[Federal Register Volume 87, Number 48 (Friday, March 11, 2022)]
[Rules and Regulations]
[Pages 13930-13935]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-05309]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2021-0962; Project Identifier AD-2021-00997-T; 
Amendment 39-21976; AD 2022-06-10]
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 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 
installation of debris shields on the thrust reverser (T/R) inner wall 
at the left and right sides of the lower bifurcation, inspection of the 
fan cowl doors for moisture ingression, repetitive functional checks of 
the hydraulic pump shutoff valves to ensure they close in response to 
the fire handle input, and corrective actions if necessary. 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 certain publications 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-2021-0962.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2021-0962; 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: James Laubaugh, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3622; 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 73712). 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 installation of debris shields on the T/R inner 
wall at the left and right sides of the lower bifurcation, inspection 
of the fan cowl doors for moisture ingression, repetitive functional 
checks of the hydraulic pump shutoff valves to ensure they close in 
response to the fire handle input, and corrective actions if necessary. 
The FAA is issuing this AD to address the airplane-level implications 
of the unsafe condition of engine fan blade failure. Fan blade

[[Page 13931]]

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 
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) who supported the NPRM without change.
    The FAA received additional comments from five commenters, 
including All Nippon Airways (ANA), Boeing, Japan Airlines (JAL), 
United Airlines (UAL), and an individual. 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 requested clarification on whether Boeing Alert Service 
Bulletin 777-71A0092, dated January 13, 2022, and Boeing Alert Service 
Bulletin 777-78A0103 will be allowed as an alternative method of 
compliance for the requirements in the proposed AD.
    In addition, for the actions in paragraph (g) of the proposed AD, 
Boeing and UAL requested the use of Boeing Alert Service Bulletin 777-
78A0103 for installing debris shields on the T/R inner wall at the left 
and right sides of the lower bifurcation. Boeing and UAL also proposed 
the use of Boeing Alert Service Bulletin 777-71A0092, dated January 13, 
2022, for inspecting the fan cowl doors for moisture ingression. Boeing 
stated that the description of the modification in the proposed AD is 
vague.
    The FAA agrees to allow the use of Boeing Alert Requirements 
Bulletin 777-71A0092 RB, dated January 13, 2022, for the inspection of 
the fan cowl doors for moisture ingression. The FAA has revised the 
``Related Service Information under 1 CFR part 51'' paragraph and 
paragraph (g)(2) of this AD accordingly. The FAA disagrees with 
allowing the use of Boeing Alert Service Bulletin 777-78A0103 for the 
actions specified in paragraph (g)(1) of this AD because the service 
bulletin is not yet an FAA-approved service bulletin.

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 authority in Japan provides 
regulatory requirements for special flight permissions which are 
similar to 14 CFR 21.197, Special flight permits, the Japanese 
regulatory requirements do not include ``to a point of storage'' 
language for the purpose of the flights. JAL proposes 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) Required Actions 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 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 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 Add a Note for Airplanes Under Storage or Heavy Check

    JAL requested that the FAA add a note to paragraph (g)(3) of the 
proposed AD to clarify that the repetitive functional checks are not 
applicable to airplanes under storage or heavy check.
    The FAA partially agrees with the commenter. The FAA did not intend 
for the repetitive functional checks of the left and right hydraulic 
pump shutoff valves to be performed every 10 days when the airplane is 
not flown. The FAA has revised the compliance time in paragraph (g)(3) 
of this AD to specify that the repetitive functional check is only 
required within 10 days prior to each flight. The FAA disagrees that a

[[Page 13932]]

note is necessary to specify that the functional check is not 
applicable to airplanes under storage or heavy check because of the 
previously discussed revisions to paragraph (g)(3) of this AD.

Request To Clarify the Use of Revised Non-Destructive Inspection 
Procedure (NDIP) Documents

    JAL requested clarification for the use of revised NDIP documents 
for the flow path ultrasonic (UT) inspection of the 1st-stage LPC 
blades specified in paragraph (h)(1) of the proposed AD. JAL commented 
that Pratt & Whitney Alert Service Bulletin PW4G-112-A72-361, dated 
October 15, 2021, references the UT inspection procedures in NDIP-1238, 
NDIP-1240, and NDIP-1241, which are currently at the original version. 
JAL asked if the submission of an alternative method of compliance 
(AMOC) request is necessary if the NDIPs are later revised to meet the 
requirements in paragraph (h)(1) of the proposed AD.
    The FAA acknowledges that Pratt & Whitney Alert Service Bulletin 
PW4G-112-A72-361, dated October 15, 2021, requires the latest FAA-
approved revision of NDIP-1238, NDIP-1240, and NDIP-1241 at the time 
the inspection is accomplished. Furthermore, the FAA has provided 
credit for accomplishment of the flow path UT inspection identified in 
paragraph (h)(1) of this AD using the service information specified in 
paragraph (i) of this AD.

