[Federal Register Volume 87, Number 54 (Monday, March 21, 2022)]
[Proposed Rules]
[Pages 15902-15905]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-05602]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2022-0103; Project Identifier AD-2021-00977-T]
RIN 2120-AA64


Airworthiness Directives; The Boeing Company Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain The Boeing Company Model 777 airplanes. This proposed AD 
was prompted by reports of discrepancies between the center wing tank 
(CWT) fuel quantity, as indicated by the fuel quantity indicating 
system (FQIS), and the refueling truck uploaded fuel amount, followed 
by certain engine-indicating and crew-alerting system (EICAS) messages. 
This proposed AD would require installing new software in the fuel 
quantity processor unit (FQPU), or replacing the FQPU with one that 
includes new software, depending on airplane configuration; and doing a 
software version check and FQPU operational check. This proposed AD 
would also prohibit the installation of certain FQPUs on certain 
airplanes. 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 May 5, 
2022.

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 NPRM, 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. You may 
view this referenced 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-2022-
0103.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2022-0103; 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: Kevin Nguyen, Aerospace Engineer, 
Propulsion Section, FAA, Seattle ACO Branch, 2200 South 216th St., Des 
Moines, WA 98198; phone and fax: 206-231-3555; email: 
[email protected].

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-2022-0103; Project Identifier 
AD-2021-00977-T'' 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 
this proposal 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

[[Page 15903]]

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 NPRM.

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 Kevin 
Nguyen, Aerospace Engineer, Propulsion Section, FAA, Seattle ACO 
Branch, 2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-
231-3555; email: [email protected]. 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 has received reports of discrepancies between the airplane 
FQIS, specifically the CWT fuel quantity and the refueling truck 
uploaded fuel amount, followed by an engine-indicating and crew-
alerting system (EICAS) FUEL DISAGREE message at an early stage of 
flight (for example, within 3 hours after takeoff), and/or an EICAS 
INSUFFICIENT FUEL message. At least 25 in-service events have been 
reported by operators. In at least 17 of these events, the airplanes 
continued with the mission; of those, six landed at the destination 
airport, and 11 had to land at a diversion airport.
    As a result of those reports, the FAA issued AD 2020-11-11, 
Amendment 39-19915 (85 FR 34090, June 3, 2020) (AD 2020-11-11) for 
certain The Boeing Company Model 777 airplanes. AD 2020-11-11 requires 
a repetitive check of the FQIS fuel quantity calculation for the CWT, 
developing a process to provide documentation to the flight crew that 
this check was done, and revising the existing airplane flight manual 
(AFM) to incorporate verification procedures and flight crew awareness. 
The preamble to AD 2020-11-11 explains that the FAA considered the 
requirements ``interim action'' and was considering further rulemaking. 
The FAA has now determined that further rulemaking is indeed necessary, 
and this proposed AD follows from that determination.
    Insufficient fuel in the CWT as a result of this discrepancy is due 
to a design flaw in the FQIS in which the FQIS ultrasonic tank units 
calibrate incorrect velocity of sound (VOS) in the jet fuel during 
center tank fueling, which leads to an improper fuel density 
calculation, and results in the FQIS showing a different fuel amount 
from the actual fuel quantity in the CWT. Current FQPU gauging software 
is subjected to this stale VOS value under certain conditions due to 
insufficient VOS reset functions.
    In almost all of the events, the FQIS showed more fuel than the 
actual fuel quantity in the CWT, resulting in less fuel on the airplane 
than the required fuel load for the mission. Alternatively, the FQIS 
could show less fuel than the actual fuel quantity in the CWT, 
resulting in more fuel on the airplane than the required fuel load for 
the mission. This issue affects only the CWT and not the main tanks. 
This incorrect fuel quantity information is also provided to the flight 
deck Fuel Quantity Display and the flight management function (FMF) of 
the Airplane Information Management System (AIMS).
    The existing airplane maintenance manual and operator fueling 
procedures require verification that the correct fuel amount required 
for the current mission has been loaded onto the airplane. The FAA has 
received reports that verification tasks are either not accomplished or 
done incorrectly. As a result, the flight crew may be unaware of 
insufficient fuel loaded in the CWT and the airplane is dispatched for 
the mission. The airplane onboard fuel management system typically 
reports fuel quantity anomalies within the first three hours of flight 
resulting in a FUEL DISAGREE EICAS message and/or an INSUFFICIENT FUEL 
EICAS message that necessitates fuel check (e.g., leak check) and fuel 
quantity monitoring. These messages may require the flight crew to take 
action, such as performing an air turn back or a diversion.
    This AD was prompted by reports of discrepancies between the CWT 
fuel quantity, as indicated by the FQIS, and the actual amount uploaded 
from the refueling truck. The FAA is issuing this AD to address 
discrepancies in the CWT FQIS, which can result in an airplane being 
dispatched with insufficient fuel in the CWT and with the flight crew 
unaware of the insufficient fuel prior to departure. This condition, 
coupled with continued flight to the destination airport after 
receiving EICAS messages while en route to the destination, could 
result in fuel exhaustion and subsequent power loss to all engines, 
thereby resulting in the inability to land at the destination airport 
or at a diversion airport, possibly leading to flight into terrain.

