E9-23509. Airworthiness Directives; Boeing Model 737-300, -400, and -500 Series Airplanes Equipped With a Digital Transient Suppression Device (DTSD) Installed in Accordance With Supplemental Type Certificate (STC) ST00127BO

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, and -500 series airplanes. This AD requires revising the maintenance program to include new fuel system limitations for airplanes modified in accordance with STC ST00127BO. This AD also requires inspections and checks of the DTSDs and corrective actions, if necessary. This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent a potential of ignition sources inside fuel tanks, which, in combination with flammable fuel vapors, could result in a fuel tank fire or explosion and consequent loss of the airplane.

DATES:

This AD is effective November 5, 2009.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of November 5, 2009.

ADDRESSES:

For service information identified in this AD, contact Goodrich Corporation, Fuel and Utility Systems, 100 Panton Road, Vergennes, Vermont 05491-1008; telephone [phone]; e-mail [e-mail]; Internet http://www.goodrich.com/​TechPubs.

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 address for the Docket Office (telephone [phone]) is the Document 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:

Marc Ronell, Aerospace Engineer, ANE-150, FAA, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, Massachusetts 01803; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain Boeing Model 737-300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on June 9, 2009 (74 FR 27254). That NPRM proposed to require revising the maintenance program to include new fuel system limitations for airplanes modified in accordance with Supplemental Type Certificate (STC) ST00127BO. That NPRM also proposed to require inspections and checks of the digital transient suppression devices and corrective actions, if necessary.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comment received. Boeing supports the NPRM.

Actions Since NPRM was Issued

Since we issued the NPRM, we have determined that it is necessary to clarify the AD's intended effect on spare and on-airplane fuel tank system components, regarding the use of maintenance manuals and instructions for continued airworthiness.

Section 91.403(c) of the Federal Aviation Regulations (14 CFR 91.403(c)) specifies the following:

No person may operate an aircraft for which a manufacturer's maintenance manual or instructions for continued airworthiness has been issued that contains an airworthiness limitation section unless the mandatory * * * procedures * * * have been complied with.

Some operators have questioned whether existing components affected by the new CDCCLs must be reworked. We did not intend for the AD to retroactively require rework of components that had been maintained using acceptable methods before the effective date of the AD. Owners and operators of the affected airplanes therefore are not required to rework affected components identified as airworthy or installed on the affected airplanes before the required revisions of the maintenance program. But once the CDCCLs are incorporated into the maintenance program, future maintenance actions on components must be done in accordance with those CDCCLs.

We have added Note 2 to this AD to clarify the intended effect of the AD on spare and on-airplane fuel tank system components.

Conclusion

We reviewed the relevant data, including the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously. We also determined that this change will not increase the economic burden on any operator or increase the scope of the AD.

Costs of Compliance

We estimate that this AD affects 12 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this AD. The average labor rate is $80 per work hour.

Estimated Costs

Action	Work hours	Cost per product	Fleet cost
Revision to maintenance program	8	$640	$7,680
Operational check, per cycle	1	80	960
Bond damage inspection, per cycle	1	80	960
Separation inspection, per cycle	1	80	960

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.

§ 39.13

[Amended]

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

2009-20-11 Boeing: Amendment 39-16034. Docket No. FAA-2009-0521; Directorate Identifier 2008-NM-187-AD.

Effective Date

(a) This airworthiness directive (AD) is effective November 5, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 737-300, -400, and -500 series airplanes, certificated in any category, equipped with a digital transient suppression device (DTSD) installed in accordance with Supplemental Type Certificate (STC) ST00127BO.

Note 1:

This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance according to paragraph (m) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane.

Subject

(d) Air Transport Association (ATA) of America Code 28: Fuel.

Unsafe Condition

(e) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent a potential of ignition sources inside fuel tanks, which in combination with flammable fuel vapors, could result in a fuel tank fire or explosion and consequent loss 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.

Revision to the Maintenance Program to Add Critical Design Configuration Control Limitations (CDCCLs) Specified in Section 10.1 of the Service Information

(g) Within 30 days after the effective date of this AD: Revise the maintenance program to incorporate the fuel system limitations specified in Section 10.1 of the Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007.

Revision to the Maintenance Program to Add Scheduled Inspections/Operational Checks

(h) Within 30 days after the effective date of this AD: Revise the maintenance program to incorporate the scheduled inspections/operational checks specified in Section 2.2.3 of the Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007; except that the initial inspections/checks required by paragraphs (i), (j), and (k) of this AD must be done at the compliance times specified in those paragraphs. Repeat the inspections/checks thereafter at the applicable compliance times in the column, “Frequency,” of the table specified in Section 2.2.3 of the Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007.

