[Federal Register Volume 67, Number 125 (Friday, June 28, 2002)]
[Proposed Rules]
[Pages 43570-43572]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-16310]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-46-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 747-400 
series airplanes. This proposal would require repetitive inspections to 
detect discrepancies of the drip shield and supports located above the 
rudder pedal mechanisms; corrective action, if necessary; and eventual 
modification of the drip shield, which would terminate the repetitive 
inspections. This action is necessary to prevent unrestrained drip 
shields from interfering with the rudder pedal mechanism, which could 
result in reduced controllability of the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by August 12, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-46-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232.

[[Page 43571]]

Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-46-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 for Windows 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:   
    Technical Information: Clint Jones, Aerospace Engineer, Systems and 
Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-1622; fax (425) 227-1181.
    Other Information: Sandi Carli, Airworthiness Directive Technical 
Editor/Writer; telephone (425) 687-4243, fax (425) 227-1232. Questions 
or comments may also be sent via the Internet using the following 
address: [email protected]. Questions or comments sent via the 
Internet as attached electronic files must be formatted in Microsoft 
Word 97 for Windows or ASCII text.

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 2002-NM-46-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 2002-NM-46-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056.

Discussion

    The FAA has received reports of two occurrences of a limitation of 
rudder pedal travel from the neutral position. Investigation revealed 
that a drip shield, located in the ceiling of the forward passenger 
compartment, became unrestrained and dropped down onto the rudder pedal 
mechanism, causing the limitation. The FAA has also received reports of 
evidence marks on drip shields, indicating interference contact with 
the rudder pedal mechanism. Analysis by the manufacturer indicates that 
an unrestrained drip shield can limit rudder pedal movement by up to 
50% in one direction. (Movement in the opposite direction would be 
unaffected.) The limitation is caused by failure of the bonded drip 
shield supports, which would allow the drip shield to fall onto the 
rudder pedal mechanism. Limitation of rudder pedal movement could 
reduce the controllability of the airplane.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 747-
25A3271, Revision 1, dated December 19, 2001, which describes 
procedures for repetitive inspections of the drip shield and supports 
of the forward rudder quadrant to detect discrepancies (insufficient 
clearance from the components in the forward rudder quadrant, disbonded 
clip plates, and missing fasteners). Corrective actions include 
replacing missing fasteners and disbonded clip plates with new parts. 
The service bulletin also describes procedures for modifying the drip 
shield by installing blind rivets and changing the part numbers of the 
clip plates and drip shield, which would eliminate the need for the 
repetitive inspections. Accomplishment of the actions specified in the 
service bulletin is intended to adequately address the identified 
unsafe condition.

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, except as discussed below.

Differences Between Proposed AD and Service Bulletin

    The service bulletin recommends that the inspections be 
accomplished at regular ``C-check'' intervals. This proposed AD would 
require that the inspections be repeated every 3,000 flight hours 
(until the terminating action is accomplished). The FAA finds a 3,000-
flight-hour interval appropriate for affected airplanes to continue to 
operate without compromising safety. Because C-check schedules vary 
among operators, such a nonspecific interval would provide no assurance 
that operators would follow the prescribed actions within the 
prescribed schedule.

Cost Impact

    There are approximately 498 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 60 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the proposed inspection on 
U.S. operators is estimated to be $3,600, or $60 per airplane, per 
inspection cycle.
    It would take approximately 3 work hours per airplane to accomplish 
the proposed terminating action, at an average labor rate of $60 per 
work hour. The cost of required parts would be minimal. Based on these 
figures, the cost impact of the proposed terminating action on U.S. 
operators is estimated to be $10,800, or $180 per airplane.
    The cost impact figures discussed above are 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

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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.


Sec. 39.13  [Amended]

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

Boeing: Docket 2002-NM-46-AD.

    Applicability: Model 747-400 series airplanes, certificated in 
any category, as listed in Boeing Service Bulletin 747-25A3271, 
Revision 1, dated December 19, 2001.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For airplanes that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously. To prevent unrestrained drip shields from interfering 
with the rudder pedal mechanism, which could result in reduced 
controllability of the airplane, accomplish the following:

Repetitive Inspections

    (a) Within 1,200 flight hours after the effective date of this 
AD: Perform a general visual inspection of the drip shield and 
supports of the forward rudder quadrant to detect discrepancies 
(less than 0.50 inch clearance from the components in the forward 
rudder quadrant, disbonded clip plates, and missing fasteners), in 
accordance with Figure 1 of Boeing Service Bulletin 747-25A3271, 
Revision 1, dated December 19, 2001.

    Note 2: For the purposes of this AD, a general visual inspection 
is defined as: ``A visual examination of an interior or exterior 
area, installation, or assembly to detect obvious damage, failure, 
or irregularity. This level of inspection is made from within 
touching distance unless otherwise specified. A mirror may be 
necessary to enhance visual access to all exposed surfaces in the 
inspection area. This level of inspection is made under normally 
available lighting conditions such as daylight, hangar lighting, 
flashlight, or droplight and may require removal or opening of 
access panels or doors. Stands, ladders, or platforms may be 
required to gain proximity to the area being checked.''

    (1) If no discrepancy is found: Repeat the inspection thereafter 
at least every 3,000 flight hours until the terminating action 
required by paragraph (b) of this AD has been accomplished.
    (2) If any discrepancy is found during any inspection required 
by this paragraph: Before further flight, perform the specified 
corrective actions in accordance with Figure 1 of the service 
bulletin. Thereafter repeat the inspection at least every 3,000 
flight hours until the terminating action required by paragraph (b) 
of this AD has been accomplished.

    Note 3: Accomplishment before the effective date of this AD of 
an inspection and applicable corrective actions in accordance with 
Boeing Service Bulletin 747-25A3271, dated April 12, 2001, is 
acceptable for compliance with the initial inspection requirement of 
paragraph (a) of this AD.

Terminating Action

    (b) Within 2 years after the effective date of this AD, modify 
the drip shield by installing blind rivets in each clip plate and 
changing the part numbers of the clip plates and drip shield, in 
accordance with Figure 2 of Boeing Service Bulletin 747-25A3271, 
Revision 1, dated December 19, 2001.

Alternative Methods of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Seattle Aircraft Certification 
Office (ACO), FAA. Operators shall submit their requests through an 
appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Seattle ACO.

    Note 4: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.


Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-16310 Filed 6-27-02; 8:45 am]
BILLING CODE 4910-13-P