E7-24335. Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD requires repetitive detailed and high-frequency eddy current inspections for cracking around the heads of the fasteners on the forward fastener row of certain areas of the station (STA) 259.5 circumferential butt splice, and repair if necessary. This AD also requires a preventive modification, which eliminates the need for the repetitive inspections. This AD results from a report that an operator found multiple cracks in the fuselage skin of a Model 737-200 airplane, at the forward fastener row of the STA 259.5 circumferential butt splice between stringers 19 and 24. We are issuing this AD to prevent cracking of the STA 259.5 circumferential butt splice, which could result in loss of structural integrity of the fuselage skin and possible loss of cabin pressure.

DATES:

This AD is effective January 22, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of January 22, 2008.

ADDRESSES:

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

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 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:

Wayne Lockett, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; 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 737-100, -200, -200C, -300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on August 16, 2007 (72 FR 45949). That NPRM proposed to require repetitive detailed and high-frequency eddy current inspections for cracking around the heads of the fasteners on the forward fastener row of certain areas of the station (STA) 259.5 circumferential butt splice, and repair if necessary. That NPRM also proposed to require a preventive modification, which would eliminate the need for the repetitive inspections.

Comments

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

Conclusion

We reviewed the relevant data, considered the comment received, and determined that air safety and the public interest require adopting the AD as proposed.

Costs of Compliance

There are about 2,150 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD, at an average labor rate of $80 per work hour. Required parts will be supplied by the operator.

Estimated Costs

Action	Work hours	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Inspection	5	$400, per inspection cycle	654	$261,600, per inspection cycle.
Preventive modification	24	$1,920	654	$1,255,680.

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:

2007-26-04 Boeing: Amendment 39-15306. Docket No. FAA-2007-28942; Directorate Identifier 2007-NM-093-AD.

Effective Date

(a) This airworthiness directive (AD) is effective January 22, 2008.

Affected ADs

(b) Accomplishing repairs and modifications described in paragraphs (f) and (g) of this AD is considered acceptable for compliance with repair requirements of paragraphs (f) and (g) of AD 92-25-09, amendment 39-8424, for the areas of the station (STA) 259.5 circumferential butt splice only.

Applicability

(c) This AD applies to Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category, as identified in Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006.

Unsafe Condition

(d) This AD results from a report that an operator found multiple cracks in the fuselage skin of a Model 737-200 airplane, at the forward fastener row of the STA 259.5 circumferential butt splice between stringers 19 and 24. We are issuing this AD to prevent cracking of the STA 259.5 circumferential butt splice, which could result in loss of structural integrity of the fuselage skin and possible loss of cabin pressure.

Compliance

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

Inspections

(f) At the applicable initial compliance time specified in paragraph 1.E. “Compliance” of Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006, except as provided by paragraph (j) of this AD: Do detailed and high-frequency eddy current inspections for cracking around the heads of the fasteners on the forward fastener row of certain areas of the STA 259.5 circumferential butt splice, by doing all of the actions specified in Part 1 of the Accomplishment Instructions of the service bulletin, except as provided by paragraph (i) of this AD. Repeat the inspections thereafter at the intervals specified in paragraph 1.E. of the service bulletin. Doing the preventive modification specified in paragraph (h) of this AD terminates the repetitive inspection requirements of this paragraph.

Repair

(g) If any crack is found during any inspection required by this AD, before further flight, repair in accordance with Part 1 of the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006.

Preventive Modification

(h) At the compliance time specified in paragraph 1.E. of Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006, except as provided by paragraph (j) of this AD: Do the preventive modification in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006. Doing the preventive modification terminates the repetitive inspections required by paragraph (f) of this AD.

Modification or Repair Done in Accordance With AD 92-25-09

(i) Inspections described in paragraph (f) of this AD are not required for areas of the STA 259.5 circumferential butt splice that have been modified in accordance with the service information specified in Table 1 of this AD. (Boeing Service Bulletin 737-53-1076, Revision 2, dated February 8, 1990; and Revision 4, dated September 26, 1991; are cited as appropriate sources of service information for doing certain requirements of AD 92-25-09.)

Table 1.—Service Information

Boeing Service Bulletin—	Revision level—	Date—
737-53-1076	4	September 26, 1991.
737-53-1076	3	September 20, 1990.
737-53-1076	2	February 8, 1990.
737-53-1076	1	November 23, 1988.
737-53-1076	Original	October 30, 1986.

Compliance Times

(j) Where Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006, specifies compliance times relative to the release date of the service bulletin, this AD requires compliance at compliance times relative to the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

(k)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(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 appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who has been authorized by the Manager, Seattle ACO, to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane, and the approval must specifically refer to this AD.

Material Incorporated by Reference

(l) You must use Boeing Special Attention Service Bulletin 737-53-1267, dated November 28, 2006, to do the actions required by this AD, 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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

(3) You may review copies of the service information incorporated by reference at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or 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 December 10, 2007.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.