AD 2020-12-06

final rule

Airworthiness Directives; Gulfstream Aerospace Corporation Airplanes

AD Number
2020-12-06
Status
final_rule
Effective Date
Product Category
aircraft
Docket
Docket No. FAA-2019-1060
FR Citation
85 FR 36143

Applicability

TypeManufacturerModelDetails
aircraft Gulfstream Various Airworthiness Directives; Gulfstream Aerospace Corporation Airplanes

Unsafe Condition

The supplier compromised the seals during assembly of the electro-hydraulic servo valves, which allows moisture to enter the valve. During cold soak conditions, the moisture forms ice crystals in the servo valve armature air gaps, which may cause the valve armature to displace to a non-neutral position.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Replacing the nose wheel steering servo valve manifold, incorporating revised operating procedures into the airplane flight manual (AFM), doing a records inspection for any incidents of un-commanded nose wheel steering turns, and reporting the results to the FAA.

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Compliance Time

Before further flight

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Affected Aircraft

All Gulfstream Model G-IV airplanes.

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Federal Register Abstract

The FAA is adopting a new airworthiness directive (AD) for all Gulfstream Aerospace Corporation (Gulfstream) Model G-IV airplanes. This AD was prompted by reports of un-commanded nose wheel steering turns. This AD requires replacing the nose wheel steering servo valve manifold, incorporating revised operating procedures into the airplane flight manual (AFM), doing a records inspection for any incidents of un-commanded nose wheel steering turns, and reporting the results to the FAA. The FAA is issuing this AD to address the unsafe condition on these products.

Applicability Source Text

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(c) Applicability

    This AD applies to Gulfstream Aerospace Corporation Model G-IV 
airplanes, certificated in any category.

Document Text

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[Federal Register Volume 85, Number 115 (Monday, June 15, 2020)]
[Rules and Regulations]
[Pages 36143-36145]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2020-12812]



========================================================================
Rules and Regulations
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains regulatory documents 
having general applicability and legal effect, most of which are keyed 
to and codified in the Code of Federal Regulations, which is published 
under 50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by the Superintendent of Documents. 

========================================================================


Federal Register / Vol. 85, No. 115 / Monday, June 15, 2020 / Rules 
and Regulations

[[Page 36143]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2019-1060; Product Identifier 2018-CE-020-AD; Amendment 
39-21141; AD 2020-12-06]
RIN 2120-AA64


Airworthiness Directives; Gulfstream Aerospace Corporation 
Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is adopting a new airworthiness directive (AD) for all 
Gulfstream Aerospace Corporation (Gulfstream) Model G-IV airplanes. 
This AD was prompted by reports of un-commanded nose wheel steering 
turns. This AD requires replacing the nose wheel steering servo valve 
manifold, incorporating revised operating procedures into the airplane 
flight manual (AFM), doing a records inspection for any incidents of 
un-commanded nose wheel steering turns, and reporting the results to 
the FAA. The FAA is issuing this AD to address the unsafe condition on 
these products.

DATES: This AD is effective July 20, 2020.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in this AD as of July 20, 
2020.

ADDRESSES: For service information identified in this final rule, 
contact Gulfstream Aerospace Corporation, Technical Publications Dept., 
P.O. Box 2206, Savannah, Georgia 31402-2206; telephone: (800) 810-4853; 
fax 912-965-3520; email: <a href="/cdn-cgi/l/email-protection#4d3d382f3e0d2a38212b3e393f282c20632e2220"><span class="__cf_email__" data-cfemail="87f7f2e5f4c7e0f2ebe1f4f3f5e2e6eaa9e4e8ea">[email&#160;protected]</span></a>; internet: <a href="https://www.gulfstream.com/customer-support">https://www.gulfstream.com/customer-support</a>. You may view this service 
information at the FAA, Airworthiness Products Section, Operational 
Safety Branch, 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 <a href="https://www.regulations.gov">https://www.regulations.gov</a> by searching for and locating Docket No. FAA-2019-
1060; 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 final rule, the regulatory evaluation, any comments received, and 
other information. The address for Docket Operations is Docket 
Operations, 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: Alex Armas, Aerospace Engineer, 
Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park, Georgia 
30337; phone: (404) 474-5538; fax: (404) 474-5605; email: 
<a href="/cdn-cgi/l/email-protection#bbdad7dec395dac9d6dac8fbdddada95dcd4cd"><span class="__cf_email__" data-cfemail="5a3b363f22743b28373b291a3c3b3b743d352c">[email&#160;protected]</span></a>.

