E8-25893. Airworthiness Directives; Boeing Model 737-100, -200, -200C, -300, -400, and -500 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule; request for comments.

SUMMARY:

The FAA is revising 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 various repetitive inspections for cracking of the upper frame to side frame splice of the fuselage, and other specified and corrective actions if necessary. That AD also provides for an optional preventive modification, which terminates the repetitive inspections. This new AD adds an optional terminating action that was inadvertently omitted from that AD. This AD results from a report that the upper frame of the fuselage was severed between stringers S-13L and S-14L at station 747, and the adjacent frame at station 767 had a 1.3-inch-long crack at the same stringer location. We are issuing this AD to detect and correct fatigue cracking of the upper frame to side frame splice of the fuselage, which could result in reduced structural integrity of the frame and adjacent lap joint. This reduced structural integrity can increase loading in the fuselage skin, which will accelerate skin crack growth and result in decompression of the airplane.

DATES:

Effective December 1, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of December 1, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain other publication listed in this AD on August 12, 2008 (73 FR 38905, July 8, 2008).

We must receive comments on this AD by January 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: [phone].
• 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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207; telephone [phone]; fax [phone]; e-mail [e-mail]; 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 street address for the Docket Office (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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

On June 12, 2008, we issued AD 2008-13-12, amendment 39-15575 (73 FR 38905, July 8, 2008), for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. That AD requires various repetitive inspections for cracking of the upper frame to side frame splice of the fuselage, and other specified and corrective actions if necessary. That AD also provides for an optional preventive modification, which terminates the repetitive inspections. That AD resulted from a report that the upper frame of the fuselage was severed between stringers S-13L and S-14L at station 747, and the adjacent frame at station 767 had a 1.3-inch-long crack at the same stringer location. We issued that AD to detect and correct fatigue cracking of the upper frame to side frame splice of the fuselage, which could result in reduced structural integrity of the frame and adjacent lap joint. This reduced structural integrity can increase loading in the fuselage skin, which will accelerate skin crack growth and result in decompression of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2008-13-12, we have determined that we inadvertently omitted paragraph (j)(3) from that AD. Paragraph (j)(3) provided operators with a third option for doing an optional terminating action, which terminates the repetitive inspections required by paragraph (f) of the existing AD.

FAA's Determination and Requirements of This AD

The unsafe condition described previously is likely to exist or develop on other airplanes of the same type design. For this reason, we are issuing this AD to revise AD 2008-13-12. This new AD retains the requirements of the existing AD. This AD also adds an optional terminating action inadvertently omitted from the existing AD.

Costs of Compliance

There are about 1,509 airplanes of the affected design in the worldwide fleet. This AD continues to affect about 524 airplanes of U.S. registry. The inspections currently required by AD 2008-13-12 and retained in this AD take between 18 and 38 work hours per airplane, depending on airplane configuration. The average labor rate is $80 per work hour. Based on these figures, the estimated cost of the currently required inspections required by this AD for U.S. operators is between $754,560 and $1,592,960, or $1,440 and $3,040 per airplane, per inspection cycle.

FAA's Justification and Determination of the Effective Date

The omitted paragraph was previously published in the NPRM for the existing AD and affected operators had the opportunity to comment on that action at that time. Therefore, we have determined that notice and opportunity for public comment before issuing this AD are unnecessary 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-2008-15719; Directorate Identifier 2008-NM-128-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

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 the regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the 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.

§ 39.13

[Amended]

2. The Federal Aviation Administration (FAA) amends § 39.13 by removing amendment 39-15575 ( 73 FR 38905, July 8, 2008) and adding the following new airworthiness directive (AD):

2008-13-12 R1 Boeing: Amendment 39-15719. Docket No. FAA-2008-1147; Directorate Identifier 2008-NM-128-AD.

Effective Date

(a) This AD becomes effective December 1, 2008.

Affected ADs

(b) This AD revises AD 2008-13-12.

