[Federal Register Volume 70, Number 238 (Tuesday, December 13, 2005)]
[Proposed Rules]
[Pages 73663-73665]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23956]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-23282; Directorate Identifier 2005-NM-210-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200 and -300 Series 
Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 757-200 and -300 series airplanes. This 
proposed AD would require installing clamps on certain end caps of the 
overhead distribution ducts, and doing other specified and related 
investigative actions as necessary. This proposed AD results from 
finding that the end caps of the overhead distribution ducts for the 
air conditioning system were not bonded to the ducts with an adhesive. 
We are proposing this AD to detect and correct loosened end caps, which 
could change the air flow balance in the airplane. During a smoke event 
in the cargo or main electronics compartments, the incorrect balance of 
air flow could change the smoke clearance air capacity and result in 
smoke and toxic fumes penetrating the flight deck and main cabin.

DATES: We must receive comments on this proposed AD by January 27, 
2006.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     Fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for the service information identified in this 
proposed AD.

FOR FURTHER INFORMATION CONTACT: Barbara Mudrovich, 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) 917-6477; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

[[Page 73664]]

Comments Invited

    We invite you to submit any relevant written data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed in the ADDRESSES section. Include the docket number ``FAA-2005-
23282; Directorate Identifier 2005-NM-210-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments received by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD.
    Using the search function of that Web site, anyone can find and 
read the comments in any of our dockets, including the name of the 
individual who sent the comment (or signed the comment on behalf of an 
association, business, labor union, etc.). You may review DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

    You may 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 (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the Docket Management System 
receives them.

Discussion

    We have received a report indicating that the airplane manufacturer 
found that the end caps of the overhead distribution ducts of the air 
conditioning system were not bonded to the ducts with an adhesive. The 
parts manufacturer determined from a records check that none of the 
overhead duct assemblies had end caps bonded to the ducts. Instead, the 
overhead duct assemblies had been delivered with plastic tie straps to 
hold the end caps onto the ducts. In some cases, the airplane 
manufacturer's mechanics removed the plastic tie straps from the end 
caps because the tie straps are not specified on the overhead duct 
assembly drawing. The bead on the end of ducts alone will not keep the 
end caps from loosening. A loosened end cap could change the air flow 
balance in the airplane. This condition, if not corrected, could change 
the smoke clearance air capacity during a smoke event in the cargo 
compartment or main electronics compartments and result in smoke and 
toxic fumes penetrating the flight deck and main cabin.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletins 757-21-
0106 (for Model 757-200 series airplanes) and 757-21-0107 (for Model 
757-300 series airplanes), both dated March 24, 2005. Boeing Special 
Attention Service Bulletin 757-21-0106 describes procedures for 
installing clamps on the end caps of the overhead distribution ducts at 
stations 864.9, 866.6, and 875. Boeing Special Attention Service 
Bulletin 757-21-0107 describes procedures for installing clamps on the 
end caps of the overhead distribution ducts at stations 864.88 and 875. 
The service bulletins also describe procedures for doing other 
specified and related investigative actions if necessary. The other 
specified actions include the following:
     Removing any tie straps, if installed, from the end caps 
of the overhead distribution ducts.
     Pushing each end cap against the end of the overhead duct 
all the way around.
     Torquing the clamps.
    The related investigative actions include the following:
     Visually inspecting the end caps to ensure that each end 
cap has been pushed against the overhead duct all the way around.
     Ensuring that there is no air leakage from the end caps of 
the overhead ducts in the flight and passenger compartments in 
accordance with certain chapters of the Boeing 757 Airplane Maintenance 
Manual.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. For this reason, we are proposing this AD, 
which would require accomplishing the actions specified in the service 
information described previously.

Clarification of Compliance Time

    The service bulletins specify installing the clamps in 36 months or 
less, or 12,000 flight hours or less from the release date of the 
service bulletin. However, the proposed AD would require installing the 
clamps within 12,000 total flight hours or within 36 months after the 
effective date of this AD, whichever is first.

Clarification of Inspection Terminology

    Figure 1 of both service bulletins specifies to inspect the end 
caps ``visually.'' This proposed AD, however, would require doing a 
general visual inspection of the end caps. Paragraph 3.A. of the 
service bulletin includes the definition for a general visual 
inspection.

Costs of Compliance

    There are about 63 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 37 airplanes of 
U.S. registry. The proposed actions would take about 1 work hour per 
airplane, at an average labor rate of $65 per work hour. Required parts 
would cost between $20 and $40 per airplane, depending on airplane 
configuration. Based on these figures, the estimated cost of the 
proposed AD for U.S. operators is between $3,145 and $3,885, or between 
$85 and $105 per airplane, depending on airplane configuration.

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 proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the

[[Page 73665]]

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 the 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. 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 proposed AD and placed it in the AD docket. 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, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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.

Sec.  39.13  [Amended]

    2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-23282; Directorate Identifier 2005-NM-
210-AD.

Comments Due Date

    (a) The FAA must receive comments on this AD action by January 
27, 2006.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to airplanes identified in paragraphs (c)(1) 
and (c)(2) of this AD, certificated in any category.
    (1) Boeing Model 757-200 series airplanes, having certain 
variable numbers as identified in Boeing Special Attention Service 
Bulletin 757-21-0106, dated March 24, 2005.
    (2) Boeing Model 757-300 series airplanes, having certain 
variable numbers as identified in Boeing Special Attention Service 
Bulletin 757-21-0107, dated March 24, 2005.

Unsafe Condition

    (d) This AD results from finding that the end caps of the 
overhead distribution ducts for the air conditioning system were not 
bonded to the ducts with an adhesive. We are issuing this AD to 
detect and correct loosened end caps, which could change the air 
flow balance in the airplane. During a smoke event in the cargo or 
main electronics compartments, the incorrect balance of air flow 
could change the smoke clearance air capacity and result in smoke 
and toxic fumes penetrating the flight deck and main cabin.

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.

Service Bulletin References

    (f) The term ``service bulletin,'' as used in this AD, means the 
Accomplishment Instructions of the following service bulletins, as 
applicable:
    (1) For Model 757-200 series airplanes: Boeing Special Attention 
Service Bulletin 757-21-0106, dated March 24, 2005; and
    (2) For Model 757-300 series airplanes: Boeing Special Attention 
Service Bulletin 757-21-0107, dated March 24, 2005.

Install Clamps

    (g) Within 12,000 flight hours or 36 months after the effective 
date of this AD, whichever is first: Install clamps on the end caps 
of the overhead distribution ducts of the air conditioning system at 
stations 864.88, 864.9, 866.6, and 875, as applicable, and before 
further flight do any other specified and related investigative 
actions as applicable, by doing all of the applicable actions 
specified in the applicable service bulletin.

Alternative Methods of Compliance (AMOCs)

    (h)(1) The Manager, Seattle Aircraft Certification Office, FAA, 
has the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.

    Issued in Renton, Washington, on December 6, 2005.
Kevin M. Mullin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-23956 Filed 12-12-05; 8:45 am]
BILLING CODE 4910-13-P