SUPPLEMENTARY INFORMATION: 

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 by adding an AD that would apply to all Gulfstream Model G-
IV airplanes. The NPRM was published in the Federal Register on 
December 27, 2019 (84 FR 71333). The NPRM was prompted by reports of 
un-commanded nose wheel steering turns. An investigation revealed the 
supplier compromised the seals during assembly of the electro-hydraulic 
servo valves, which allows moisture to enter the valve. During cold 
soak conditions, the moisture forms ice crystals in the servo valve 
armature air gaps, which may cause the valve armature to displace to a 
non-neutral position. This condition, if not addressed, could result in 
an un-commanded nose wheel position once power is applied to the nose 
wheel servo and subsequent lateral runway departure. To address this 
condition, the supplier improved their production quality control 
process to reduce the risk of compromised seals in the nose wheel 
steering servo valve. Gulfstream also revised the normal, abnormal, and 
emergency procedures in the AFMs related to nose wheel steering un-
commanded turns.
    Accordingly, this AD requires replacing the nose wheel steering 
servo valve manifold, incorporating revised operating procedures into 
the AFM, doing a records inspection for any incidents of un-commanded 
nose wheel steering turns, and reporting the results to the FAA. The 
FAA is issuing this AD to address the unsafe condition on these 
products.

Comments

    The FAA gave the public the opportunity to participate in 
developing this final rule. The following presents the comment received 
on the NPRM and the FAA's response to the comment.

Request To Add Crew Training Verbiage

    Gulfstream requested the FAA add verbiage to the preamble 
referencing training that Gulfstream developed for the un-commanded 
nose wheel steering issue. Gulfstream stated the flight crew training 
is an important mitigation component should an aircraft experience an 
un-commanded nose wheel steering turn during landing.
    The FAA disagrees. The reduction in risk associated with 
incorporation of the flight crew training verbiage is minimal. The 
sudden and unpredicted nature of an un-commanded nose wheel steering 
event allows for little to no response from the flight crew, even with 
the related training. The primary means of mitigation for an un-
commanded nose wheel steering event is replacement of the nose wheel 
steering valve manifold assembly, which will prevent un-commanded turns 
from occurring. The FAA did not change this AD based on this comment.

Conclusion

    The FAA reviewed the relevant data, considered the comment 
received, and determined that air safety and the public interest 
require adopting this final rule as proposed.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Gulfstream IV Customer Bulletin Number 244, dated 
March 12, 2018; Gulfstream G300 Customer Bulletin 244, dated March 12, 
2018; and Gulfstream G400 Customer Bulletin 244, dated March 12, 2018. 
For the applicable airplane configuration, each customer bulletin 
describes

[[Page 36144]]

procedures for replacing the nose wheel steering servo valve manifold 
assembly.
    The FAA also reviewed Gulfstream IV Airplane Flight Manual, 
Gulfstream Aerospace Document Number GAC-AC-GIV-OPS-0001, Revision 52, 
dated October 30, 2017; Gulfstream G300 Airplane Flight Manual, 
Gulfstream Aerospace Document Number GAC-AC-G300-OPS-0001, Revision 20, 
dated October 30, 2017; and Gulfstream G400 Airplane Flight Manual, 
Gulfstream Aerospace Document Number GAC-AC-G400-OPS-0001, Revision 20, 
dated October 30, 2017. For the applicable airplane configuration, each 
AFM document provides revisions to the AFM with instructions for flight 
crew to follow if un-commanded nose wheel steering turns occur.
    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.

Costs of Compliance

    The FAA estimates that this AD will affect 425 airplanes of U.S. 
registry.
    The FAA estimates the following costs to comply with this AD:

                                                 Estimated Costs
----------------------------------------------------------------------------------------------------------------
                                                                                     Cost per      Cost on U.S.
              Action                      Labor cost             Parts cost           product        operators
----------------------------------------------------------------------------------------------------------------
Incorporate AFM revisions.........  1 work-hour x $85 per  Not applicable.......             $85         $36,125
                                     hour = $85.
Replace nose wheel steering servo   7 work-hours x $85     $63,624..............          64,219      27,293,075
 valve.                              per hour = $595.
Records review and reporting of     2 work-hours x $85     Not applicable.......             170          72,250
 the review results.                 per hour = $170.
----------------------------------------------------------------------------------------------------------------

    According to the manufacturer, some of the costs of this AD may be 
covered under warranty, thereby reducing the cost impact on affected 
individuals. The FAA does not control warranty coverage for affected 
individuals. As a result, the FAA has included all costs in this cost 
estimate.

