Document ID: FAA-2020-0831-0003
Agency: faa
Document Type: Rule
Title: Airworthiness Directives: Gulfstream Aerospace Corporation Airplanes
Posted Date: 2021-03-30T04:00Z

[Federal Register Volume 86, Number 59 (Tuesday, March 30, 2021)]
[Rules and Regulations]
[Pages 16507-16509]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-06500]

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 Rules and Regulations
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  Federal Register / Vol. 86, No. 59 / Tuesday, March 30, 2021 / Rules 
and Regulations  

[[Page 16507]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2020-0831; Project Identifier 2019-CE-031-AD; Amendment 
39-21471; AD 2021-06-04]
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 GV airplanes. This 
AD was prompted by notification of corrosion present in floor beam 
support links. This AD requires inspecting the right butt line 6 floor 
beam inboard support links and bushings for corrosion. The FAA is 
issuing this AD to address the unsafe condition on these products.

DATES: This AD is effective May 4, 2021.
    The Director of the Federal Register approved the incorporation by 
reference of a certain publication listed in this AD as of May 4, 2021.

ADDRESSES: For service information identified in this final rule, 
contact Gulfstream Aerospace Corporation, Technical Publications Dept., 
P.O. Box 2206, Savannah, GA 31402-2206; phone: (800) 810-4853; fax: 
(912) 965-3520; email: pubs@gulfstream.com; website: https://www.gulfstream.com/en/customer-support/. You may view this service 
information at the FAA, Airworthiness Products Section, Operational 
Safety Branch, 901 Locust, Kansas City, MO 64106.
    For information on the availability of this material at the FAA, 
call (816) 329-4148. It is also available at https://www.regulations.gov by searching for and locating Docket No. FAA-2020-
0831.

Examining the AD Docket

    You may examine the AD docket at https://www.regulations.gov by 
searching for and locating Docket No. FAA-2020-0831; 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, any 
comments received, and other information. The 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: Ronald Wissing, Aviation Safety 
Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park, 
GA 30337; phone: (404) 474-5552; fax: (404) 474-5606; email: 
ronald.wissing@faa.gov.

SUPPLEMENTARY INFORMATION:

Background

    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 GV 
airplanes. The NPRM published in the Federal Register on December 10, 
2020 (85 FR 79443). The NPRM was prompted by notification of a failed 
floor beam support link at right butt line (RBL) 6 on a Gulfstream 
Model GV airplane, resulting from seizure of the retaining sleeve and 
bushing at the lower attachment point due to undetected corrosion.
    The floor beam support links at RBL 6, fuselage stations (FS) 499, 
531, and 569.5 have a two-piece installation with straight bushings 
rather than spherical bearings in the inboard link lower end. Design of 
the support links allows floor beam movement when the cabin is 
pressurized. Seizure of the lower bushing will not allow the link 
assembly to move as designed, resulting in bending stress and potential 
failure of the link, which may compromise the integrity of the pressure 
vessel floor. Gulfstream determined that the procedures for the 
existing Aircraft Maintenance Manual (AMM) inspection do not reliably 
detect corrosion in the floor beam support link lower bushings. 
Accordingly, Gulfstream has revised the airworthiness limitation 
requirements to the AMM by adding a detailed inspection with an initial 
and repetitive inspections at intervals of 96 months and including 
references for removal and installation instructions for RBL 6 Floor 
Beam Support Links.
    In the NPRM, the FAA proposed to require inspecting the right butt 
line 6 floor beam inboard support links and bushings for corrosion. The 
FAA is issuing this AD to prevent link failure, which can compromise 
the integrity of the pressure vessel floor and lead to loss of 
pressurization of the airplane.

Discussion of Final Airworthiness Directive

Comments

    The FAA received one comment from Gulfstream. The following 
presents the comment received on the NPRM and the FAA's response to the 
comment.