Request To Provide a Threshold for the Special Flight Permit

    JAL and UAL requested that the FAA provide a threshold in paragraph 
(h)(1) of the proposed AD for the last flow path UT inspection. JAL 
suggested a threshold of 275 flight cycles since the last flow path UT 
inspection for 1st-stage LPC blades that have zero cycles since new and 
also for 1st-stage LPC that have accumulated any number of cycles since 
new greater than zero.
    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 To Add Aircraft Maintenance Manual Task to Special Flight 
Permit

    ANA, JAL, 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 (g)(3) of this AD as guidance for accomplishing the actions 
required by paragraphs (g)(3) and (h)(2) of this AD.

Request To Clarify Requirements in the NPRM

    ANA requested that the FAA provide clarification of why affected 
operators will have to conduct required periodic testing [repetitive 
functional checks of the left and right hydraulic pump shutoff valves] 
even though Boeing recommends similar testing to be performed as a one-
time check before return-to-service per Boeing MOM-MOM-21-0398-01B. ANA 
also requested clarification whether the repetitive 10 day interval 
continues until a terminating action has been found.
    The FAA infers that ANA considers the low average failure rate per 
flight hour of the hydraulic pump shutoff valve in service to justify 
the performance of the one-time check of the hydraulic pump shutoff 
valve described in the Boeing MOM-MOM-21-0398-01B, combined with the 
existing maintenance program recommendation to check the function of 
the hydraulic pump shutoff valve at 18,000 flight hour intervals, as 
providing an acceptable level of safety. The FAA does not agree. 
Investigation of the February 2021 incident, as specified in the 
proposed AD, revealed that the hydraulic pump shutoff valve, which is 
remotely controlled by electrical switches, does not have an indication 
to the flightcrew to indicate when the hydraulic pump shutoff valve has 
failed to move to the commanded position. The hydraulic pump shutoff 
valve failed to close when commanded via the engine fire handle in that 
incident. Failure of this hydraulic pump shutoff valve to close in 
response to commands in the event of an engine fire could lead to 
flammable fluid continuing to be supplied to an engine fire for a 
prolonged period, potentially resulting in an uncontained fire that 
jeopardizes flight safety. The FAA has determined that this issue is an 
unsafe condition requiring corrective action.
    For transport airplanes, the determination that an unsafe condition 
exists is based on several criteria, and the failure to meet one or 
more of the criteria could lead the FAA to determine that corrective 
action is warranted.
    For each identified potential safety issue on a transport airplane, 
the FAA examines the risk on the worst reasonably anticipated flights 
(flights actually predicted to occur) to ensure that each flight 
provides an acceptable level of safety (identified as ``individual 
flight risk'' in FAA risk analysis policy). That acceptable level of 
safety consists of three basic expectations:
     That each flight begins in a fail-safe state (including 
consideration of latent failure conditions and allowed dispatch states 
under the minimum equipment list (MEL)), meaning that a foreseeable 
single failure on any anticipated flight should not have a significant 
likelihood of causing a catastrophic event.
     That each flight does not have a numerical risk of a 
catastrophic event due to the issue being examined that is excessively 
(an order of magnitude or more) greater than the risk of a catastrophic 
event on an average transport airplane.
     That safety features that were prescriptively required due 
to lessons learned from past incidents and accidents are not 
excessively reduced in their effectiveness or availability.
    Failure to meet any of these three criteria can lead to a 
determination that an unsafe condition exists and AD action is 
necessary, because the level of safety on the affected flights does not 
meet the FAA's thresholds for an acceptable level of safety on 
individual flights.
    For each identified potential safety issue, the FAA also assesses 
the total cumulative risk of an event occurring at any time in the 
remaining life of the fleet of affected airplanes (identified as 
``total fleet risk'' in FAA risk analysis policy). The FAA may 
determine that corrective action is needed to limit total fleet risk 
even when the assessed individual flight risk does not violate any of 
the three individual flight risk criteria discussed above. Total fleet 
risk is typically assessed by multiplying the average probabilities of 
each of the failures or other factors that contribute to the occurrence 
of an event, the total number of airplanes affected, the average 
utilization of those airplanes, and the average remaining life for 
those airplanes. The FAA also considers the number of occupants of an 
aircraft in assessing fleet risk, and applies total