Paperwork Reduction Act

    A federal agency may not conduct or sponsor, and a person is not 
required to respond to, nor shall a person be subject to a penalty for 
failure to comply with a collection of information subject to the 
requirements of the Paperwork Reduction Act unless that collection of 
information displays a currently valid OMB Control Number. The OMB 
Control Number for this information collection is 2120-0056. Public 
reporting for this collection of information is estimated to be 
approximately 2 hours per response, including the time for reviewing 
instructions, searching existing data sources, gathering and 
maintaining the data needed, completing and reviewing the collection of 
information. All responses to this collection of information are 
mandatory. Send comments regarding this burden estimate or any other 
aspect of this collection of information, including suggestions for 
reducing this burden to: Information Collection Clearance Officer, 
Federal Aviation Administration, 10101 Hillwood Parkway, Fort Worth, TX 
76177-1524.

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

    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), and
    (3) 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

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 (AD):

2020-12-06 Gulfstream Aerospace Corporation: Amendment 39-21141; 
Docket No. FAA-2019-1060; Product Identifier 2018-CE-020-AD.

(a) Effective Date

    This AD is effective July 20, 2020.

 (b) Affected ADs

    None.

(c) Applicability

    This AD applies to Gulfstream Aerospace Corporation Model G-IV 
airplanes, certificated in any category.

(d) Subject

    Joint Aircraft System Component (JASC)/Air Transport Association 
(ATA) of America Code 32, Landing Gear.

(e) Unsafe Condition

    This AD was prompted by reports of un-commanded nose wheel 
steering turns. The FAA is issuing this AD to prevent moisture from 
entering the nose steering wheel servo valve, which could freeze and 
cause an un-commanded nose wheel steering position during touchdown. 
The unsafe condition, if not addressed, could result in a lateral 
runway departure.

[[Page 36145]]

(f) Compliance

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

(g) Airplane Flight Manual Revisions

    Within 30 days after the effective date of this AD, revise your 
airplane flight manual (AFM) by incorporating the revision 
applicable to your airplane configuration as listed in paragraphs 
(g)(1) through (3) of this AD:
    (1) Gulfstream IV Airplane Flight Manual, Gulfstream Aerospace 
Document Number GAC-AC-GIV-OPS-0001, Revision 52, dated October 30, 
2017;
    (2) Gulfstream G300 Airplane Flight Manual, Gulfstream Aerospace 
Document Number GAC-AC-G300-OPS-0001, Revision 20, dated October 30, 
2017; or
    (3) Gulfstream G400 Airplane Flight Manual, Gulfstream Aerospace 
Document Number FAC-AC-G400-OPS-0001, Revision 20, dated October 30, 
2017.

(h) Replace the Nose Wheel Steering Servo Valve Manifold

    Within 36 months after the effective date of this AD, replace 
the nose wheel steering servo valve manifold with nose wheel 
steering servo valve manifold part number 5100-11 or 5105-5 in 
accordance with the Accomplishment Instructions of the customer 
bulletin that applies to your airplane configuration as listed in 
paragraphs (h)(1) through (3) of this AD, except you are not 
required to comply with step H:
    (1) Gulfstream IV Customer Bulletin Number 244, dated March 12, 
2018;
    (2) Gulfstream G300 Customer Bulletin 244, dated March 12, 2018; 
or
    (3) Gulfstream G400 Customer Bulletin 244, dated March 12, 2018.

