DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-0677; Directorate Identifier 2013-NM-244-AD;
Amendment 39-18289; AD 2015-20-10]
RIN 2120-AA64

Airworthiness Directives; Gulfstream Aerospace Corporation
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all
Gulfstream Aerospace Corporation Model GVI airplanes. This AD was
prompted by reports of corrosion on in-service air non-return valves.
This AD requires a revision to the Emergency Procedures section of the
airplane flight manual (AFM). This AD also requires a revision to the
maintenance or inspection program, as applicable, to incorporate
airworthiness limitations for the high pressure (HP) Stage 5 air non-
return valves. We are issuing this AD to ensure the flightcrew is
provided with procedures to mitigate the risks associated with failure of the HP
Stage 5 air non-return valve. Failure of the HP Stage 5 air non-return
valve in the open position could result in engine instability and
uncommanded in-flight shutdown.

DATES: This AD is effective November 13, 2015.
The Director of the Federal Register approved the incorporation by
reference of certain publications listed in this AD as of November 13,
2015.

ADDRESSES: For service information identified in this AD, 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_pubs/pubs/index.htm.
You may view this service information at the FAA, Transport Airplane Directorate,
1601 Lind Avenue SW., Renton, WA. For information on the availability of
this material at the FAA, call 425-227-1221. It is also available on
the Internet at http://www.regulations.gov by searching for and
locating Docket No. FAA-2015-0677.

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-2015-
0677; or in person at the Docket Management Facility between 9 a.m. and
5 p.m., Monday through Friday, except Federal holidays. The AD docket
contains this AD, the regulatory evaluation, any comments received, and
other information. The address for the Docket Office (phone: 800-647-
5527) is Docket Management Facility, 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: Darby Mirocha, Continued Operational
Safety and Certificate Management, ACE-102A, FAA, Atlanta Aircraft
Certification Office (ACO), 1701 Columbia Avenue, College Park, GA
30337; phone: 404-474-5573; fax: 404-474-5606; email:
Darby.Mirocha@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR
part 39 by adding an AD that would apply to all Gulfstream Aerospace
Corporation Model GVI airplanes. The NPRM published in the Federal
Register on March 31, 2015 (80 FR 17005). The NPRM was prompted by
reports of corrosion on in-service air non-return valves. Failure of
the HP Stage 5 air non-return valve in the open position could result
in engine instability and uncommanded in-flight shutdown. The NPRM
proposed to require a revision to the Emergency Procedures section of
the AFM and a revision to the maintenance or inspection program, as
applicable, to incorporate airworthiness limitations for the HP Stage 5
air non-return valves. We are issuing this AD to ensure the flightcrew
is provided with procedures to mitigate the risks associated with
failure of the HP Stage 5 air non-return valve.

Comments

We gave the public the opportunity to participate in developing
this AD. We received no comments on the NPRM (80 FR 17005, March 31,
2015) or on the determination of the cost to the public.

Conclusion

We reviewed the relevant data and determined that air safety and
the public interest require adopting this AD as proposed except for
minor editorial changes. We have determined that these minor changes:
Are consistent with the intent that was proposed in the
NPRM (80 FR 17005, March 31, 2015) for correcting the unsafe condition;
and
Do not add any additional burden upon the public than was
already proposed in the (NPRM 80 FR 17005, March 31, 2015).

Interim Action

We consider this AD interim action. The manufacturer is currently
developing a modification that will positively address the unsafe
condition identified in this AD. Once this modification is developed,
approved, and available, we might consider additional rulemaking.

Related Service Information Under 1 CFR Part 51

We reviewed Section 04-08-20, Normal Airstart--Automatic; Section
04-08-30, Manual Airstart--Starter Assist; and Section 04-08-40, Manual
Airstart--Windmilling; of Chapter 04, Emergency Procedures, of the
Gulfstream GVI (G650) AFM, Document Number GAC-AC-G650-OPS-0001,
Revision 5, dated August 12, 2013. This service information describes
revised procedures for in-flight engine restart and operating
procedures.
In addition, we reviewed Section 05-10-10, Airworthiness
Limitations, of Chapter 05, Time Limits/Maintenance Checks, of the
Gulfstream GVI (G650) Maintenance Manual (MM), Revision 4, dated
September 30, 2013. This service information adds an airworthiness
limitation for the HP Stage 5 air non-return valve.
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 of this
AD.

Costs of Compliance

We estimate that this AD affects 52 airplanes of U.S. registry.
We estimate the following costs to comply with this AD:

Estimated Costs

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.

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) Is not a ``significant rule'' under 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.

Adoption of 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

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):