Other Relevant Rulemaking

    AD 2020-11-11 addresses the same unsafe condition addressed by this 
proposed AD. While an operator is incorporating the requirements in 
this proposed AD on their fleet, they will have a mixed fleet with 
different requirements, depending on whether or not the actions in this 
proposed AD have been accomplished on a given airplane. This could make 
it challenging for fuel vendors or other personnel to determine whether 
a particular airplane needed to undergo the procedures required by AD 
2020-11-11 when fueling that airplane. The FAA has therefore determined 
that the actions required by this proposed AD must be accomplished on 
all affected airplanes in an operator's fleet before the requirements 
of AD 2020-11-11 are terminated for that fleet. However, once the 
actions required by this proposed AD are accomplished on all affected 
airplanes in an operator's fleet, the requirements of AD 2020-11-11 are 
terminated for that fleet.

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.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Boeing Alert Requirements Bulletin 777-28A0090 RB, 
dated March 30, 2021. This service information specifies procedures for 
a check of maintenance or delivery records or an inspection to 
determine the part number of the FQPU for Group 1 airplanes. For Group 
1 airplanes with a FQIS-1 FQPU, this service information specifies 
procedures for removing the existing FQPU and installing certain FQIS-2 
FQPU with upgraded software, and doing a software version check and 
FQPU operational check. For Group 1 airplanes with a FQIS-2 FQPU and 
Group 2 airplanes, this service information specifies procedures for 
upgrading the FQPU

[[Page 15904]]

software and doing a software version check.
    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.

Proposed AD Requirements in This NPRM

    This proposed AD would require accomplishing the actions specified 
in the service information already described. For information on the 
procedures and compliance times, see this service information at 
https://www.regulations.gov by searching for and locating Docket No. 
FAA-2022-0103.

Costs of Compliance

    The FAA estimates that this AD, if adopted as proposed, would 
affect 257 airplanes of U.S. registry. The FAA estimates the following 
costs to comply with this proposed AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                         Parts       Cost per      Cost on U.S.
                 Action                            Labor cost             cost        product        operators
----------------------------------------------------------------------------------------------------------------
Records review or inspection of FQPU      1 work-hour x $85 per hour          $0             $85         $12,155
 part number for Group 1 airplanes (143    = $85.
 airplanes).
Group 1 with FQIS-1 FQPU (125             1 work-hour x $85 per hour      48,300          48,385       6,048,125
 airplanes): Replace FQPU with FQIS-2      = $85.
 FQPU, and do software and FQPU checks.
Group 1 with FQIS-2 FQPU and Group 2      1 work-hour x $85 per hour           0              85          11,220
 (132 airplanes): Upgrade software and     = $85.
 do software check.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the software manufacturer, however, some or all of the 
costs of this proposed AD may be covered under warranty, thereby 
reducing the cost impact on affected operators.