[[Page 13933]]

fleet risk guideline thresholds expressed in terms of both aircraft 
accidents and number of fatalities.
    Either excessive individual flight risk or excessive total fleet 
risk, or both, can lead the FAA to determine that an unsafe condition 
exists that requires corrective action. The FAA does not use or accept 
calculations of acceptable total fleet risk, or acceptable average per-
flight-hour risk, as a justification for taking no action on issues 
where an excessive individual flight risk is determined to exist on 
flights that are anticipated to occur.
    In this case, the FAA determined that corrective action is 
necessary under the individual flight risk guideline above to minimize 
the occurrence of flights that are not fail safe for an engine fire due 
to latent failure of the hydraulic pump shutoff valve. The repetitive 
functional check will minimize the number of flights that occur with a 
latent failure of the hydraulic pump shutoff valve. The FAA determined 
that the 10-day interval for the inspections required by paragraph (g) 
of this AD is practical and provides an acceptable level of safety.
    Additionally, regarding the commenter's request as to whether the 
repetitive 10-day interval continues until a terminating action has 
been found, the FAA has determined that the repetitive functional check 
of the left and right hydraulic pump shutoff valves is required until 
an alternative corrective action is approved.

Request for Credit for Previous Actions

    UAL requested that Boeing Alert Service Bulletin 777-71A0092, dated 
January 13, 2022, and Boeing Alert Service Bulletin 777-78A0103 be 
added to paragraph (i) of the proposed AD as credit for actions that 
were previously accomplished in paragraph (g)(1) and (2) of the 
proposed AD. UAL also requested that credit be given in paragraphs 
(i)(2) and (3) of the proposed AD for doing a mid span UT inspection, 
in addition to providing credit for doing a flow path UT inspection.
    The FAA partially agrees with the commenter's requests. The FAA has 
not yet approved a method of compliance for paragraph (g)(1) of this AD 
using a specific service bulletin, and therefore, credit cannot be 
provided. As previously mentioned the FAA has revised paragraph (g)(2) 
of this AD allowing for accomplishment of the inspection using Boeing 
Alert Requirements Bulletin 777-71A0092 RB, dated January 13, 2022 
(original revision), and therefore, credit is not necessary. Although 
Pratt & Whitney Special Instruction No. 130F-21, dated July 1, 2021, 
and Pratt & Whitney Special Instruction No. 130F-21, Revision A, dated 
July 28, 2021, include instructions for a mid span UT inspection, the 
special flight permit paragraph in this AD does not include a 
requirement for the mid span UT inspection, and therefore, credit is 
not necessary. However, the FAA has retained the credit specified in 
paragraph (i) of this AD for doing the flow path UT inspection.

Request To Delegate AMOCs

    UAL requested that if Boeing Alert Service Bulletin 777-71A0092, 
dated January 13, 2022, and Boeing Alert Service Bulletin 777-78A0103 
become a 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 partially agrees with the commenter. For Boeing service 
bulletins that are not yet FAA-approved, the ODA authority is not 
granted at this time. However, for Boeing service bulletins that are 
FAA-approved, the FAA has added a provision in paragraph (j)(3) of this 
AD for delegation to The Boeing Company ODA for approval of certain 
AMOCs. This provision allows Boeing to propose to the FAA the types of 
AMOCs that may be approved by The Boeing Company ODA.

Request for an Additional Person To Conduct the Inspection

    An individual commenter stated that there are only 54 airplanes 
flying in the United States that need inspections and believes that 
someone who is involved in the professional side of the NPRM should be 
required to be present while the airplane is being inspected to ensure 
it is being done correctly. The commenter believes this will allow the 
airplane to be inspected the same across the board rather than each 
operator inspecting it differently. The commenter also believes that 
the NPRM has been needed since the first account of the fan blade 
failure.
    The FAA infers that the commenter is suggesting additional FAA 
oversight is necessary for the fan cowl door moisture ingression 
inspections required by this AD. The FAA has reviewed the service 
information for the fan cowl door moisture ingression inspections and 
has determined that the FAA's existing oversight activity for operators 
performing such inspections provide an acceptable level of safety. The 
FAA has not changed this final rule in this regard.

