptable 
level of safety.

Request To Add Certain Exceptions for Ferry Flights

    JAL requested that the FAA revise the AD to include certain 
exceptions for ferry flights. JAL stated it is planning to ferry 
affected airplanes to a storage point in the United States. JAL 
commented that although the local

[[Page 13928]]

authority in Japan provides regulatory requirements for special flight 
permissions which are similar to 14 CFR 21.197, the Japanese regulatory 
requirements do not include ``to a point of storage'' language for the 
purpose of the flights. JAL proposed to add the following wording to 
paragraphs (c) and (g) of the proposed AD, ``except for ferry flights, 
without passenger and cargo, of the airplanes on which the actions 
specified in paragraphs (h)(1) and (2) of this AD have been done.''
    The FAA disagrees with revising paragraph (c) Applicability or 
paragraph (g) Modification of this AD in response to JAL's comment. 
Paragraph (i), Special Flight Permit, provides that special flight 
permits, as described in 14 CFR 21.197 and 21.199, are permitted 
provided that the actions in paragraphs (h)(1) and (2) of this AD have 
first been accomplished. 14 CFR 21.197(a)(1) provides, in relevant 
part, that a special flight permit may be issued for flying the 
aircraft to a base where repairs, alterations, or maintenance are to be 
performed, or to a point of storage. The requested change is already 
permitted by this AD. The FAA did not change this AD as a result of 
this comment.

Request To Change the Initial Compliance Time to Before Revenue Flight

    ANA requested that in paragraph (g) of the proposed AD, the FAA 
update the initial compliance time of ``before further flight after the 
effective date of this AD'' to ``before the next revenue flight'' to 
clarify the ferry flight requirement.
    Similarly, JAL requested that in paragraph (g) of the proposed AD, 
the FAA update the initial compliance time of ``before further flight 
after the effective of this AD'' to ``before the next revenue flight'' 
or ``before further flight except the ferry flight without passenger 
and cargos.''
    The FAA disagrees with revising the initial compliance time in 
paragraph (g) of this AD as requested by ANA and JAL. The FAA has 
determined it is necessary to require certain actions prior to any 
flight, except as permitted in paragraph (h), Special Flight Permit, of 
this AD.

Request To Provide a Threshold for the Special Flight Permit

    UAL requested that the FAA provide a threshold in paragraph (h)(1) 
of the proposed AD for the flow path UT inspection. UAL stated that 
omitting a compliance time in paragraph (h) of the proposed AD for the 
special flight permits creates ambiguity regarding when and how often 
the flow path UT inspection is required for special flight permits. UAL 
suggested a threshold of 275 flight cycles since the last flow path UT 
inspection.
    The FAA agrees to add a threshold of 275 cycles to paragraph (h)(1) 
of this AD, which is specified in Pratt & Whitney Alert Service 
Bulletin PW4G-112-A72-361, dated October 15, 2021. This allows 
airplanes with 1st-stage LPC blades that have accumulated 275 cycles 
since new or fewer to be eligible for a special flight permit.

Request for an Additional Method of Compliance

    UAL requested that the FAA revise paragraph (h)(1) of the proposed 
AD to add NPRM AD-2021-00830-E (86 FR 73699, December 28, 2021), as a 
method of compliance for the flow path ultrasonic testing (UT) 
inspection of the 1st-stage LPC blades.
    The FAA disagrees with the commenter's request. The method of 
compliance in Pratt & Whitney Alert Service Bulletin PW4G-112-A72-361, 
dated October 15, 2021, is the same as paragraph (i)(1) of NPRM AD-
2021-00830-E (86 FR 73699, December 28, 2021) and paragraph (h)(1) of 
this AD. If the actions in the service information are accomplished, 
the requirements in paragraph (h)(1) of this AD will have been met, and 
therefore, no change to this AD has been made.

