05-16455. Airworthiness Directives; Boeing Model 747, 757, 767 and 777 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Final rule.

SUMMARY:

The FAA is superseding an existing airworthiness directive (AD), which applies to certain Boeing Model 747, 757, 767, and 777 series airplanes. That AD currently requires modifying certain drip shields located on the flight deck, and follow-on actions. This new AD removes certain airplanes that are included in the applicability statement of the existing AD, and requires modifying additional drip shields on the flight deck of certain other airplanes. This AD is prompted by a determination that certain airplanes have drip shields that are not adequately resistant to fire. We are issuing this AD to prevent potential ignition of the moisture barrier cover of the drip shield, which could propagate a small fire that results from an electrical arc, leading to a larger fire.

DATES:

This AD becomes effective September 27, 2005.

The incorporation by reference of certain publications listed in the AD is approved by the Director of the Federal Register as of September 27, 2005.

On February 2, 2001 (65 FR 82901, December 29, 2000), the Director of the Federal Register approved the incorporation by reference of certain other publications listed in the AD.

ADDRESSES:

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Docket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Washington, DC. This docket number is FAA-2004-19865; the directorate identifier for this docket is 2003-NM-242-AD.

FOR FURTHER INFORMATION CONTACT:

Patrick Gillespie, Aerospace Engineer, Cabin Safety and Environmental Systems Branch, ANM-150S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA proposed to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) with an AD to supersede AD 2000-26-04, amendment 39-12054 (65 FR 82901, December 29, 2000). The existing AD applies to certain Boeing Model 747, 757, 767, and 777 series airplanes. The proposed AD was published in the Federal Register on December 16, 2004 (69 FR 75267), to require modifying certain drip shields located on the flight deck, and follow-on actions.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD.

Support for the Proposed AD

One commenter concurs with the contents of the proposed AD and has no additional comments.

Request To Revise Applicability Statement

One commenter, the airplane manufacturer, requests that we revise Table 1 under Applicability in the proposed AD to remove the Model 777 series airplane having line number (L/N) 254. The commenter states that the affected Model 777 L/Ns include line numbers prior to 254, except L/Ns 1, 120, 219, 230, 235, 242, 245, and 249.

We agree and have revised Table 1 of this AD to remove L/N 254.

Request To Add Later Service Bulletin Revision

One commenter requests that we revise paragraph (f) of the proposed AD to refer to Boeing Service Bulletin 757-25-0228, Revision 1, dated March 28, 2002 (for Model 757-300 series airplanes); and Boeing Service Bulletin 777-25-0164, Revision 1, including Appendices A, B, C, and D, all dated March 22, 2001; as acceptable methods of compliance with that paragraph. The commenter notes that the procedures in Revision 1 of these service bulletins are substantially similar to those in the original issues of the service bulletin, which paragraph (f) refers to as acceptable sources of service information for Model 757-300 and Model 777 series airplanes. Boeing Service Bulletin 757-25-0228, Revision 1, clarifies certain procedures and corrects a part number for a washer used to attach fire blocks. Boeing Service Bulletin 777-25-0164, Revision 1, provides additional installation instructions and placard and dimensional information. The commenter also notes that the effectivity listing is the same in Revision 1 of the service bulletins as in the original issues.

We agree. We note that Revision 1 of these service bulletins was approved as an alternative method of compliance (AMOC) for AD 2000-26-04, and that AMOC remains valid as specified in paragraph (k)(2) of this AD. However, for clarification and for the convenience of affected operators, we have also revised paragraph (f) of this AD to specify both the original issue and Revision 1 of these service bulletins as acceptable methods of compliance for doing the modification required by that paragraph.

Request To Clarify Requirements for Certain Model 757 Series Airplanes

One commenter requests that we revise the proposed AD to allow the proposed actions to be accomplished in accordance with previous revisions of Boeing Service Bulletin 757-25-0226 for Boeing Model 757 series airplanes identified in Groups 2 and 4 of Boeing Service Bulletin 757-25-0226, Revision 3, dated September 2, 2004. The commenter states that, for airplanes in those groups, Boeing Service Bulletins 757-25-0226, Revision 2, dated October 31, 2002, and Revision 3, do not add additional work beyond what is specified for those airplanes in the original issue, dated July 3, 2000, and Revision 1, dated February 15, 2001. The commenter states that we should make it clear that no additional work is required by this AD for any airplane in Group 2 or 4 that was modified in accordance with a previous issue of the service bulletin. The commenter adds that the proposed AD should also be revised to give credit for using any revision of Boeing Service Bulletin 757-25-0226 to modify any airplane in Group 2 or 4. The commenter also notes that an AMOC was issued for AD 2000-26-04 to allow certain required actions to be accomplished in accordance with Boeing Service Bulletin 757-25-0226, Revision 1. The commenter states that this AMOC should also still be valid for airplanes in Groups 2 and 4.

