Airworthiness Directives; Boeing Model 727, 727-100C, 727-200F, and 727C Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 727, 727-100C, 727-200F, and 727C series airplanes. This proposal would require repetitive open-hole high frequency eddy current inspections for cracks in the fuselage skin, strap (bearstrap), and doubler at the forward and aft hinge fittings for the main deck cargo door, and repair of any cracks found. This action is necessary to detect and correct such cracks, which could reach critical crack length and result in rapid decompression of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by January 20, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-191-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2003-NM-191-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6437; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2003-NM-191-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2003-NM-191-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received reports of multiple fatigue cracks in the fuselage skin, strap (bearstrap), and doubler at the forward and aft hinge fittings for the main cargo door on six airplanes. The cracks have been up to 0.15 inch long and have originated from the fastener holes common to the forward and aft main cargo door hinge fittings. The cracks have been found on airplanes with between 45,000 and 66,300 flight hours, and between 34,000 and 50,000 flight cycles. The cracks were discovered during the accomplishment of the inspections specified in the Supplemental Structural Inspection Document. Such cracking, if not corrected, could reach critical crack length and result in rapid decompression of the airplane.

Explanation of Relevant Service Information

We have reviewed and approved Boeing Alert Service Bulletin 727-53A0226, dated September 11, 2003, which describes procedures for repetitive open-hole high frequency eddy current inspections for cracks in the fuselage skin, strap (bearstrap), and doubler at the forward and aft hinge fittings for the main deck cargo door. These inspections are recommended on airplanes before they have accumulated 30,000 total flight cycles, or within 1,500 flight cycles (or 3,000 flight cycles for freighters) after the effective date of the AD, whichever occurs later, and are repeated at intervals not to exceed 10,000 flight cycles. The fittings are located at body stations 486 and 610 and at stringer 3L. The service bulletin recommends that operators contact Boeing for repair instructions.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.

Differences Between Proposed AD and Service Bulletin

The service bulletin specifies compliance times relative to the date of the service bulletin; however, this proposed AD would require compliance with the thresholds after the effective date of the AD.

Although the service bulletin specifies that operators may contact the manufacturer for disposition of certain repair conditions, this proposed AD would require operators to repair those conditions per a method approved by the Manager of the Seattle Aircraft Certification Office of the FAA, or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the FAA to make such findings.

This proposed AD would also require that, within 12 months following a repair, operators implement an inspection program for the repair into the 727 maintenance program in accordance with a method and compliance times approved by the Manager, Seattle ACO; or per data meeting 14 CFR 25.571 (Amendment 25-54 or later) approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings. To ensure timely detection of cracking in those areas, we have determined that new inspection methods and compliance times are necessary for areas that have been repaired. The new inspection methods and compliance times should meet the requirements of 14 CFR 25.571 (Amendment 25-54 or later).

Interim Action

We consider this proposed AD interim action. If final action is later identified, we may consider further rulemaking then.

Cost Impact

There are approximately 195 airplanes of the affected design in the worldwide fleet. We estimate that 133 airplanes of U.S. registry would be affected by this proposed AD. We provide the following cost estimates to comply with this proposed AD, per inspection cycle:

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. 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, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein would 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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.