Request To Add Aircraft Maintenance Manual Task to Special Flight 
Permit

    ANA and UAL requested that paragraph (h)(2) of the proposed AD 
include Task 29-11-00-710-806 of the Boeing 777-200/300 Aircraft 
Maintenance Manual as an acceptable method for accomplishing the 
functional check of the left and right hydraulic pump shutoff valves.
    The FAA agrees with the commenter's request and has added Task 29-
11-00-710-806 of Boeing 777-200/300 Aircraft Maintenance Manual to the 
``Other Related Service Information'' paragraph and to Note (1) to 
paragraph (h)(2) of this AD as guidance for accomplishing the actions 
required by paragraph (h)(2) of this AD.

Request To Delegate Alternative Methods of Compliance (AMOCs)

    UAL requested that if Boeing Alert Service Bulletin 777-71A0085 and 
Boeing Alert Service Bulletin 777-71A0093 become an FAA-approved method 
of compliance, the FAA should delegate The Boeing Company Organization 
Designation Authorization (ODA) authority to approve structural related 
AMOCs when deviations to the service documents are required.
    The FAA acknowledges UAL's request, however as stated previously, 
the Boeing service bulletins are not yet FAA-approved, and therefore 
ODA authority is not granted at this time. In the future, should the 
service bulletins be approved as a method of compliance to this AD, the 
FAA may consider ODA authority delegation for approval of structural-
related AMOCs for deviations to the approved method of compliance.

Additional Change Made to This AD

    In the process of preparing this final rule, the FAA noticed that 
the unsafe condition statement could be improved regarding the initial 
effects of the fan blade failure and the airplane level unsafe outcomes 
that could result from each of those initial effects. Therefore, the 
FAA has updated the unsafe condition statement in this AD to clarify 
the specific causes and hazardous effects.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Except for minor editorial changes, and any other changes 
described previously, this AD is adopted as proposed in the NPRM. None 
of the changes will increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Pratt & Whitney Alert Service Bulletin PW4G-112-
A72-361, dated October 15, 2021. This service information specifies 
procedures for performing thermal acoustic image and ultrasonic testing 
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 Subtasks 26-21-00-200-018, 26-21-00-200-019, and 
26-21-00-840-022, and Task 29-11-00-710-806, of Boeing 777-200/300 
Aircraft Maintenance Manual, dated September 5, 2021. The service 
information specifies procedures for performing a functional check of 
the engine-driven pump shutoff valve.

Interim Action

    The FAA considers this AD to be an interim action. The manufacturer 
is currently developing other actions that will address the unsafe 
condition identified in this AD. Once these actions

[[Page 13929]]

are developed, approved, and available, the FAA might consider 
additional rulemaking.

Costs of Compliance

    The FAA estimates that this AD affects 54 airplanes of U.S. 
registry. The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
                Action                         Labor cost           Parts cost        product        operators
----------------------------------------------------------------------------------------------------------------
Modification..........................  660 work-hours x $85 per        $362,560        $418,660     $22,607,640
                                         hour = $56,100.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition repairs that are part of the 
modification specified in this AD.

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,
    (2) Will not affect intrastate aviation in Alaska, and
    (3) Will 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 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.


Sec.  39.13   [Amended]

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

2022-06-11 The Boeing Company: Amendment 39-21977; Docket No. FAA-
2021-0963; Project Identifier AD-2021-01026-T.

(a) Effective Date

    This airworthiness directive (AD) is effective April 15, 2022.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to The Boeing Company airplanes, certificated in 
any category, as specified in paragraphs (c)(1) and (2) of this AD.
    (1) Model 777-200 series airplanes equipped with Pratt & Whitney 
PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 
model turbofan engines.
    (2) Model 777-300 series airplanes equipped with Pratt & Whitney 
PW4090 and PW4098 model turbofan engines.

(d) Subject

    Air Transport Association (ATA) of America Code 54, Nacelles/
pylons.