We agree with the commenter's requests for the reasons stated by the commenter, and accordingly have made the following changes to this AD:

• We revised paragraph (i) of this AD to specify that paragraph (i) applies only to airplanes identified as being in Group 1 or 3 by Boeing Service Bulletin 757-25-0226, Revision 3.
• We revised paragraph (f) to state that only airplanes in Group 1 or 3 are required to use Revision 3 after the effective date of this AD.
• We added a new paragraph (j)(2) to this AD (and renumbered a subsequent paragraph) to give credit for modifying the drip shields on airplanes in Groups 2 and 4 before the effective date of this AD in accordance with Revision 1 of Boeing Service Bulletin 757-25-0226. (Paragraph (j)(1) of this AD already gives credit for modifying the drip shields in accordance with Revision 2 of that service bulletin.)
• We revised paragraph (k)(2) of this AD to state that, except for Model 757-200, -200CB, and -200PF series airplanes listed in Groups 1 and 3 of Boeing Service Bulletin 757-25-0226, Revision 3, dated September 2, 2004, AMOCs approved previously in accordance with AD 2000-26-04, amendment 39-12054, are acceptable for compliance with this AD.
• We revised the Costs of Compliance section to reduce the estimated number of Model 757-200, -200CB, and -200PF series airplanes subject to the new requirements from 491 U.S.-registered airplanes to 350. This figure includes only the airplanes in Groups 1 and 3.

Request To Revise Estimated Number of Airplanes No Longer Affected

One commenter, the airplane manufacturer, states that the estimate of Model 747 series airplanes no longer affected, as stated in the Actions Since Existing AD Was Issued section of the proposed AD, should be increased from 550 to 650 airplanes. The commenter points out that the effectivity listing of the original issue of Boeing Service Bulletin 747-25-3253, dated June 29, 2000, included L/Ns 1 through 1234 inclusive, except 1174 and 1216 (approximately 1230 airplanes). However, the effectivity listing of Boeing Service Bulletin 747-25-3253, Revision 3, dated September 4, 2003, includes L/Ns 1 through 299 inclusive and 951 through 1234 inclusive, except 292, 296, 297, 1174, and 1216 (approximately 580 airplanes). Therefore, approximately 650 airplanes are no longer affected.

We agree with the intent of the commenter's request. However, the relevant paragraph to which the commenter refers is not restated in this final rule. Thus, we have made no change in this regard.

Request To Increase Estimate for Costs of Compliance

One commenter requests that we increase the number of work hours necessary to accomplish the required actions on affected Model 757 series airplanes. The commenter notes that the proposed AD estimates that 26 work hours would be needed, while the referenced service bulletin for Model 757 series airplanes states total work-hour estimates of 107, 94.5, 74, and 66 work hours for airplanes in Groups 1, 2, 3, and 4, respectively. The commenter states that its experience indicates that the figures provided by Boeing in the service bulletin are accurate, but the FAA's estimate times are lower than the service bulletin figures and, as a result, contribute to an erroneously low cost estimate.

We partially agree with the commenter's request. We note that the total work hour estimates to which the commenter refers include time for gaining access and closing up. The cost analysis in AD actions, however, typically does not include costs such as the time required to gain access and close up, time necessary for planning, or time necessitated by other administrative actions. Costs for those type of actions may vary significantly among operators and are almost impossible to calculate.

However, we do agree that the costs of compliance estimated in the proposed AD for Model 757 series airplanes did not include the work hours necessary for testing, as specified in Boeing Service Bulletin 757-25-0226, Revision 3. Therefore, we have revised the estimated costs of compliance in this AD to estimate that 58 work hours are needed to do the required actions on each affected Model 757 series airplane.

Conclusion

We have carefully reviewed the available data, including the comments that have been submitted, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

There are about 2,222 airplanes of affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with the actions that are required by AD 2000-26-04 and retained in this proposed AD. The average labor rate is $65 per work hour.

Estimated Costs

Model	U.S.- registered airplanes	Work hours (estimated)	Labor cost (estimated)	Parts cost (estimated)	Maximum fleet cost (estimated)
747	105	39	$2,535	$2,300 to 3,500	$633,675
757	491	58	3,770	1,700	2,685,770
767	140	17	1,105	2,300	476,700
777	56	3	195	1,700	106,120

For Model 747 series airplanes listed in Group 1 in Boeing Service Bulletin 747-25-3253, Revision 3, in lieu of doing the modification of the drip shields, this proposed AD provides an option to take samples of the drip shields to determine if the modification is necessary. Therefore, the estimated costs above may be reduced if some airplanes do not need the modification. It would take approximately 18 work hours to do the sampling, at an average labor rate of $65 per work hour. Based on these figures, the cost impact of the sampling is estimated to be $1,170 per sampled airplane.