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 this 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 adding the following new airworthiness 
directive:

The Boeing Company: Docket No. FAA-2022-0103; Project Identifier AD-
2021-00977-T.

(a) Comments Due Date

    The FAA must receive comments on this airworthiness directive 
(AD) by May 5, 2022.

(b) Affected ADs

    This AD affects AD 2020-11-11, Amendment 39-19915 (85 FR 34090, 
June 3, 2020) (AD 2020-11-11).

(c) Applicability

    This AD applies to The Boeing Company Model 777-200, -200LR, -
300, -300ER, and 777F series airplanes, certificated in any 
category, Group 1 and Group 2 as identified in Boeing Alert 
Requirements Bulletin 777-28A0090 RB, dated March 30, 2021.

(d) Subject

    Air Transport Association (ATA) of America Code 28, Fuel.

(e) Unsafe Condition

    This AD was prompted by reports of discrepancies between the 
center wing tank (CWT) fuel quantity, as indicated by the fuel 
quantity indicating system (FQIS), and the actual amount uploaded 
from the refueling truck. The FAA is issuing this AD to address 
discrepancies in the CWT FQIS, which can result in an airplane being 
dispatched with insufficient fuel in the CWT and with the flight 
crew unaware of the insufficient fuel prior to departure. This 
condition, coupled with continued flight to the destination airport 
after receiving engine-indicating and crew-alerting system (EICAS) 
messages while in route to the destination, could result in fuel 
exhaustion and subsequent power loss to all engines, thereby 
resulting in the inability to land at the destination airport or at 
a diversion airport, possibly leading to flight into terrain.

(f) Compliance

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

(g) Required Actions

    Except as specified by paragraph (h) of this AD: At the 
applicable times specified in the ``Compliance'' paragraph of Boeing 
Alert Requirements Bulletin 777-28A0090 RB, dated March 30, 2021, do 
all applicable actions identified in, and in accordance with, the 
Accomplishment Instructions of Boeing Alert Requirements Bulletin 
777-28A0090 RB, dated March 30, 2021.
    Note 1 to paragraph (g): Guidance for accomplishing the actions 
required by this AD can be found in Boeing Alert Service Bulletin 
777-28A0090, dated March 30, 2021, which is referred to in Boeing 
Alert Requirements Bulletin 777-28A0090 RB, dated March 30, 2021.

(h) Exceptions to Service Information Specifications

    Where the Compliance Time column of the tables in the 
``Compliance'' paragraph of

[[Page 15905]]

Boeing Alert Requirements Bulletin 777-28A0090 RB, dated March 30, 
2021, uses the phrase ``the original issue date of Requirements 
Bulletin 777-28A0090 RB,'' this AD requires using ``the effective 
date of this AD.''

(i) Terminating Action for AD 2020-11-11

    Accomplishing the actions required by this AD on all affected 
airplanes in an operator's fleet terminates the requirements of AD 
2020-11-11 for that fleet.

(j) Parts Installation Prohibition

    As of the effective date of this AD, no person may install a 
fuel quantity processor unit (FQPU), part number (P/N) 0320KPU01 
(Boeing P/N S345W001-010), on any airplane identified as Group 1 in 
Boeing Alert Requirements Bulletin 777-28A0090 RB, dated March 30, 
2021.

(k) 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 (l)(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.

(l) Related Information

    (1) For more information about this AD, contact Kevin Nguyen, 
Aerospace Engineer, Propulsion Section, FAA, Seattle ACO Branch, 
2200 South 216th St., Des Moines, WA 98198; phone and fax: 206-231-
3555; email: [email protected].
    (2) For 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. You may view this referenced 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.

    Issued on February 11, 2022.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2022-05602 Filed 3-18-22; 8:45 am]
BILLING CODE 4910-13-P