(i) Records Inspection and Report of Results

    (1) Between 12 months and 24 months after the replacement of the 
nose wheel steering valve manifold assembly required in paragraph 
(h) of this AD, inspect all aircraft records for entries of an un-
commanded nose wheel steering turn.
    (2) Within 10 days after the records inspection required in 
paragraph (i)(1) of this AD, report the results of the inspection, 
regardless of whether the inspection found any entries, to the FAA 
by either email: <a href="/cdn-cgi/l/email-protection#457c6804160a6368041109060a16681720352a37312c2b22052324246b222a33"><span class="__cf_email__" data-cfemail="ecd5c1adbfa3cac1adb8a0afa3bfc1be899c839e9885828bac8a8d8dc28b839a">[email&#160;protected]</span></a>; or by mail: Attn: 
Continued Operational Safety, Atlanta ACO Branch, FAA, 1701 Columbia 
Avenue, College Park, Georgia 30337. The report must include as much 
of the information listed in paragraphs (i)(2)(i) through (vii) of 
this AD as is known about the event:
    (i) Date of records inspection;
    (ii) Date and time of all un-commanded occurrences (if any);
    (iii) Airplane serial number;
    (iv) Weather and runway conditions at the time of each 
occurrence;
    (v) Copy of the pilot's report of the occurrence (if available);
    (vi) Maintenance entry of the root cause of the un-commanded 
deflection (if available); and
    (vii) Any other information pertinent to the occurrence.

(j) Alternative Methods of Compliance (AMOCs)

    (1) The Manager, Atlanta 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 local Flight Standards District 
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 (k)(1) of this AD.
    (2) Before using any approved AMOC, notify your appropriate 
principal inspector, or lacking a principal inspector, the manager 
of the local flight standards district office/certificate holding 
district office.

(k) Related Information

    For more information about this AD, contact Alex Armas, 
Aerospace Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, 
College Park, Georgia 30337; phone: (404) 474-5538; fax: (404) 474-
5605; email: <a href="/cdn-cgi/l/email-protection#0869646d7026697a65697b486e6969266f677e"><span class="__cf_email__" data-cfemail="40212c25386e21322d2133002621216e272f36">[email&#160;protected]</span></a>.

(l) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference (IBR) of the service information listed 
in this paragraph under 5 U.S.C. 552(a) and 1 CFR part 51.
    (2) You must use this service information as applicable to do 
the actions required by this AD, unless the AD specifies otherwise.
    (i) Gulfstream IV Customer Bulletin Number 244, dated March 12, 
2018.
    (ii) Gulfstream G300 Customer Bulletin Number 244, dated March 
12, 2018.
    (iii) Gulfstream G400 Customer Bulletin Number 244, dated March 
12, 2018.
    (iv) Gulfstream IV Airplane Flight Manual, Gulfstream Aerospace 
Document Number GAC-AC-GIV-OPS-0001, Revision 52, dated October 30, 
2017.
    (v) Gulfstream G300 Airplane Flight Manual, Gulfstream Aerospace 
Document Number GAC-AC-G300-OPS-0001, Revision 20, dated October 30, 
2017.
    (vi) Gulfstream G400 Airplane Flight Manual, Gulfstream 
Aerospace Document Number FAC-AC-G400-OPS-0001, Revision 20, dated 
October 30, 2017.
    (3) For service information identified in this AD, contact 
Gulfstream Aerospace Corporation, P.O. Box 2206, Savannah, Georgia 
31402-2206; telephone: (800) 810-4853; fax 912-965-3520; email: 
<a href="/cdn-cgi/l/email-protection#d6a6a3b4a596b1a3bab0a5a2a4b3b7bbf8b5b9bb"><span class="__cf_email__" data-cfemail="e797928594a780928b8194939582868ac984888a">[email&#160;protected]</span></a>; internet: <a href="https://www.gulfstream.com/customer-support">https://www.gulfstream.com/customer-support</a>.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 901 Locust, Kansas 
City, Missouri 64106. For information on the availability of this 
material at the FAA, call (816) 329-4148.
    (5) You may view this service information that is incorporated 
by reference at the National Archives and Records Administration 
(NARA). For information on the availability of this material at 
NARA, email: <a href="/cdn-cgi/l/email-protection#fb9d9e9f899e9cd5979e9c9a97bb959a899ad59c948d"><span class="__cf_email__" data-cfemail="96f0f3f2e4f3f1b8faf3f1f7fad6f8f7e4f7b8f1f9e0">[email&#160;protected]</span></a>, or go to: <a href="https://www.archives.gov/federal-register/cfr/ibr-locations.html">https://www.archives.gov/federal-register/cfr/ibr-locations.html</a>.

    Issued on June 2, 2020.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2020-12812 Filed 6-12-20; 8:45 am]
 BILLING CODE 4910-13-P

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