As many as 350 U.S.-registered Model 757-200, -200CB, and -200PF series airplanes may be subject to the new proposed actions. These new actions would take about 8 additional work hours per airplane, at an average labor rate of $65 per work hour. Required parts would cost an additional $160 per airplane (for a total parts cost of $1,860 per airplane). Based on these figures, the estimated cost of the new actions specified in this proposed AD for U.S. operators of affected airplanes is up to an additional $238,000, or $680 per airplane.

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

We have determined that 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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 removing amendment 39-12054 ( 65 FR 82901, December 29, 2000), and by adding the following new airworthiness directive (AD):

2005-17-09 Boeing: Amendment 39-14230. Docket No. FAA-2004-19865; Directorate Identifier 2003-NM-242-AD.

Effective Date

(a) This AD becomes effective September 27, 2005.

Affected ADs

(b) This AD supersedes AD 2000-26-04, amendment 39-12054.

Applicability

(c) This AD applies to Model 747, 757, 767, and 777 series airplanes having the line numbers (L/Ns) listed in Table 1 of this AD; certificated in any category.

Table 1.—Applicability

Model	Affected L/Ns	Except L/Ns
747	1 through 299 inclusive and 951 through 1234 inclusive	292, 296, 297, 1174, 1216.
757	2 through 895 inclusive	870, 886, 894.
767	470 through 768 inclusive	758.
777	2 through 253 inclusive	120, 219, 230, 235, 242, 245, 249.

Unsafe Condition

(d) This AD was prompted by a determination that certain airplanes have drip shields that are not adequately resistant to fire. We are issuing this AD to prevent potential ignition of the moisture barrier cover of the drip shield, which could propagate a small fire that results from an electrical arc, leading to a larger fire.

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.

Requirements of AD 2000-26-04

Modification

(f) Within 6 years after February 2, 2001 (the effective date of AD 2000-26-04), accomplish paragraphs (f)(1), (f)(2), and (f)(3) of this AD; in accordance with Boeing Service Bulletin 747-25-3253, dated June 29, 2000, or Revision 3, dated September 4, 2003; 757-25-0226, dated July 3, 2000, or Revision 3, dated September 2, 2004; 757-25-0228, dated July 3, 2000, or Revision 1, dated March 28, 2002; 767-25-0290, dated June 29, 2000, or Revision 4, dated October 28, 2004; or 777-25-0164, dated June 29, 2000, or Revision 1, including Appendices A, B, C, and D, all dated March 22, 2001; as applicable; except as provided by paragraph (g) of this AD. For Model 757-200, -200CB, and -200PF series airplanes identified as being in Groups 1 and 3 in Boeing Service Bulletin 757-25-0226, Revision 3: As of the effective date of this AD, only Revision 3 of the service bulletin may be used. For Model 747 and 767 series airplanes: As of the effective date of this AD, only Boeing Service Bulletin 747-25-3253, Revision 3, or 767-25-0290, Revision 4, as applicable, may be used.

(1) Modify drip shields located on the flight deck by installing fire blocks.

(2) Prior to further flight following accomplishment of paragraph (f)(1) of this AD, perform a functional test of any system disturbed by the modification, in accordance with the applicable service bulletin or airplane maintenance manual (AMM), as applicable. If any functional test fails, prior to further flight, isolate the fault, correct the discrepancy in accordance with the applicable AMM, and repeat the failed test until it is successfully accomplished.

(3) Prior to further flight following the accomplishment of paragraphs (f)(1) and (f)(2) of this AD, install placards on all modified drip shields.

(g) If any wires or equipment are installed on the outboard surface of the drip shield (that is, between the drip shield and the airplane structure), modify that area in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.

Optional Sampling (Certain Model 747 Series Airplanes)

(h) For Model 747 series airplanes listed in Group 1 in Boeing Service Bulletin 747-25-3253, Revision 3, dated September 4, 2003: In lieu of accomplishing paragraph (f) of this AD, within 6 years after February 2, 2001, collect samples of the insulation and adhesive of the drip shields, and submit the samples to the manufacturer for testing, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 747-25-3253, dated June 29, 2000, or Revision 3, dated September 4, 2003. After the effective date of this AD, only Revision 3 may be used.

(1) If the test on all samples is positive, no further action is required by this AD.

