DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-0690; Product Identifier 2018-CE-022-AD]
RIN 2120-AA64

Airworthiness Directives; Gulfstream Aerospace Corporation
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Supplemental notice of proposed rulemaking (SNPRM); reopening
of comment period.

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SUMMARY: We are revising an earlier proposal for certain Gulfstream
Aerospace Corporation (Gulfstream) Model G-IV and Model GIV-X
airplanes. This action revises the notice of proposed rulemaking (NPRM)
by proposing to require a later revision of the service information to
update the life limits and inspection requirements in the airworthiness
limitations section (ALS) of the aircraft maintenance manual (AMM). We
are proposing this airworthiness directive (AD) to address the unsafe
condition on these products. Since these actions would impose an
additional burden over those in the NPRM, we are reopening the comment
period to allow the public the chance to comment on these changes.

DATES: The comment period for the NPRM published in the Federal
Register on August 2, 2018 (83 FR 37771), is reopened.

We must receive comments on this SNPRM by May 17, 2019.

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 http://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: U.S. Department of Transportation, Docket
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New
Jersey Avenue SE, Washington, DC 20590, between 9 a.m. and 5 p.m.,
Monday through Friday, except Federal holidays.

For service information identified in this SNPRM, contact
Gulfstream Aerospace Corporation, Technical Publications Dept., P.O.
Box 2206, Savannah, GA 31402-2206; telephone: 800-810-4853; fax: 912-
965-3520; email: pubs@gulfstream.com; Internet: http://www.gulfstream.
com/product-support/technical-publications. You may view
this service information at the FAA, Policy and Innovation Division,
901 Locust, Kansas City, Missouri 64106. For information on the
availability of this material at the FAA, call (816) 329-4148.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.
gov by searching for and locating FAA-2018-0690; 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 SNPRM, the
regulatory evaluation, any comments received, and other information.
The street address for Docket Operations (phone: 800-647-5527) is
listed above. Comments will be available in the AD docket shortly after
receipt.

FOR FURTHER INFORMATION CONTACT: Ronald "Ron" Wissing, Airframe
Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park,
Georgia 30337; phone: 404-474-5552; fax: 404-474-5606; email:
ronald.wissing@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or
arguments about this proposal. Send your comments to an address listed
under the ADDRESSES section. Include "Docket No. FAA-2018-0690;
Product Identifier 2018-CE-022-AD" at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this SNPRM. We will consider all
comments received by the closing date and may amend this SNPRM because
of those comments.

We will post all comments we receive, without change, to http://www.
regulations.gov, including any personal information you provide. We
will also post a report summarizing each substantive verbal contact we
receive about this SNPRM.

Discussion

We issued an NPRM to amend 14 CFR part 39 by adding an AD that
would apply to certain serial-numbered Gulfstream Model G-IV and Model
GIV-X airplanes. The NPRM published in the Federal Register on August
2, 2018 (83 FR 37771). The NPRM was prompted by a revision to the ALS
of the AMM based on fatigue and damage tolerance (FTD) testing and
updated analysis. The NPRM proposed to require revising the ALS in the
AMM to incorporate new inspections and life limits contained in Gulfstream
Document No. GIV-GER-0008, Summary of Changes to the GIV Series and
GIV-X Series Airworthiness Limitations, Revision B, dated March 12,
2018.

Actions Since the NPRM Was Issued

Since we issued the NPRM, Gulfstream updated the life limits in the
ALS and issued Gulfstream Document No. GIV-GER-0008, Summary of Changes
to the GIV Series and GIV-X Series Airworthiness Limitations, Revision
D, dated August 20, 2018. Revision D differs from Revision B in that
the part number (P/N) for the rudder for Model GIV airplanes has been
corrected to reflect P/N 1159CS30004, and new life limits for fuselage
cockpit side post P/N 1159BM50025-5 and P/N 1159BM50025-6 have been
added per Revision C. Since incorporating Revision D instead of
Revision B would impose an additional burden over those in the NPRM, we
are reopening the comment period to allow the public the chance to
comment on these changes.

