03-31444. Airworthiness Directives; Boeing Model 777 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 777 series airplanes. This proposal would require an inspection to determine the part number of the filter/regulator on the fire extinguishing system installed in the lower cargo compartment of the airplane, and replacement of the filter/regulator with a new filter/regulator, if necessary. This action is necessary to prevent leakage of fire extinguishing agent through the filter/regulator of the cargo fire extinguishing system, which could result in the inability of the fire extinguishing system to suppress a fire in the cargo compartment of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by February 5, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-350-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-350-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:

Marcia G. Smith, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington; telephone [phone]; fax [phone].

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 2002-NM-350-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. 2002-NM-350-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report indicating that, during a certification flight test on a Boeing Model 777-300 series airplane, the Halon 1301 fire extinguishing agent flowed through the metered portion of the cargo fire extinguishing system in less than the predicted time. When the cargo fire extinguishing system was checked for leakage, it was determined that the filter/regulator was the source of the leakage. Further investigation found that the original design called for an inadequate heat treatment of the filter/regulator housing which, during production, resulted in an out-of-tolerance O-ring seat. This out-of-tolerance condition could cause the filter/regulator to leak and to fall out of calibration during operation.

Leakage of fire extinguishing agent through the filter/regulator of the cargo fire extinguishing system, if not corrected, could result in the inability of the fire extinguishing system to suppress a fire in the cargo compartment of the airplane.

The cargo fire extinguishing system on certain Model 777-200 series airplanes are identical to those on the affected 777-300 series airplanes. Therefore, both of these models may be subject to the same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Service Bulletin 777-26-0028, dated November 2, 2000, which contains procedures for replacing the filter/regulator with a new filter/regulator. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Boeing Service Bulletin 777-26-0028 also refers to the following Water Kidde Service Bulletins as additional sources of service information for accomplishment of the proposed replacement: 473494-26-405, Revision 1, dated November 1, 2000; 473494-26-422, dated April 13, 2000; 473857-26-406, Revision 1, dated November 1, 2000; 473857-1-26-423, dated April 13, 2000; 473995-1-26-424, dated April 13, 2000; and 473995-26-408, Revision 2, dated November 1, 2000.

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 Rule and Service Bulletin

Although the service bulletin does not require an inspection to determine the part number of the filter/regulator on the fire extinguishing system installed in the cargo compartment, the proposed AD would require such an inspection so that operators can determine if it is necessary to replace the filter/regulator.

Operators should note that, although the service bulletin does not recommend a compliance time for the proposed inspection and replacement, if necessary, the FAA has determined that an interval of within 60 months after the effective date of this AD addresses the unsafe condition in a timely manner. In developing an appropriate compliance time for this proposed AD, the FAA considered the degree of urgency associated with addressing the subject unsafe condition, the average utilization of the affected fleet, and the time necessary to perform the inspection and replacement, if necessary (two hours). In light of all of these factors, the FAA finds a 60-month compliance time for completing the required actions to be warranted, in that it represents an appropriate interval of time allowable for affected airplanes to continue to operate without compromising safety.

Operators should also note that the service bulletin assumes that the actions described in Boeing Service Bulletin 777-26-0020, dated May 13, 1999; and in Boeing Service Bulletin 777-26-0024, dated May 13, 1999; have been accomplished previously, or will be accomplished concurrently with the replacement required by the proposed AD. However, this AD does not mandate that those actions be accomplished before or concurrent with the requirements of this proposed AD. These two service bulletins give instructions for an optional upgrade of the lower cargo compartment's fire suppression system capability to 240 minutes. The airplane operators requested instructions for this optional upgrade, and the manufacturer provided the instructions to them through the service bulletins. All affected airplanes, whether they incorporate the optional upgrade or not, are still required to comply with the requirements of this proposed AD.

Cost Impact

There are approximately 289 airplanes of the affected design in the worldwide fleet. The FAA estimates that 83 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $5,395, or $65 per airplane.

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 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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Boeing: Docket 2002-NM-350-AD.

Applicability: Model 777-200 and 777-300 series airplanes, line numbers 002 through 290 inclusive; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent leakage of fire extinguishing agent through the filter/regulator of the cargo fire extinguishing system, which could result in the inability of the fire extinguishing system to suppress a fire in the cargo compartment of the airplane, accomplish the following:

Note 1:

The Accomplishment Instructions of Boeing Service Bulletin 777-26-0028, dated November 2, 2000, also refer to the following Water Kidde Service Bulletins as additional sources of service information for accomplishment of the replacement: 473494-26-405, Revision 1, dated November 1, 2000; 473494-26-422, dated April 13, 2000; 473857-26-406, Revision 1, dated November 1, 2000; 473857-1-26-423, dated April 13, 2000; 473995-1-26-424, dated April 13, 2000; and 473995-26-408, Revision 2, dated November 1, 2000.

Inspection and Replacement, If Necessary

(a) Within 60 months after the effective date of this AD: Inspect the lower cargo fire extinguishing filter/regulator to determine the part number (P/N). Instead of inspecting the part, a review of airplane maintenance records is acceptable if the P/N of the part can be positively determined from that review.

(1) If no filter regulator P/N 473494-1 (with or without a suffix A), P/N 473857-1 (with or without a suffix A), or P/N 473995-1 (with or without a suffix A) is found, no further action is required by this paragraph.

(2) If any filter/regulator having P/N 473494-1 (with or without a suffix A), P/N 473857-1 (with or without a suffix A), or P/N 473995-1 (with or without a suffix A) is found, within 60 months after the effective date of this AD, replace the filter/regulator with a new filter/regulator, per the Accomplishment Instructions of Boeing Service Bulletin 777-26-0028, dated November 2, 2000.

Parts Installation

(b) As of the effective date of this AD, no person may install on any airplane a filter/regulator with any of the following Walter Kidde Aerospace P/Ns: P/N 473494-1 (with or without a suffix A), P/N 473857-1 (with or without a suffix A), or P/N 473995-1 (with or without a suffix A).

Alternative Methods of Compliance

(c) In accordance with 14 CFR 39.19, the Manager, Seattle Aircraft Certification Office (ACO), FAA, is authorized to approve alternative methods of compliance for this AD.

Issued in Renton, Washington, on December 12, 2003.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.