DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0713; Product Identifier 2019-CE-061-AD]
RIN 2120-AA64

Airworthiness Directives; Gulfstream Aerospace Corporation
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Proposed rule; withdrawal.

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SUMMARY: The FAA is withdrawing a notice of proposed rulemaking (NPRM)
that proposed to adopt a new airworthiness directive (AD) for certain
Gulfstream Aerospace Corporation (Gulfstream) Model GVII-G500
airplanes. The NPRM was prompted by a report of a fuel quantity
disparity between the overhead panel touch screens and the touch screen
controllers. The NPRM proposed to require incorporating operating
limitations into the airplane flight manual (AFM) until the fuel
quantity management system (FQMS) software is updated. Since issuance
of the NPRM, the FAA has determined that there is not an unsafe
condition because all affected airplanes have updated software.
Accordingly, the NPRM is withdrawn.

DATES: As of July 23, 2021, the proposed rule, which published in the
Federal Register on July 28, 2020 (85 FR 45345), is withdrawn.

ADDRESSES:

Examining the AD Docket

You may examine the AD docket at https://www.regulations.gov by
searching for and locating Docket No. FAA-2020-0713; 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 AD action, any
comments received, and other information. The street 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: Jared Meyer, Aviation Safety Engineer,
Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park, GA 30337;
phone: (404) 474-5534; fax: (404) 474-5605; email: jared.meyer@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

The FAA issued an NPRM that proposed to amend 14 CFR part 39 by
adding an AD that would apply to certain serial-numbered Gulfstream
Model GVII-G500 airplanes. The NPRM published in the Federal Register
on July 28, 2020 (85 FR 45345). The NPRM was prompted by a report of
the affected airplanes exhibiting a disparity between the fuel
quantities displayed on the overhead panel touch screens and the fuel
quantities displayed on the touch screen controllers. An investigation
revealed two known failure conditions that the Model GVII-G500 FQMS
does not properly detect and report to the crew. These failure
conditions are fuel quantity probe drift and an FQMS over-current
condition, which could result in erroneous and misleading fuel quantity
indications and could also result in erroneous and misleading fuel
imbalance indications. These conditions could cause a false
annunciation of a fuel imbalance, a failure to annunciate an actual
fuel imbalance, and a condition where the actual fuel quantity is less
than or greater than the indicated fuel quantity. The FQMS software
logic does not properly detect or compensate for these failure
conditions. This condition, if not corrected, could result in fuel
starvation during flight, performance impacts of the airplane having
more fuel than indicated, and a roll moment due to a fuel imbalance.

The NPRM proposed to require incorporating operating limitations
into the AFM until the fuel quantity signal conditioner FQMS software
is updated to version 10003-42130-01-19.03.

Actions Since the NPRM Was Issued

After issuance of the NPRM, the FAA determined that all Gulfstream
Model GVII-G500 airplanes are in compliance with the proposed software
update, and the unsafe condition has been removed from the fleet. In
addition, since Gulfstream controls the software, it is unlikely the
unsafe condition will be re-introduced.

Based on the above information, the FAA has determined that AD
action is not warranted and the proposal should be withdrawn.

Comments

The FAA received comments from Gulfstream and an individual
commenter.

Requests

Gulfstream requested that the FAA change the credit for previous
actions. The individual commenter requested the FAA clarify the correct
revision of the service information to reference.
The FAA acknowledges these comments. However, because the NPRM is
being withdrawn, the commenters' requests are no longer necessary.
Withdrawal of the NPRM constitutes only such action and does not
preclude the FAA from further rulemaking on this issue, nor does it
commit the FAA to any course of action in the future.

Regulatory Findings

Since this action only withdraws an NPRM, it is neither a proposed
AD nor a final rule. This action, therefore, is not covered under
Executive Order 12866 or the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.

The Withdrawal

Accordingly, the notice of proposed rulemaking, which published in the
Federal Register on July 28, 2020 (85 FR 45345), is withdrawn.

Issued on July 15, 2021.
Ross Landes,
Deputy Director for Regulatory Operations, Compliance & Airworthiness
Division, Aircraft Certification Service.