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 has reviewed Boeing Alert Requirements Bulletin 777-71A0092 
RB, dated January 13, 2022. This service information specifies 
procedures for inspecting the fan cowl doors for moisture ingression. 
The FAA also 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 also 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 are developed, 
approved, and available, the FAA might consider additional rulemaking.

[[Page 13934]]

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 on U.S.
              Action                    Labor cost        Parts cost      Cost per product        operators
----------------------------------------------------------------------------------------------------------------
Installation of T/R debris         115 work-hour x $85          $4,300  $14,075............  $760,050.
 shields.                           per hour = $9,775.
Inspection of fan cowl doors.....  64 work-hours x $85               0  $5,440.............  $293,760.
                                    per hour = $5,440.
Functional checks of the           1 work-hour x $85                 0  $85 per inspection   $4,590 per
 hydraulic pump shutoff valves.     per hour = $85 per                   cycle.               inspection cycle.
                                    inspection cycle.
----------------------------------------------------------------------------------------------------------------

    The FAA has received no definitive data on which to base the cost 
estimates for the on-condition corrective actions (i.e. repair) 
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:

2022-06-10 The Boeing Company: Amendment 39-21976; Docket No. FAA-
2021-0962; Project Identifier AD-2021-00997-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 71, Powerplant.

(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) Installation and Inspections

    Before further flight after the effective date of this AD, do 
the actions specified in paragraphs (g)(1) through (3) of this AD. 
Repeat the functional check specified in paragraph (g)(3) of this AD 
within 10 days prior to each flight.
    (1) Install debris shields on the T/R inner wall at the left and 
right sides of the lower bifurcation, in accordance with a method 
approved by the Manager, Seattle ACO Branch, FAA.
    (2) Inspect the fan cowl doors for moisture ingression in 
accordance with paragraphs (g)(2)(i) or (ii) of this AD, as 
applicable.
    (i) Do the inspection in accordance with a method approved by 
the Manager, Seattle ACO Branch, FAA. If any moisture ingression is 
found, repair before further flight, in accordance with a method 
approved by the Manager, Seattle ACO Branch, FAA.
    (ii) Do all applicable actions identified in, and in accordance 
with, the Accomplishment Instructions of Boeing Alert Requirements 
Bulletin 777-71A0092 RB, dated January 13, 2022, except where Boeing 
Alert Requirements Bulletin 777-71A0092 RB, dated January 13, 2022, 
specifies to report inspection findings, this AD does not require 
any report, and where Boeing Alert Requirements Bulletin 777-71A0092 
RB, dated January 13, 2022, specifies to contact

[[Page 13935]]

Boeing for a repair, this AD requires the repair to be accomplished 
in accordance with a method approved by the Manager, Seattle ACO 
Branch, FAA.
    (3) Do 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. If any hydraulic pump shutoff valve does 
not close, before further flight perform corrective actions until it 
closes in response to the corresponding engine fire handle input.

    Note (1) to paragraph (g)(3):  Guidance for accomplishing the 
actions required by paragraphs (g)(3) and (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.

(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.

(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.
    (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.
    (3) An AMOC that provides an acceptable level of safety may be 
used for any repair, modification, or alteration required by this AD 
if it is approved by The Boeing Company Organization Designation 
Authorization (ODA) that has been authorized by the Manager, Seattle 
ACO Branch, FAA, to make those findings. To be approved, the repair 
method, modification deviation, or alteration deviation must meet 
the certification basis of the airplane, and the approval must 
specifically refer to this AD.

(k) Related Information

    (1) For more information about this AD, contact James Laubaugh, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3622; 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) Boeing Alert Requirements Bulletin 777-71A0092 RB, dated 
January 13, 2022.
    (ii) Pratt & Whitney Alert Service Bulletin PW4G-112-A72-361, 
dated October 15, 2021.
    (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. 2022-05309 Filed 3-9-22; 4:15 pm]
BILLING CODE 4910-13-P