Request for Clarification on Reporting

    Gulfstream requested the FAA clarify whether the AD requires or 
recommends reporting the CB 231A inspection results to Gulfstream. 
Gulfstream noted a discrepancy in the NPRM, where the section titled 
``Proposed AD Requirements'' states that the proposed AD recommends 
sending the inspection results to Gulfstream, but the section titled 
``Differences Between this Proposed AD and the Service Information'' 
states that the proposed AD would not require reporting the results of 
the inspection to Gulfstream.
    The FAA agrees. This AD does not require reporting the results of 
the inspection. This AD is not an interim action; mandating a report of 
the inspection results is not necessary to correct the unsafe 
condition. The FAA should not have included conflicting language in the 
NPRM to this effect. The FAA has revised the preamble of this final 
rule to correct this discrepancy.

Conclusion

    The FAA reviewed the relevant data, considered any comments 
received, and determined that air safety requires adopting this AD as 
proposed. Accordingly, the FAA is issuing this AD to address the unsafe 
condition on these products. Except for minor editorial changes, this 
AD is adopted as proposed in the NPRM. None of the changes will 
increase the economic burden on any operator.

Related Service Information Under 1 CFR Part 51

    The FAA reviewed Gulfstream GV Customer Bulletin Number 231,

[[Page 16508]]

Revision A, dated July 30, 2019 (Gulfstream CB 231A). The service 
information contains procedures for the inspection of the RBL 6, FS 
499, 531, and 569.5, and the bushing in the lower end of the link and 
all attachments for corrosion.
    The FAA reviewed Table 13: Fuselage Inspection Table in Section 05-
10-10 of Chapter 5--Time Limits/Maintenance Checks of Gulfstream GV 
Aircraft Maintenance Manual, Revision 51, dated February 28, 2020. The 
service information identifies tasks for a recurring detailed 
inspection of the floor beam and wing links FS 465 through FS 576.
    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.

Differences Between This AD and the Service Information

    Gulfstream CB 231A specifies reporting the results of the 
inspection to Gulfstream, and this AD does not.

Costs of Compliance

    The FAA estimates that this AD affects 148 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
----------------------------------------------------------------------------------------------------------------
Inspection per the Customer         120 work-hours x $85   Not applicable.......         $10,200      $1,509,600
 Bulletin, all 3 locations.          per hour = $10,200.
Revise the AMM....................  1 work-hour x $85 per  Not applicable.......              85          12,580
                                     hour = $85.
----------------------------------------------------------------------------------------------------------------

    The FAA estimates the following costs to do any necessary 
replacements that would be required based on the results of the 
inspection. The FAA has no way of determining the number of airplanes 
that might need these replacements:

                                               On-Condition Costs
----------------------------------------------------------------------------------------------------------------
                                                                                                     Cost per
                    Action                                Labor cost               Parts cost        product
----------------------------------------------------------------------------------------------------------------
Replacement of all 3 links...................  40 work-hours x $85 per hour =             $316           $3,716
                                                $3,400.
----------------------------------------------------------------------------------------------------------------

    The FAA has included all known costs in its cost estimate. 
According to the manufacturer, however, some of the costs of this AD 
may be covered under warranty, thereby reducing the cost impact on 
affected operators.

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) Will not affect intrastate aviation in Alaska, 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.

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:

2021-06-04 Gulfstream Aerospace Corporation: Amendment 39-21471; 
Docket No. FAA-2020-0831; Project Identifier 2019-CE-031-AD.

(a) Effective Date

    This airworthiness directive (AD) is effective May 4, 2021.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Gulfstream Aerospace Corporation Model GV 
airplanes, all serial numbers, certificated in any category.

(d) Subject

    Air Transport Association of America (ATA) Code 53: Fuselage 
Structure.