(2) If the test on any sample is negative, accomplish paragraph (f) of this AD before the compliance time specified in that paragraph.

New Requirements of This AD

Model 757-200/-200CB/-200PF Series Airplanes Previously Modified

(i) For Model 757-200, -200CB, and -200PF series airplanes identified as being in Group 1 or 3 in Boeing Service Bulletin 757-25-0226, Revision 3, dated September 2, 2004, and that were modified before the effective date of this AD in accordance with Boeing Service Bulletin 757-25-0226, dated July 3, 2000: Within 72 months after the effective date of this AD, modify drip shields located above windows number 2 and 3 on the flight deck by installing fire blocks, in accordance with the Accomplishment Instructions of Boeing Service Bulletin 757-25-0226, Revision 3, dated September 2, 2004; except as provided by paragraph (g) of this AD. After the modification, do the actions required by paragraphs (f)(2) and (f)(3) of this AD because these actions apply to the drip shields modified in accordance with this paragraph.

Previously Accomplished Actions

(j) Modifying the drip shields before the effective date of this AD in accordance with the applicable service bulletin specified in paragraph (j)(1), (j)(2), or (j)(3) of this AD is acceptable for compliance with the corresponding requirements of paragraphs (f) and (i) of this AD, as applicable.

(1) For Model 757-200, -200CB, and -200PF series airplanes: Boeing Service Bulletin 757-25-0226, Revision 2, dated October 31, 2002.

(2) For Model 757-200, -200CB, and -200PF series airplanes identified in Groups 2 and 4 of Boeing Service Bulletin 757-25-0226, Revision 3, dated September 2, 2004: Boeing Service Bulletin 757-25-0226, Revision 1, dated February 15, 2001.

(3) For Model 767 series airplanes: Boeing Service Bulletin 767-25-0290, Revision 3, dated June 26, 2003.

Alternative Methods of Compliance (AMOCs)

(k)(1) The Manager, Seattle ACO, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(2) Except for Model 757-200, -200CB, and -200PF series airplanes listed in Groups 1 and 3 of Boeing Service Bulletin 757-25-0226, Revision 3, dated September 2, 2004: Alternative methods of compliance, approved previously in accordance with AD 2000-26-04, amendment 39-12054, are approved as alternative methods of compliance with this AD.

Material Incorporated by Reference

(l) You must use the applicable documents listed in Table 2 of this AD to perform the actions that are required by this AD, unless the AD specifies otherwise.

Table 2.—Material Incorporated by Reference

Boeing service bulletin	Revision level	Date
747-25-3253, including Appendices A, B, and C	Original	June 29, 2000.
747-25-3253	3	September 4, 2003.
757-25-0226, including Appendices A, B, and C	Original	July 3, 2000.
757-25-0226	3	September 2, 2004.
757-25-0228, including Appendices A, B, and C	Original	July 3, 2000.
757-25-0228	1	March 28, 2002.
767-25-0290, including Appendices A, B, and C	Original	June 29, 2000.
767-25-0290	4	October 28, 2004.
777-25-0164, including Appendices A, B, and C	Original	June 29, 2000.
777-25-0164, including Appendices A, B, C, and D	1	March 22, 2001.

(1) The Director of the Federal Register approves the incorporation by reference of the documents listed in Table 3 of this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.

Table 3.—New Material Incorporated by Reference

Boeing service bulletin	Revision level	Date
747-25-3253	3	September 4, 2003.
757-25-0226	3	September 2, 2004.
757-25-0228	1	March 28, 2002.
767-25-0290	4	October 28, 2004.
777-25-0164, including Appendices A, B, C, and D	1	March 22, 2001.

(2) On February 2, 2001 (65 FR 82901, December 29, 2000), the Director of the Federal Register approved the incorporation by reference of the documents listed in Table 4 of this AD.

Table 4.—Material Previously Incorporated by Reference

Boeing service bulletin	Revision level	Date
747-25-3253, including Appendices A, B, and C	Original	June 29, 2000.
757-25-0226, including Appendices A, B, and C	Original	July 3, 2000.
757-25-0228, including Appendices A, B, and C	Original	July 3, 2000.
767-25-0290, including Appendices A, B, and C	Original	June 29, 2000.
777-25-0164, including Appendices A, B, and C	Original	June 29, 2000.

(3) To get copies of the service information, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207. To view the AD docket, go to the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC. To review copies of the service information, go to the National Archives and Records Administration (NARA). For information on the availability of this material at the NARA, call [phone], or go to http://www.archives.gov/​federal-register/​cfr/​ibr-locations.html.

Issued in Renton, Washington, on August 11, 2005.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.