Comments

We gave the public the opportunity to comment on the NPRM. The
following presents the comment received on the NPRM and the FAA's
response to the comment.

Request To Withdraw the NPRM

An anonymous commenter indicated that the NPRM is unnecessary. The
commenter stated the proposed requirements have already been
incorporated into the manufacturer's inspection program through a
revision to the AMM, Chapter 5. According to the commenter, the
original equipment manufacturer (OEM) publishes revisions to the AMM on
a CDROM or electronically through the OEM's website; therefore, it
would not be possible for the mechanic responsible for signing off on
the AD to physically revise Chapter 5 of the AMM as required by the
NPRM. The commenter noted the FAA's estimated cost of compliance and
stated that the NPRM does not increase safety, but rather it increases
paperwork. We infer that the commenter wanted the NPRM withdrawn.

We do not agree. In accordance with 14 CFR 39.5, the FAA issues an
AD addressing a product when we find that: (a) An unsafe condition
exists in the product; and (b) the condition is likely to exist or
develop in other products of the same type design. We will issue an AD
if a revision to the AMM ALS addresses an unsafe condition, i.e., more
restrictive inspection intervals, altered non-destructive test (NDT)
inspection requirements, and reduced life limits.

While Gulfstream operators may incorporate revisions to the AMM
into their maintenance program, not all operators are required to do
so. In order for the new life limits in Gulfstream Document No. GIV-
GER-0008, Summary of Changes to the GIV Series and GIV-X Series
Airworthiness Limitations, Revision D, dated August 20, 2018, to become
mandatory, and to correct the unsafe condition identified in the NPRM,
the FAA must require the changes by AD action.

Related Service Information Under 1 CFR Part 51

We reviewed Gulfstream Document No. GIV-GER-0008, Summary of
Changes to the GIV Series and GIV-X Series Airworthiness Limitations,
Revision D, dated August 20, 2018. The service information describes
more restrictive inspection intervals or altered NDT inspection
requirements and updated life limits that address fatigue cracking of
the principal structural elements (PSEs). Revision D of this service
information differs from previous revisions in that it corrects the P/N
for the rudder for Model GIV airplanes to reflect rudder P/N
1159CS30004 and adds new life limits for fuselage cockpit side post P/N
1159BM50025-5 and P/N 1159BM50025-6. 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
the ADDRESSES section.

FAA's Determination

We are proposing this AD because we evaluated all the relevant
information and determined the unsafe condition described previously is
likely to exist or develop in other products of the same type design.
Certain changes described above expand the scope of the NPRM. As a
result, we have determined that it is necessary to reopen the comment
period to provide additional opportunity for the public to comment on
this SNPRM.

Proposed Requirements of This SNPRM

This SNPRM would require revising the ALS of the AMM, Chapter 5
Life Limited Components and Chapter 6 PSE Inspections Intervals, to
incorporate new inspections and life limits based on FTD testing and
updated analysis.

Costs of Compliance

We estimate that this proposed AD affects 711 airplanes of U.S.
registry.

We estimate the following costs to comply with this proposed AD:

Estimated Costs

The extent of damage found during the proposed inspection may vary
from airplane to airplane. We have no way of determining the number of
airplanes that might need repairs or the cost of such repairs for each
airplane.

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.

We are 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.

This proposed AD is issued in accordance with authority delegated
by the Executive Director, Aircraft Certification Service, as authorized
by FAA Order 8000.51C. In accordance with that order, issuance of ADs is
normally a function of the Compliance and Airworthiness Division, but
during this transition period, the Executive Director has delegated the
authority to issue ADs applicable to small airplanes, gliders, balloons,
airships, domestic business jet transport airplanes, and associated
appliances to the Director of the Policy and Innovation Division.

Regulatory Findings

We 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) Is not a "significant rule" under the DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979),

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

(4) 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 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

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]

2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive (AD):