Airworthiness Directives; Gulfstream Model G-IV, GIV-X, and GV-SP Series Airplanes and Model GV Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Gulfstream Model G-IV, GIV-X, GV-SP series airplanes and Model GV airplanes. This AD requires, for certain airplanes, a one-time inspection for sealant applied to the exterior of the auxiliary power unit (APU) enclosure (firewall), and, for airplanes with the subject sealant and certain other airplanes, a revision of the airplane flight manual to prohibit operation of the APU during certain ground and flight operations. This AD results from notification from the airplane manufacturer that an improper, flammable sealant was used on the interior and exterior of the APU enclosure (firewall). We are issuing this AD to prevent this flammable sealant from igniting the exterior surfaces of the APU enclosure (firewall) under certain anomalous conditions such as an APU failure/APU compartment fire, which could result in propagation of an uncontained fire to other critical areas of the airplane.

DATES:

This AD is effective August 26, 2009.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of August 26, 2009.

We must receive comments on this AD by October 13, 2009.

ADDRESSES:

You may send comments 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 AD, contact Gulfstream Aerospace Corporation, Technical Publications Dept., P.O. Box 2206, Savannah, Georgia 31402-2206; telephone 800-810-4853; fax 912-965-3520; e-mail pubs@gulfstream.com; Internet http://www.gulfstream.com/product_support/technical_pubs/pubs/index.htm.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov ; 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 street address for the Docket Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Sanford Proveaux, Aerospace Engineer, Propulsion and Services Branch, ACE-118A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; telephone (770) 703-6049; fax (770) 703-6097.

SUPPLEMENTARY INFORMATION:

Discussion

The manufacturer has notified us that an improper, flammable sealant (GMS 4107) was used on interior angles formed by sheet intersections and titanium sheet mating surfaces of the auxiliary power unit (APU) enclosure (firewall). This flammable sealant was also used to coat rivet heads on the interior and exterior surfaces of the APU enclosure (firewall). In some places the sealant was used by design, and in other places it was used in error. This sealant could ignite the exterior surfaces of the APU enclosure (firewall) under certain anomalous conditions such as an APU failure/APU compartment fire. This condition, if not corrected, could result in propagation of an uncontained fire to other critical areas of the airplane.

Relevant Service Information

We reviewed the Gulfstream alert customer bulletins listed in the following table. The alert customer bulletins for Model G-IV series airplanes and Model GV airplanes describe procedures for a one-time inspection of the APU enclosure (firewall) for overcoat application of the flammable sealant on rivets or fillet seals on panel joints. For Model GIV-X and GV-SP series airplanes, and airplanes with flammable sealant found during the inspection, the alert customer bulletins describe revising the applicable airplane flight manual (AFM) and reporting compliance to Gulfstream.

FAA's Determination and Requirements of This AD

We are issuing 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 these same type designs. This AD requires accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between the AD and the Service Information.”

Differences Between the AD and the Service Information

Although the Gulfstream alert customer bulletins specified in the table titled “Table 1—Applicable alert customer bulletins including airplane flight manual (AFM) supplements, and AFMs” of this AD specify to submit information to the manufacturer, this AD does not include such a requirement.

Although certain Gulfstream alert customer bulletins specified in the table titled “Table 1—Applicable alert customer bulletins including airplane flight manual (AFM) supplements, and AFMs” of this AD specify only to “inspect” for flammable sealant on the APU enclosure (firewall), we have determined that the procedures in those Gulfstream alert customer bulletins should be described as a “general visual inspection.” Note 1 has been included in this AD to define this type of inspection.

Clarification of Statement in Gulfstream Alert Customer Bulletins

The Gulfstream alert customer bulletins specified in the table titled “Table 1—Applicable alert customer bulletins including airplane flight manual (AFM) supplements, and AFMs” of this AD include a statement in the Accomplishment Instructions to inform operators to contact Gulfstream “if technical assistance is required” in accomplishing the actions specified in the alert customer bulletins. We have included Note 2 in this AD to clarify that any deviation from the instructions provided in the applicable alert customer bulletin must be approved as an alternative method of compliance under the provisions of paragraph (l) of this AD.

Interim Action

We consider this AD interim action. If final action is later identified, we might consider further rulemaking then.

FAA's Justification and Determination of the Effective Date

The use of flammable sealant in the construction of the primary APU enclosure (firewall) compromises the integrity of the enclosure (firewall). If an APU fire occurs, the flammable sealant can ignite the exterior of the APU enclosure (firewall). This area is very confined and surrounded by primary airframe structure that carries the empennage loads. Primary flight controls for pitch and yaw are routed through the area adjacent to the APU enclosure (firewall). Because of our requirement to promote safe flight of civil aircraft and thus the critical need to assure the structural integrity and proper functioning of the APU enclosure (firewall), and the short compliance time involved with this action, this AD must be issued immediately.

Because an unsafe condition exists that requires the immediate adoption of this AD, we find that notice and opportunity for prior public comment hereon are impracticable and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

This AD is a final rule that involves requirements affecting flight safety, and we did not provide you with notice and an opportunity to provide your comments before it becomes effective. However, we invite you to send any written data, views, or arguments about this AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2009-0683; Directorate Identifier 2009-NM-129-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this AD. We will consider all comments received by the closing date and may amend this AD 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 AD.

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), 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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

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.

2. The FAA amends § 39.13 by adding the following new AD:

2009-17-01 Gulfstream Aerospace Corporation: Amendment 39-15991. Docket No. FAA-2009-0683; Directorate Identifier 2009-NM-129-AD.