(e) Unsafe Condition

    This AD was prompted by reports of three incidents involving in-
flight fan blade failures on certain Pratt & Whitney engines. The 
FAA is issuing this AD to address engine fan blade failure, which 
could result in engine in-flight shutdown, and could result in 
separation of the inlet, the fan cowl doors, or the thrust reverser 
(T/R) cowl, or result in uncontrolled engine fire. Separation of the 
inlet, the fan cowl doors, or the T/R cowl could result in impact 
damage to the empennage and loss of control of the airplane, or to 
the fuselage or windows with potential injury to passengers; or it 
could result in significantly increased aerodynamic drag causing 
fuel exhaustion or the inability to maintain altitude above terrain 
during extended operations (ETOPS) flights, either of which could 
result in a forced off-airport landing and injury to passengers. 
Uncontrolled engine fire could result in loss of control of the 
airplane.

(f) Compliance

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

(g) Modification

    Before further flight after the effective date of this AD, 
modify the engine inlet to withstand fan blade failure event loads, 
in accordance with a method approved by the Manager, Seattle ACO 
Branch, FAA.

(h) Special Flight Permit

    Special flight permits, as described in 14 CFR 21.197 and 
21.199, are permitted provided that the actions in paragraphs (h)(1) 
and (2) of this AD have first been accomplished.
    (1) A flow path ultrasonic testing (UT) inspection of the 1st-
stage low-pressure compressor (LPC) blades for cracking has been 
done within the last 275 cycles, 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 Pratt & Whitney Alert 
Service Bulletin PW4G-112-A72-361, dated October 15, 2021, and the 
1st-stage LPC blades have been found serviceable. This inspection is 
not required for 1st-stage LPC blades with 275 cycles since new or 
fewer.
    (2) A functional check of the left and right hydraulic pump 
shutoff valves to ensure they close in response to the corresponding 
engine fire handle input and all applicable corrective actions 
(i.e., repair) within 10 days prior to flight.

    Note (1) 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, or Task 29-11-00-
710-806) of Boeing 777-200/300 Aircraft Maintenance Manual.

(i) Credit for Previous Actions

    This paragraph provides credit for the actions specified in 
paragraph (h)(1) of this AD, if those actions were performed before 
the effective date of this AD using the service information 
specified in paragraph (i)(1), (2), or (3) of this AD.

[[Page 13930]]

    (1) Paragraph 2. of the Accomplishment Instructions of Pratt & 
Whitney Special Instruction No. 85F-21, dated May 12, 2021, for a 
flow path UT inspection.
    (2) Paragraph 1.a) of the Accomplishment Instructions of Pratt & 
Whitney Special Instruction No. 130F-21, dated July 1, 2021, for a 
flow path UT inspection.
    (3) Paragraph 2.a) of the Accomplishment Instructions of Pratt & 
Whitney Special Instruction No. 130F-21, Revision A, dated July 28, 
2021, for a flow path UT inspection.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Seattle ACO 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 responsible Flight Standards 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. Information may be 
emailed to: [email protected].
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the responsible Flight Standards Office.

(k) Related Information

    (1) For more information about this AD, contact Luis Cortez-
Muniz, Aerospace Engineer, Airframe Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 
(206) 231-3958; email: [email protected].
    (2) Service information identified in this AD that is not 
incorporated by reference is available at the addresses specified in 
paragraphs (l)(3) and (4) of this AD.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Pratt & Whitney Alert Service Bulletin PW4G-112-A72-361, 
dated October 15, 2021.
    (ii) [Reserved]
    (3) For Boeing service information identified in this AD, 
contact Boeing Commercial Airplanes, Attention: Contractual & Data 
Services (C&DS), 2600 Westminster Blvd., MC 110-SK57, Seal Beach, CA 
90740-5600; telephone 562-797-1717; internet https://www.myboeingfleet.com. For Pratt & Whitney service information 
identified in this AD contact Pratt & Whitney Division, 400 Main 
Street, East Hartford, CT 06118; phone: 860-565-0140; email: 
[email protected]; website: https://connect.prattwhitney.com.
    (4) You may view this service information at the FAA, 
Airworthiness Products Section, Operational Safety Branch, 2200 
South 216th St., Des Moines, WA. For information on the availability 
of this material at the FAA, call 206-231-3195.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, [email protected], or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on March 4, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-05295 Filed 3-9-22; 4:15 pm]
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