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 Alert Service Bulletin 737-53A1261, dated January 19, 2006.

Unsafe Condition

(d) This AD results from a report that the upper frame of the fuselage was severed between stringers S-13L and S-14L at station 747, and the adjacent frame at station 767 had a 1.3-inch-long crack at the same stringer location. We are issuing this AD to detect and correct fatigue cracking of the upper frame to side frame splice of the fuselage, which could result in reduced structural integrity of the frame and adjacent lap joint. This reduced structural integrity can increase loading in the fuselage skin, which will accelerate skin crack growth and result in decompression of the airplane.

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.

Restatement of Requirements of AD 2008-13-12

Repetitive Inspections/Corrective Actions

(f) At the applicable compliance time listed in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 737-53A1261, including Appendices A through X inclusive, dated January 19, 2006; except as provided by paragraph (g) of this AD: Do the applicable inspections for cracking of the upper frame to side frame splice of the fuselage by doing all of the actions, as specified in the Accomplishment Instructions of the service bulletin; except as provided by paragraphs (h) and (i) of this AD. Do all applicable specified and corrective actions before further flight in accordance with the service bulletin. Repeat the applicable inspections thereafter at intervals not to exceed 6,000 flight cycles until the terminating action in paragraph (j) of this AD has been accomplished.

(g) Where Boeing Alert Service Bulletin 737-53A1261, including Appendices A through X inclusive, dated January 19, 2006, specifies a compliance time relative to the date on the service bulletin, this AD requires compliance within the specified compliance time after August 12, 2008 (the effective date of AD 2008-13-12).

(h) If any crack is found during any inspection required by this AD, and Boeing Alert Service Bulletin 737-53A1261, including Appendices A through X inclusive, dated January 19, 2006, specifies to contact Boeing for appropriate action: Before further flight, repair the crack in accordance with the procedures specified in paragraph (k) of this AD.

(i) For airplanes on which a repair has been previously accomplished: If, during accomplishment of the corrective actions required by paragraph (f) of this AD, it is found that the repair was not done per the Boeing 737-100/200 Structural Repair Manual (SRM) 53-10-4, Figure 1; or the Boeing 737-300/400/500 SRM 53-00-07, Figure 201, Repair 1; as applicable; before further flight, repair in accordance with the procedures specified in paragraph (k) of this AD.

Optional Terminating Action

(j) Accomplishing the actions specified in paragraph (j)(1), (j)(2), or (j)(3) of this AD, as applicable, terminates the repetitive inspections required by paragraph (f) of this AD for the repaired or modified frames only.

(1) Accomplishment of the repair specified in Part 3, or the preventive modification specified in Part 4, of the Accomplishment Instructions of Boeing Alert Service Bulletin 737-53A1261, including Appendices A through X inclusive, dated January 19, 2006.

(2) Accomplishment of the repair or the preventive modification specified in Boeing Message M-7200-02-01294, dated August 20, 2002.

(3) Accomplishment of the repair or the preventive modification in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO).

Alternative Methods of Compliance (AMOCs)

(k)(1) The Manager, Seattle ACO, FAA, ATTN: 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]; has the authority to approve AMOCs for this AD, if requested using 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 Alert Service Bulletin 737-53A1261, dated January 19, 2006, to do the actions required by this AD, unless the AD specifies otherwise. If you do the optional terminating actions specified in this AD, you must use Boeing Message M-7200-02-01294, dated August 20, 2002; or Boeing Alert Service Bulletin 737-53A1261, dated January 19, 2006; to do those optional actions, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of Boeing Message M-7200-02-01294, dated August 20, 2002, under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) On August 12, 2008 (73 FR 38905, July 8, 2008), the Director of the Federal Register approved the incorporation by reference of Boeing Alert Service Bulletin 737-53A1261, dated January 19, 2006.

(3) For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207; telephone [phone]; fax [phone]; e-mail [e-mail]; Internet https://www.myboeingfleet.com.

(4) 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 October 10, 2008.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.