Effective Date

(a) This airworthiness directive (AD) is effective August 26, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the Gulfstream airplanes identified in paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) of this AD, certificated in any category.

(1) Model G-IV series airplanes, having serial numbers (S/Ns) 1000 and subsequent.

(2) Model GIV-X series airplanes, having S/Ns 4001 through 4146 inclusive, and S/Ns 4148 through 4150 inclusive.

(3) Model GV airplanes, having S/Ns 501 and subsequent.

(4) Model GV-SP series airplanes, having S/Ns 5001 through 5204 inclusive, S/Ns 5206 through 5217 inclusive, and S/N 5219.

Subject

(d) Air Transport Association (ATA) of America Codes 53: Fuselage, and 49: Airborne Auxiliary Power.

Unsafe Condition

(e) This AD results from notification from the airplane manufacturer that an improper, flammable sealant was used on the interior and exterior of the auxiliary power unit (APU) enclosure (firewall). The Federal Aviation Administration is issuing this AD to prevent this flammable sealant from igniting the exterior surfaces of the APU enclosure (firewall) under certain anomalous conditions such as an APU failure/APU compartment fire, which could result in propagation of an uncontained fire to other critical areas of the airplane.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Inspection for Flammable Sealant

(g) For Model G-IV series airplanes identified in paragraph (c)(1) of this AD, and Model GV airplanes identified in paragraph (c)(3) of this AD: Within 21 days after the effective date of this AD, except as provided by paragraph (k) of this AD, perform a general visual inspection of the exterior of the APU enclosure (firewall) to detect overcoat application of sealant on rivets or fillet seals on panel joints, in accordance with the Accomplishment Instructions of the applicable Gulfstream alert customer bulletin specified in Table 1 of this AD.

(1) If no exterior sealant is found applied during the inspection done in accordance with paragraph (g) of this AD: No further action is required by this paragraph.

(2) If exterior sealant is found applied during the inspection done in accordance with paragraph (g) of this AD: Do the actions specified in paragraph (h) of this AD.

Note 1:

For the purposes of this AD, a general visual inspection is: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to ensure visual access to all surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

Note 2:

A statement in the Accomplishment Instructions of the applicable Gulfstream alert customer bulletins specified in Table 1 of this AD instructs operators to contact Gulfstream if technical assistance is needed in accomplishing the alert customer bulletin. However, any deviation from the instructions provided in the applicable alert customer bulletin must be approved as an alternative method of compliance under paragraph (l) of this AD.

Revision of the AFM

(h) For Model GIV-X series airplanes identified in paragraph (c)(2) of this AD, Model GV-SP series airplanes identified in paragraph (c)(4) of this AD, and Model G-IV series airplanes and Model GV airplanes with flammable sealant on the exterior of the APU enclosure (firewall) identified during the inspection required by paragraph (g) of this AD: At the applicable time specified in paragraph (h)(1) or (h)(2) of this AD, revise the Limitations Section of the applicable Gulfstream AFM specified in Table 1 of this AD to include the information in the applicable Gulfstream AFM supplement specified in Table 1 of this AD. These AFM supplements introduce limitations on the use of the APU during certain ground and flight operations.

Note 3:

This AFM revision may be done by inserting a copy of the applicable AFM supplement into the applicable AFM specified in Table 1 of this AD. When the supplement has been included in the general revisions of the AFM, the general revisions may be inserted in the AFM, provided the relevant information in the general revision is identical to that in the applicable AFM supplement specified in Table 1 of this AD.

(1) For Model G-IV series airplanes and Model GV airplanes with flammable sealant on the exterior of the APU enclosure (firewall) identified during the inspection required by paragraph (g) of this AD: Prior to further flight following the inspection done in accordance with paragraph (g) of this AD.

(2) For Model GIV-X series airplanes identified in paragraph (c)(2) of this AD, and Model GV-SP series airplanes identified in paragraph (c)(4) of this AD: Within 21 days after the effective date of this AD.

Credit for Actions Done Using Previous Service Information

(i) Inspecting for flammable sealant and revising the AFM before the effective date of this AD using the applicable alert customer bulletin and AFM supplement specified in Table 2 of this AD are acceptable for compliance with the corresponding actions specified in this AD.

No Reporting Required

(j) Although the Gulfstream alert customer bulletins specified in Table 1 of this AD specify to submit information to the manufacturer, this AD does not include this requirement.

Parts Installation

(k) As of the effective date of this AD, no person may install an APU enclosure (firewall) that contains flammable sealant (GMS 4107) in the construction, on any airplane.

Alternative Methods of Compliance (AMOCs)

(l)(1) The Manager, Atlanta Aircraft Certification Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Sanford Proveaux, Aerospace Engineer, Propulsion and Services Branch, ACE-118A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; telephone (770) 703-6049; fax (770) 703-6097.

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

Material Incorporated by Reference

(m) You must use the service information contained in Table 3 of this AD to do the actions required by this AD, as applicable, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Gulfstream Aerospace Corporation, Technical Publications Dept., P.O. Box 2206, Savannah, Georgia 31402-2206; telephone 800-810-4853; fax 912-965-3520; e-mail pubs@gulfstream.com; Internet http://www.gulfstream.com/product_support/technical_pubs/pubs/index.htm .

(3) You may review copies of the service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221 or 425-227-1152.

(4) You may also review copies of the 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, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html .