Initial Inspections and Repair if Necessary

(i) Prior to the accumulation of 39,000 flight hours after modification in accordance with STC ST00127BO, or within 12 months after the effective date of this AD, whichever occurs later: Do an operational check of the DTSDs, in accordance with Section 2.2.3, “Scheduled Inspections/Operational Checks,” of the Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007. If the DTSD fails the operational check, repair before further flight, in accordance with the section of the Goodrich Aircraft Maintenance Manual Supplement with Wiring Diagrams, 737-300/-400/-500 FQIS with Goodrich Digital Indicators and Transient Suppression Device, STC Number: ST00127BO, Revision 5, dated December 20, 2006, that corresponds to the operational check specified in Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007.

(j) Prior to the accumulation of 4,000 flight hours after modification in accordance with STC ST00127BO, or within 6 months after the effective date of this AD, whichever occurs later: Do a general visual inspection for critical bond damage of the DTSD safe-side harnesses (critical bond damage includes measuring the bonding resistance across the ground strap and verifying the resistance is less than 2.0 milliohms), in accordance with Section 2.2.3, “Scheduled Inspections/Operational Checks,” of Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007, which includes Items 5, 6, 7, and 8 of Table 6 in Section 10.1, “Fuel System Limitations.” If any damage is found, repair before further flight, in accordance with the section of the Goodrich Aircraft Maintenance Manual Supplement with Wiring Diagrams for 737-300/-400/-500 FQIS with Goodrich Aircraft Maintenance Manual Supplement with Wiring Diagrams, 737-300/-400/-500 FQIS with Goodrich Digital Indicators and Transient Suppression Device, STC Number: ST00127BO, Revision 5, dated December 20, 2006, that corresponds to the general visual inspection specified in Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007.

(k) Prior to the accumulation of 24,000 flight hours after modification in accordance with STC ST00127BO, or within 12 months after the effective date of this AD, whichever occurs later: Do a general visual inspection for physical separation of the DTSD safe-side harnesses from other airplane wiring, hydraulic tubing, structure, control cables, and bleed air ducts, in accordance with Section 2.2.3, “Scheduled Inspections/Operational Checks,” of the Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007. If any damage is found, repair before further flight, in accordance with the section of the Goodrich Aircraft Maintenance Manual Supplement with Wiring Diagrams for 737-300/-400/-500 FQIS with Goodrich Digital Indicators and Transient Suppression Device, STC Number: ST00127BO, Revision 5, dated December 20, 2006, that corresponds to the general visual inspection specified in Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101, Revision D, dated January 16, 2007.

No Alternative Inspections/Checks, Inspection/Check Intervals, or CDCCLs

(l) After accomplishing the actions specified in paragraphs (g) and (h) of this AD, no alternative inspections/checks, inspection/check intervals, or CDCCLs may be used unless the inspections/checks, intervals, or CDCCLs are approved as an alternative method of compliance (AMOC) in accordance with the procedures specified in paragraph (m) of this AD.

Note 2:

Notwithstanding any other maintenance or operational requirements, components that have been identified as airworthy or installed on the affected airplanes before the revision of the maintenance program, as required by paragraph (g) of this AD, do not need to be reworked in accordance with the CDCCLs. However, once the maintenance program has been revised, future maintenance actions on these components must be done in accordance with the CDCCLs.

AMOCs

(m)(1) The Manager, Boston 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: Marc Ronell, Aerospace Engineer, ANE-150, FAA, Boston Aircraft Certification Office, 12 New England Executive Park, Burlington, Massachusetts 01803; telephone [phone]; fax [phone].

(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

(n) You must use the service information contained in Table 1 of this AD to do the actions required by this AD, as applicable, unless the AD specifies otherwise.

Table 1—Material Incorporated by Reference

Document	Revision	Date
Goodrich Aircraft Maintenance Manual Supplement with Wiring Diagrams, 737-300/-400/-500 FQIS with Goodrich Digital Indicators and Transient Suppression Device, STC Number: ST00127BO	5	December 20, 2006.
Goodrich Instructions for Continued Airworthiness for the Transient Suppression Device Installation Applicable to Boeing 737-300, -400, & -500 Airplanes Supplemental Type Certificate—ST00127BO, Document T2007-0010-0101	D	January 16, 2007.

(The List of Effective Pages (LOEP) for Goodrich Aircraft Maintenance Manual Supplement with Wiring Diagrams, 737-300/-400/-500 FQIS with Goodrich Digital Indicators and Transient Suppression Device, STC Number: ST00127BO, contains the following errors: Page TOC-1 is dated December 20, 2006, not June 1, 2002, as indicated in the LOEP; the odd-numbered pages of the Appendix—Wiring Diagrams are dated April 16, 2004, not August 15, 2005, as indicated in the LOEP.)

(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 Goodrich Corporation, Fuel and Utility Systems, 100 Panton Road, Vergennes, Vermont 05491-1008; telephone [phone]; e-mail [e-mail]; Internet http://www.goodrich.com/​TechPubs.

(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.

Issued in Renton, Washington, on September 18, 2009.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.