E7-24337. Airworthiness Directives; Boeing Model 757-200, -200CB, and -300 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Final rule.

SUMMARY:

We are adopting a new airworthiness directive (AD) for certain Boeing Model 757-200, -200CB, and -300 series airplanes. This AD requires repetitive detailed inspections with a borescope for cracks of the intercostal tee clips; or repetitive detailed inspections for cracks of the intercostal tee clips and attachment fasteners at the number 3 and number 4 doorstops of the passenger door cutouts; and related investigative and corrective actions if necessary. This AD also provides an optional terminating action for the repetitive inspections. This AD results from reports of cracked intercostal tee clips at the number 3 and number 4 doorstops of the passenger door cutouts. We are issuing this AD to detect and correct cracking of the tee clips, which could result in additional stress on the adjacent tee clips, surrounding intercostals, edge frame, door structure and doorstops. This additional stress could cause further cracking or breaking of the tee clips, which could result in failure of the door to seal and consequent rapid decompression of the airplane.

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.

We must receive comments on this AD by 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 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:

Jason Deutschman, 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 757-200, -200CB, and -300 series airplanes. That NPRM was published in the Federal Register on August 16, 2007 (72 FR 45961). That NPRM proposed to require repetitive inspections for cracks of the intercostal tee clips and attachment fasteners at the number 3 and number 4 doorstops of the passenger door cutouts, or repetitive inspections for cracks of the intercostal tee clips; and related investigative/corrective actions if necessary. That NPRM also provides an optional terminating action for the repetitive inspections.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received.

Support for the NPRM

Continental Airlines (CAL) supports the NPRM and notes that it has an on-going customized passenger door maintenance program already in place to inspect the subject area on its airplanes at 4C and 8C heavy checks. CAL adds that it has found no cracks on its airplanes, but intends to incorporate the terminating action provided in the NPRM at the next 4C or 8C opportunity.

Request To Include Access and Close-up Costs

Boeing asks that the costs to gain and close access for the proposed detailed inspection be included to better reflect the cost difference between the two inspection options provided in the NPRM (detailed versus borescope). Boeing estimates 9.5 work hours to gain access by removing existing galleys, and Boeing estimates another 10 work hours to replace the galleys after inspection to close access. Boeing states that this adds a total of 19.5 hours of work at a cost of $1,560 per airplane based on an average labor rate of $80 per work hour. This adds up to an additional cost to the fleet of $505,440 over the $51,840 cost that is shown. This access cost is not incurred if the alternative borescope inspection method is used; however, if repairs are to be performed, either to address cracking or to terminate inspections, the access and close-out costs would be incurred in addition to parts costs in order to perform the required part replacements. Boeing adds that this would affect the supplementary information in the estimated Costs of Compliance paragraph.

We acknowledge Boeing's concerns. However, because operators are given the option of doing the detailed inspection or the detailed inspection with a borescope (which takes longer), the cost depends on which inspection is done. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, or the costs of “on-condition” actions such as repairs (that is, actions needed to correct an unsafe condition). We have made no change to the AD in this regard.

Clarification of Summary Language

We revised the Summary section of this final rule to specify the repetitive inspection methods.

Conclusion

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

Difference Between the Proposed AD and Service Information

The service bulletin specifies to contact the manufacturer for instructions on how to repair certain conditions, but this AD requires repairing those conditions in one of the following ways:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Costs of Compliance

There are about 912 airplanes of the affected design in the worldwide fleet. This AD affects about 324 airplanes of U.S. registry.

The detailed inspection, if accomplished, takes about 2 work hours per airplane, at an average work rate of $80 per work hour. Based on these figures, the estimated cost of the detailed inspections required by this AD is $51,840, or $160 per airplane, per inspection cycle.

The borescope inspection, if accomplished, takes about 3 work hours per airplane, at an average work rate of $80 per work hour. Based on these figures, the estimated cost of the borescope inspections required by this AD is $77,760, or $240 per airplane, per inspection cycle.

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:

2007-26-02 Boeing: Amendment 39-15304. Docket No. FAA-2007-28990; Directorate Identifier 2007-NM-033-AD.

Effective Date

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

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 757-200, -200CB, and -300 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006.

Unsafe Condition

(d) This AD results from reports of cracked intercostal tee clips at the number 3 and number 4 doorstops of the passenger door cutouts. We are issuing this AD to detect and correct cracking of the tee clips, which could result in additional stress on the adjacent tee clips, surrounding intercostals, edge frame, door structure and doorstops. This additional stress could cause further cracking or breaking of the tee clips, which could result in failure of the door to seal and consequent rapid 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.

Repetitive Inspections/Investigative and Corrective Actions

(f) Before the accumulation of 20,000 total flight cycles or within 3,000 flight cycles after the effective date of this AD, whichever is later: Do the applicable inspection specified in paragraph (f)(1) or (f)(2) of this AD by doing all the actions including all applicable related investigative (additional detailed inspections if necessary) and corrective actions; except as provided by paragraph (g) of this AD; in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006. All related investigative and corrective actions must be done before further flight.

(1) Do a detailed inspection for cracks of the intercostal tee clips and attachment fasteners at the number 3 and number 4 doorstops of the passenger door cutouts. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles until accomplishment of the terminating action specified in paragraph (h) of this AD.

(2) Do a detailed inspection with a borescope for cracks of the intercostal tee clips. Repeat the inspection thereafter at intervals not to exceed 3,000 flight cycles until accomplishment of the terminating action specified in paragraph (h) of this AD.

(g) If any cracked structure is found during any inspection required by this AD, and the Accomplishment Instructions of Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006, specify to contact Boeing for appropriate action: Before further flight, repair any cracked structure using a method approved in accordance with the procedures specified in paragraph (i)(2) of this AD.

Optional Terminating Action

(h) Replacing both intercostal tee clips on the left and right sides with new tee clips in accordance with Part 3 of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-53A0093, dated November 8, 2006, terminates the repetitive inspections required by this AD.

Alternative Methods of Compliance (AMOCs)

(i)(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) 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.

(3) 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.

Material Incorporated by Reference

(j) You must use Boeing Alert Service Bulletin 757-53A0093, dated November 8, 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.