[Federal Register Volume 70, Number 60 (Wednesday, March 30, 2005)]
[Proposed Rules]
[Pages 16175-16177]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-6250]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2005-20726; Directorate Identifier 2004-NM-265-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 757-200, -200CB, and -
200PF Series Airplanes

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

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for certain Boeing Model 757-200, -200CB, and -200PF series airplanes. 
This proposed AD would require an inspection of each trailing edge flap 
transmission assembly to determine the part number and serial number, 
and related investigative and corrective actions and part marking if 
necessary. This proposed AD is prompted by a report indicating that 
cracked flap transmission output gears have been discovered during 
routine overhaul of the trailing edge flap transmission assemblies. We 
are proposing this AD to prevent an undetected flap skew, which could 
result in a flap loss, damage to adjacent airplane systems, and 
consequent reduced controllability of the airplane.

DATES: We must receive comments on this proposed AD by May 16, 2005.

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.
     By 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.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department

[[Page 16176]]

of Transportation, 400 Seventh Street SW., room PL-401, on the plaza 
level of the Nassif Building, Washington, DC. This docket number is 
FAA-2005-20726; the directorate identifier for this docket is 2004-NM-
265-AD.

FOR FURTHER INFORMATION CONTACT: Douglas Tsuji, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6487; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

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 under ADDRESSES. Include ``Docket No. FAA-2005-20726; 
Directorate Identifier 2004-NM-265-AD'' in the subject line 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 submitted 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 website, 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 can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.

Examining the Docket

    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 (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 DMS receives them.

Discussion

    We have received a report indicating that cracked flap transmission 
output gears have been discovered during routine overhaul of the 
trailing edge flap transmission assemblies on certain Boeing Model 757-
200, -200CB, and -200 PF series airplanes. Investigation revealed that 
the cracks are the result of a manufacturing error in the production of 
transmission assemblies having certain part numbers and serial numbers. 
A damaged output gear could result in a disconnect within the flap 
transmission and cause an undetected flap skew. An undetected flap 
skew, if not corrected, could result in a flap loss, damage to adjacent 
airplane systems, and consequent reduced controllability of the 
airplane.

Relevant Service Information

    We have reviewed Boeing Special Attention Service Bulletin 757-27-
0150, dated December 9, 2004. The service bulletin describes procedures 
for inspecting each trailing edge flap transmission assembly to 
determine the part number and serial number, and related investigative 
and corrective actions if necessary. The related investigative and 
corrective actions include removing the transmission output gear from 
the affected transmission assembly, performing a magnetic particle 
inspection of the output gear, and replacing the output gear with a new 
output gear if any cracks or defects are found. The service bulletin 
also includes procedures for marking the nameplate of a trailing edge 
flap transmission assembly with the service bulletin number to indicate 
that the inspection of the output gear has been completed. 
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. Therefore, we are proposing this AD, which 
would require accomplishing the actions specified in the service 
information described previously.

Costs of Compliance

    There are about 979 airplanes of the affected design in the 
worldwide fleet. This proposed AD would affect about 644 airplanes of 
U.S. registry.
    It will take approximately 1 work hour per airplane to accomplish 
the proposed inspection at an average labor rate of $65 per work hour. 
Based on this figure, the cost impact of the proposed AD on U.S. 
operators is estimated to be $41,860, or $65 per airplane.
    Removal of a transmission assembly; removal, inspection, and 
reassembly of the transmission output gear; and reinstallation of the 
transmission assembly; if required; will take about 20 work hours per 
transmission assembly, at an average labor rate of $65 per work hour. 
Required parts will cost about $325 per transmission output gear. Based 
on these figures, we estimate the cost of replacement to be $1,625 per 
transmission output assembly (there are 8 transmission output 
assemblies per airplane and 325 suspect assemblies).

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 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. See the ADDRESSES

[[Page 16177]]

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 FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20726; Directorate Identifier 2004-NM-
265-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by May 16, 2005.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to Boeing Model 757-200, -200CB, and -200PF 
series airplanes, certificated in any category, as identified in 
Boeing Special Attention Service Bulletin 757-27-0150, dated 
December 9, 2004.

Unsafe Condition

    (d) This AD was prompted by a report indicating that cracked 
flap transmission output gears have been discovered during routine 
overhaul of the trailing edge flap transmission assemblies. We are 
issuing this AD to prevent an undetected flap skew, which could 
result in a flap loss, damage to adjacent airplane systems, and 
consequent reduced controllability of the airplane.

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.

Inspection To Determine Part Number and Serial Number

    (f) Within 60 months after the effective date of this AD: Do an 
inspection of each trailing edge flap transmission assembly to 
determine the part number and serial number, and any applicable 
related investigative and corrective actions and part marking, by 
accomplishing all of the applicable actions specified in the 
Accomplishment Instructions of Boeing Special Attention Service 
Bulletin 757-27-0150, dated December 9, 2004. If, during any related 
investigative action, any transmission output gear is found with a 
defect or crack, replace that transmission output gear before 
further flight.

Parts Installation

    (g) As of the effective date of this AD, no person may install a 
trailing edge flap transmission assembly, part number (P/N) 
251N4050-37, -38, -39, or -40, having any serial number (S/N) 001 
through 325 inclusive; or P/N 251N4022-28, -29, -30, or -31, having 
any S/N 001 through 325 inclusive; on any airplane; unless the 
transmission assembly has been inspected, and any applicable related 
investigative and corrective actions and part marking has been 
accomplished, in accordance with the Accomplishment Instructions of 
Boeing Special Attention Service Bulletin 757-27-0150, dated 
December 9, 2004.

Alternative Methods of Compliance (AMOCs)

    (h) 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.

    Issued in Renton, Washington, on March 21, 2005.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 05-6250 Filed 3-29-05; 8:45 am]
BILLING CODE 4910-13-P