(e) Reason

    This AD was prompted by a report that current inspection 
procedures of floor beam support links, which can fail due to 
corrosion, are inadequate. The FAA is issuing this AD to detect and 
correct corrosion on a floor beam support link lower bushing. This 
condition, if not addressed, could result in link failure, which can 
compromise the integrity of the pressure vessel floor and lead to 
loss of pressurization of the airplane.

[[Page 16509]]

(f) Compliance

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

(g) Actions

    (1) Within 24 months after the effective date of this AD, 
inspect the right butt line 6 floor beam inboard support links at 
fuselage stations (FS) 499, 531, and 569.5 for corrosion by 
following the Accomplishment Instructions, steps A through M, of 
Gulfstream GV Customer Bulletin No. 231, Revision A, dated July 30, 
2019 (Gulfstream CB 231A). Where Gulfstream CB 231A specifies 
contacting Gulfstream for procedures if any corrosion is found, you 
must replace the support link in accordance with a method approved 
by the Manager, Atlanta ACO Branch, FAA, before further flight. For 
a method to be approved by the Manager, Atlanta ACO Branch, as 
required by this paragraph, the Manager's approval letter must 
specifically refer to this AD.
    (2) Within 24 months after the effective date of this AD, revise 
the airworthiness limitations section of your maintenance manual or 
inspection program to incorporate the airworthiness limitations 
specified in Table 13: Fuselage Inspection Table in Section 05-10-10 
of Chapter 5--Time Limits/Maintenance Checks of Gulfstream GV 
Aircraft Maintenance Manual, Revision 51, dated February 28, 2020. 
Thereafter, except as provided in paragraph (h) of this AD, no 
alternative inspection intervals may be approved for the fuselage 
floor beam and wing link FS 465-FS 576.

(h) 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 (i)(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.
    (3) For service information that contains steps that are labeled 
as Required for Compliance (RC), the following provisions apply.
    (i) The steps labeled as RC, including substeps under an RC step 
and any figures identified in an RC step, must be done to comply 
with the AD. An AMOC is required for any deviations to RC steps, 
including substeps and identified figures.
    (ii) Steps not labeled as RC may be deviated from using accepted 
methods in accordance with the operator's maintenance or inspection 
program without obtaining approval of an AMOC, provided the RC 
steps, including substeps and identified figures, can still be done 
as specified, and the airplane can be put back in an airworthy 
condition.

(i) Related Information

    For more information about this AD, contact Ronald Wissing, 
Aviation Safety Engineer, Atlanta ACO Branch, FAA, 1701 Columbia 
Avenue, College Park, GA 30337; phone: (404) 474-5552; fax: (404) 
474-5606; email: ronald.wissing@faa.gov.

(j) Material Incorporated by Reference

    (1) The Director of the Federal Register approved the 
incorporation by reference 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 GV Customer Bulletin Number 231, Revision A, 
dated July 30, 2019.
    (ii) Table 13: Fuselage Inspection Table in Section 05-10-10 of 
Chapter 5--Time Limits/Maintenance Checks of Gulfstream GV Aircraft 
Maintenance Manual, Revision 51, dated February 28, 2020.
    (3) For Gulfstream Aerospace Corporation service information 
identified in this AD, contact Gulfstream Aerospace Corporation, 
Technical Publications Dept., P.O. Box 2206, Savannah, GA 31402-
2206; phone: (800) 810-4853; fax: (912) 965-3520; email: 
pubs@gulfstream.com; website: https://www.gulfstream.com/en/customer-support/.
    (4) You may view this service information at FAA, Airworthiness 
Products Section, Operational Safety Branch, 901 Locust, Kansas 
City, MO 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: fedreg.legal@nara.gov, or go to: https://www.archives.gov/federal-register/cfr/ibr-locations.html.

    Issued on March 5, 2021.
Lance T. Gant,
Director, Compliance & Airworthiness Division, Aircraft Certification 
Service.
[FR Doc. 2021-06500 Filed 3-29-21; 8:45 am]
BILLING CODE 4910-13-P