DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2018-1006; Product Identifier 2018-NM-142-AD]
RIN 2120-AA64

Airworthiness Directives; Gulfstream Aerospace LP (Type
Certificate Previously Held by Israel Aircraft Industries, Ltd.)
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for
certain Gulfstream Aerospace LP Model Gulfstream G150 airplanes. This
proposed AD was prompted by reports of corrosion in the solder joints
of the upper and lower front relay box connectors to the printed
circuit board. This proposed AD would require replacement of the
existing relay boxes with modified boxes. We are proposing this AD to
address the unsafe condition on these products.

DATES: We must receive comments on this proposed AD by January 25, 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: 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 Gulfstream
Aerospace Corporation, P.O. Box 2206, Mail Station D-25, Savannah, GA
31402-2206; telephone 800-810-4853; fax 912-965-3520; email
pubs@gulfstream.com; internet http://www.gulfstream.com/product_support/
technical_pubs/pubs/index.htm. You may view this service information at
the FAA, Transport Standards Branch, 2200 South 216th St., Des Moines, WA.
For information on the availability of this material at the FAA, call 206-
231-3195.

Examining the AD Docket

You may examine the AD docket on the internet at http://www.regulations.
gov by searching for and locating Docket No. FAA-2018-1006;
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, the regulatory evaluation, any comments received, and other
information. The street address for Docket Operations (phone: 800-647-
5527) is in the ADDRESSES section. Comments will be available in the AD
docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT: Tom Rodriguez, Aerospace Engineer,
International Section, Transport Standards Branch, FAA, 2200 South
216th St., Des Moines, WA 98198; telephone and fax 206-231-3226.

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-2018-1006;
Product Identifier 2018-NM-142-AD" at the beginning of your comments.
We specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of this NPRM. We will consider all
comments received by the closing date and may amend this NPRM 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 NPRM.

Discussion

The Civil Aviation Authority of Israel (CAAI), which is the
aviation authority for Israel, has issued Israeli Airworthiness
Directive ISR-I-24-2018-09-7, dated October 1, 2018 (referred to after
this as the Mandatory Continuing Airworthiness Information, or "the
MCAI"), to correct an unsafe condition for certain Gulfstream
Aerospace LP Model Gulfstream G150 airplanes. The MCAI states:

The existing Upper and Lower Front Relay Box might be prone to
corrosion in the relay box connector's solder joint to the printed
circuit board. As a result various CAS [crew alerting system]
messages such as slats unbalance and auto slats fail, Mach trim
fail, etc. . . . might be reported [and could interfere with
continued safe operation of the airplane]. To prevent this condition
replacement of existing relay boxes with modified boxes featuring an
added acrylic conformal coating should be performed.

Five occurrences on G150 model in last 3 years had been reported.

You may examine the MCAI in the AD docket on the internet at http://www.
regulations.gov by searching for and locating Docket No. FAA-2018-1006.

Related Service Information Under 1 CFR Part 51

Gulfstream has issued Service Bulletin 150-24-193, dated March 30,
2018. This service information describes procedures for removing and
replacing the upper and lower front relay boxes.

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

This product has been approved by the aviation authority of another
country, and is approved for operation in the United States. Pursuant
to our bilateral agreement with the State of Design Authority, we have
been notified of the unsafe condition described in the MCAI and service
information referenced above. 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 on other
products of the same type design.

Proposed Requirements of This NPRM

This proposed AD would require accomplishing the actions specified
in the service information described previously.

Costs of Compliance

We estimate that this proposed AD affects 81 airplanes of U.S.
registry. We estimate the following costs to comply with this proposed
AD:

Estimated Costs for Required Actions

According to the manufacturer, some or all of the costs of this
proposed AD may be covered under warranty, thereby reducing the cost
impact on affected individuals. We do not control warranty coverage for
affected individuals. As a result, we have included all known costs in
our cost estimate.

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 transport category airplanes to the Director of the System Oversight
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):