Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes; Federal Register Extracts

SUMMARY: The FAA is superseding an existing airworthiness directive (AD) that applies to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD currently requires repetitive inspections of the intercostal webs, attachment clips, and stringer splice channels for cracks; and corrective action if necessary. This new AD reduces the repetitive inspection intervals from 25,000 flight cycles to 6,000 flight cycles, and expands the inspection area for Model 737-200C series airplanes to include the area aft of the forward entry door. This AD results from additional reports of fatigue cracks. We are issuing this AD to detect and correct fatigue cracking of the intercostals on the forward and aft sides of the forward entry door, which could result in loss of the forward entry door and rapid decompression of the airplane.

DATES: This AD becomes effective September 9, 2009.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of September 9, 2009.

ADDRESSES: For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data and Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone 206-544-5000, extension 1; fax 206-766-5680; e-mail [email protected]; Internet https://www.myboeingfleet.com.

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 800-647-5527) 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: Alan Pohl, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6450; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that supersedes AD 2005-20-03, amendment 39-14296 (70 FR 56361, September 27, 2005). The existing AD applies to certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on November 17, 2008 (73 FR 67815). That NPRM proposed to continue to require repetitive inspections of the intercostal webs, attachment clips, and stringer splice channels for cracks, at repetitive inspection intervals reduced from 25,000 flight cycles to 6,000 flight cycles; and corrective action if necessary. That NPRM also proposed to expand the inspection area for Model 737-200C series airplanes to include the area aft of the forward entry door.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been received on the NPRM.

Request to Increase Grace Period

US Airways requests that we increase the threshold grace period from 3,000 flight cycles after the effective date of this AD to 4,500 flight cycles. US Airways states that the new grace period it requests would allow operators to schedule more airplanes into appropriate maintenance tasks. US Airways explains that the inspection would affect its operation by requiring additional maintenance that is not presently scheduled.

We do not agree with the commenter's request. In developing an appropriate compliance time for this AD, we considered not only the safety implications, but the manufacturer's recommendations, and the practical aspect of accomplishing the modification within an interval of time that corresponds to typical scheduled maintenance for affected operators. However, under the provisions of paragraph (m) of this AD, we may consider requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. We have not changed this AD in this regard.

Explanation of Additional Changes to the AD

We have clarified paragraphs (h), (i), and (l) of this AD to include the full citation for the service information referenced in those paragraphs. We made this change to ensure that it is clear which service information operators must use for a specific action.

We have changed paragraph (j) of this AD to remove the reference to "Part 4 of the Work Instructions of Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003," because that service bulletin does not contain a Part 4. Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007, does include Part 4 to provide procedures related to inspections and corrective actions for the intercostal webs and attachment clips located aft of the forward entry door. Boeing Special Attention Service Bulletin 737-53-1204, dated June 19, 2003, does not include any actions for this area of the airplane.

Conclusion

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

Costs of Compliance

There are about 3,132 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.

.... Estimated Costs

Action............Work hours..Average.... Cost per....Number of.. Fleet cost

..............................labor rate..airplane....U.S.-

..............................per hour................registered

......................................................airplanes

Inspection of.... 2............$80........ $160 per.. 876..........$140,160

areas forward of..........................inspection..............per

the aft entry............................ cycle.................. inspection

door (required by................................................ cycle.

AD 2005-20-03)

Inspection of.... 1.......... 80..........80 per......19..........1,520 per

areas aft of the..........................inspection..............inspection

forward entry............................ cycle.................. cycle.

door for Model

737-200C series

airplanes (new

action)

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

We have determined that 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

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.

SEC 39.13 [Amended]

2. The Federal Aviation Administration (FAA) amends SEC 39.13 by removing amendment 39-14296 (70 FR 56361, September 27, 2005) and by adding the following new airworthiness directive (AD):

2009-16-14 Boeing: Amendment 39-15987. Docket No. FAA-2008-1213; Directorate Identifier 2007-NM-092-AD.

Effective Date

(a) This AD becomes effective September 9, 2009.

Affected ADs

(b) This AD supersedes AD 2005-20-03.

Applicability

(c) This AD applies to Model 737-100, -200, -200C, -300, -400, and -500 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 737-53A1204, Revision 1, dated March 26, 2007.

Unsafe Condition

--This is a summary of a Federal Register article originally published on the page number listed below--

Final rule.

CFR Part: "14 CFR Part 39"

RIN Number: "RIN 2120-AA64"

Citation: "74 FR 38901"

Document Number: "Docket No. FAA-2008-1213; Directorate Identifier 2007-NM-092-AD; Amendment 39-15987; AD 2009-16-14"

Federal Register Page Number: "38901"

"Rules and Regulations"