Airworthiness Directives; Boeing Model 777 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule.

SUMMARY:

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777 series airplanes. This action requires 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 re-identification of the filter/regulator, or 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:

Effective October 7, 2004.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of October 7, 2004.

ADDRESSES:

The service information referenced in this AD may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 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.

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 98055-4056; telephone (425) 917-6484; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Boeing Model 777 series airplanes was published in the Federal Register on December 22, 2003 (68 FR 71049). That action proposed to 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.

Comments

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Support for Notice of Proposed Rulemaking (NPRM)

One commenter supports the NPRM.

Request To Clarify Discussion Section

One commenter requests that we clarify the “Discussion” section of the NPRM. The commenter requests that we change the last sentence in the first paragraph of the “Discussion” section to say, “This out-of-tolerance condition could cause the filter/regulator to leak,” rather than, “This out-of-tolerance condition could cause the filter/regulator to leak and to fall out of calibration during operation.” The commenter states that the calibration and leakage conditions are different issues. The commenter also requests that we clarify the explanation of the problem in the “Discussion” section. The commenter indicates that the leakage due to a problem with an O-ring seat is different from the calibration issue, which was caused by a loose locknut.

We agree with the commenter's statements, but cannot make changes to the “Discussion” section itself because that section is not restated in the final rule. However, for clarity's sake and for operators' reference, have rewritten portions of the paragraph to respond to the comment. The changed paragraph is as follows:

“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. The manufacturer discovered that several housing assemblies had a warped O-ring groove at the point where the filter element retainer was screwed into the housing. The warping was caused by heat treatment of the housing with a finished O-ring groove. Furthermore, during qualification testing of a different filter/regulator assembly, the unit failed the flow test after the vibration testing. It was discovered that the locknut in the variable pressure regulator had loosened during vibration testing, allowing the regulator adjustment screw assembly to move. This caused a slight change in the unit's flow rate.”

Request To Exempt/Re-Identify Certain Part Numbers

Two commenters observed that filter/regulators with parts that have a serial number with suffix “A” are not subject to the 60-month replacement requirement of the proposed rule. One commenter, the parts manufacturer, states that parts with a suffix “A” in the serial number are identical in form, fit, and function to parts with part numbers (P/N) that end with a “-3” and that parts with P/Ns that end with a “-3” are not subject to the requirements of the proposed rule. The other commenter notes that Walter Kidde Service Bulletin 473494-26-405 allows parts with a suffix “A” in the serial number to remain in service until schedule maintenance is required.

We partially agree with the commenters' requests. We have changed the final rule to exclude the requirement to replace filter/regulators having a suffix “A” in the serial number. However, although one of the commenters states that the applicable Walter Kidde service bulletin allows parts having a suffix “A” to remain in service, the same bulletin still requires re-identification of the part. Therefore, we have changed the final rule to allow the option of replacing or reidentifying filter/regulators having a suffix “A” in the serial number, in accordance with the procedures in the applicable Walter Kidde service bulletin. We have revised paragraph (a) and paragraph (b) of the final rule accordingly.

Request for Editorial Change

The same commenter requests that we change two references to Walter Kidde service bulletins, which we inadvertently spelled “Water” Kidde. One of the references is in Note 1 of the NPRM, and the other is in the section titled “Explanation of Relevant Service Information.”

We agree with the commenter's request. However, we have made a change only to Note 1 in the final rule because the section titled “Explanation of Relevant Service Information” is not restated in the final rule.

Conclusion

After careful review of the available data, including the comments noted above, we have determined that air safety and the public interest require the adoption of the rule with the changes previously described. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Explanation of Editorial Change to Proposed AD

We have changed all references to filter/regulator that have P/Ns “with a suffix A,” to P/Ns that have a serial number with suffix A. We have determined that this change shows that the suffix number is part of the serial number rather than part of the P/N.

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 will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the 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 requirements of this AD action, and that no operator would accomplish those actions in the future if this 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 adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this action (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. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

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

2004-17-05 Boeing: Amendment 39-13777. 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 Walter 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, P/N 473857-1, or P/N 473995-1 is found, no further action is required by this paragraph.

(2) If any filter/regulator having P/N 473494-1, P/N 473857-1, or P/N 473995-1 is found and the serial number does not contain suffix “A,” 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.

(3) If any filter/regulator having P/N 473494-1, P/N 473857-1, or P/N 473995-1 containing a serial number with suffix “A” is found, within 60 months after the effective date of this AD, do paragraph (a)(3)(i) or (a)(3)(ii).

(i) Re-identify the filter/regulator by following the Accomplishment Instructions of the applicable Walter Kidde Service Bulletin that follows: for P/N 473494-1, use Service Bulletin 473494-26-422, dated April 13, 2000; for P/N 473857-1, use Service Bulletin 473857-1-26-423, dated April 13, 2000; for P/N 473995-1, use Service Bulletin 473995-1-26-424, dated April 13, 2000.

(ii) Replace the filter/regulator with a new filter regulator per the Accomplishment Instructions of Boeing Service Bulletin 777-26-0028, dated November 2, 2000.

Note 2:

Filter/regulators having P/N 473494-1, P/N 473857-1, and P/N 473995-1 that have a serial number with suffix “A” are good parts and are identical in form, fit, and function to P/N 473494-3, P/N 473857-3, and P/N 473995-3 respectively. Re-identification of the part numbers ensures unique part numbering.

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 serial number with suffix “A”), P/N 473857-1 (with or without a serial number with suffix “A”), or P/N 473995-1 (with or without a serial number with suffix “A”), unless a P/N with a serial number with suffix “A” has been re-identified per paragraph (a)(3)(i) of this AD.

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 (AMOCs) for this AD.

Incorporation by Reference

(d) Unless otherwise specified in this AD, the actions shall be done in accordance with the service bulletins listed in Table 1 of this AD.

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207; and Kidde Technologies, Inc., 4200 Airport Drive Northwest, Wilson, North Carolina 27896. Copies may be inspected 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.

Effective Date

(e) This amendment becomes effective on October 7, 2004.