Airworthiness Directives; Boeing Model 727-100 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 727-100 series airplanes. This proposal would require repetitive inspections to detect corrosion of the lower surface of the wing center section and the surrounding area, and follow-on actions. This proposal is prompted by reports of corrosion progression through the lower surface of the wing center section into the center wing fuel tank, and subsequent fuel leakage into the ram air duct. The actions specified by the proposed AD are intended to detect and correct such conditions, which, if combined with a leak in the primary or secondary heat exchanger, could result in the release of fuel vapors into the cabin, and consequent adverse effects on flight crew and passengers.

DATES:

Comments must be received by May 22, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-27-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.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Airplane Group, PO 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:

Stan Wood, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2772; fax (425) 227-1181.

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 notice may be changed in light of the comments received.

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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-27-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. 2000-NM-27-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On November 7, 1985, the FAA issued AD 85-24-02, amendment 39-5170 (50 FR 47356, November 18, 1985), applicable to all Boeing Model 727-200 series airplanes, which requires repetitive inspections for corrosion, and repair, as necessary, of the lower surface of the wing center section, which forms the upper wall of the ram air plenum chambers.

Since the issuance of that AD, the manufacturer has notified the FAA that certain airplanes were inadvertently not included in the effectivity listing in Boeing Service Bulletin 727-51-17, dated April 26, 1974, which was referenced as the appropriate source of service information for accomplishment of the actions required by AD 85-24-02. That service bulletin describes corrosion inspections for Model 727-200 series airplanes having integral fuel cells installed. Model 727-100 series airplanes were not included in the effectivity of that service bulletin, and consequently, in the applicability of the existing AD, due to the fact that bladder-type fuel cells are installed on the majority of those airplanes. However, it has now been determined that there are three Model 727-100 series airplanes having integral fuel cells installed that are subject to the same unsafe condition as the airplanes that are included in the applicability statement of AD 85-24-02. Therefore, the FAA finds that additional rulemaking is necessary to ensure that the unsafe condition is addressed on all affected airplanes.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Service Bulletin 727-51-17, Revision 1, dated January 24, 1986, which describes procedures for repetitive inspections to detect corrosion of the lower surface of the wing center section and the surrounding area, and follow-on actions. The follow-on actions consist of the application of corrosion-inhibiting compound and repair of any corrosion. Accomplishment of the actions described in the service bulletin is intended to adequately address the identified unsafe condition.

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.

Difference Between Proposed Rule and Service Bulletin

Operators should note that Revision 1 of the service bulletin (as well as the original issue of the service bulletin, which was referenced as the appropriate source of service information for accomplishment of the actions required by AD 85-24-02), specifies the effectivity of that service bulletin as, “all Model 727-200 series airplanes.” However, the manufacturer has informed the FAA that it has identified three Model 727-100 series airplanes that were inadvertently not included in the effectivity listing and have not accomplished the actions required by that AD. Therefore, the applicability section of this proposed rule specifies only those airplanes (described as Group 1 airplanes in the service bulletin).

Operators also should note that, although the service bulletin specifies that the manufacturer may be contacted for disposition of certain corrosion repair conditions, this proposal would require the repair of those conditions to be accomplished in accordance with a method approved by the FAA.

Cost Impact

There are 3 Model 727-100 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 2 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 12 work hours per airplane to accomplish the proposed inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $1,440, or $720 per airplane, per inspection cycle.

The cost impact figure discussed above is 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 AD were not adopted.

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.