[Federal Register Volume 68, Number 154 (Monday, August 11, 2003)]
[Proposed Rules]
[Pages 47513-47515]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-20389]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-173-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 747-400, -400D, and -400F 
Series Airplanes Equipped With General Electric (GE) or Pratt & Whitney 
(P&W) Series Engines

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, -
400D, and -400F series airplanes; equipped with GE or P&W series 
engines. This proposal would require modifications and functional tests 
of the wiring of the wire integration unit and the air supply control 
test unit (ASCTU) of the engine bleed air distribution system. This 
action is necessary to prevent inadvertent commanded shutdown of the 
engine bleed air distribution systems due to an erroneous ASCTU 
command. Such a shutdown could cause depressurization of the airplane 
and subsequent ice build-up on the engine inlets during descent, which 
could result in ingestion of ice into the engine(s) and consequent loss 
of thrust on one or more engines. This action is intended to address 
the identified unsafe condition.

DATES: Comments must be received by September 25, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-173-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 p.m., Monday through Friday, except 
Federal holidays. Comments may be submitted via fax to (425) 227-1232. 
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-173-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 or 2000 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: Don Eiford, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6465; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

[[Page 47514]]

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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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 Number 2002-NM-173-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 No. 2002-NM-173-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received a report from one operator that, on two 
separate occasions, there was a loss of airflow from all four bleed air 
distribution systems on a Model 747 series airplane. Investigation 
revealed that there were incorrect connections of certain jumper wires 
to the air supply control test unit (ASCTU) that caused it to indicate 
an erroneous strut overheat condition. When the ASCTU is in the 
identified configuration, as found in the airplane incident above, it 
erroneously senses a strut overheat input. When the ASCTU identifies a 
strut overheat condition, the ASCTU will command shutdown of the bleed 
air distribution systems. The ASCTU will identify a normal condition 
instead of a strut overheat condition if the jumper wires are installed 
properly.
    Inadvertent commanded shutdown of the engine bleed air distribution 
systems due to an erroneous ASCTU command, could cause depressurization 
of the airplane and subsequent ice build-up on the engine inlets during 
descent, which could result in ingestion of ice into the engine(s) and 
consequent loss of thrust on one or more engines.

Explanation of Relevant Service Information

    The FAA has reviewed and approved Boeing Service Bulletin 747-
36A2136, Revision 1, dated January 17, 2002, which describes procedures 
for modifications and resistance tests and post-installation ASCTU 
tests of the wiring of the wire integration unit (WIU) and the ASCTU of 
the engine bleed air distribution system. The modifications include 
wiring changes between the WIU and ASCTU, and wiring changes to the 
WIU.
    The Boeing service bulletin specifies accomplishment of Hamilton 
Sundstrand Service Bulletin 36-186, dated March 30, 2001. The Hamilton 
Sundstrand service bulletin describes procedures for modification of 
the ASCTU by reworking the circuit card assemblies of the bleed 
controllers.
    Accomplishment of the actions specified in the service bulletins 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 bulletins described previously.

Changes to 14 CFR Part 39/Effect on the Proposed AD

    On July 10, 2002, the FAA issued a new version of 14 CFR part 39 
(67 FR 47997, July 22, 2002), which governs the FAA's airworthiness 
directives system. The regulation now includes material that relates to 
altered products, special flight permits, and alternative methods of 
compliance. Because we have now included this material in part 39, we 
no longer need to include it in each individual AD; however, this AD 
identifies the office authorized to approve alternative methods of 
compliance.

Work Hour Rate Increase

    We have reviewed the figures we use to calculate the labor rate to 
do the required actions. To account for various inflationary costs in 
the airline industry, we find it appropriate to increase the labor rate 
used in these calculations from $60 per work hour to $65 per work hour. 
The economic impact information, below, has been revised to reflect 
this increase in the specified hourly labor rate.

Cost Impact

    There are approximately 414 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 70 airplanes of U.S. registry 
would be affected by this proposed AD, that it would take approximately 
8 work hours per airplane to accomplish the proposed modifications and 
functional tests, and that the average labor rate is $65 per work hour. 
Required parts would be minimal. Based on these figures, the cost 
impact of the proposed modifications on U.S. operators is estimated to 
be $36,400, or $520 per airplane.
    The cost impact figure discussed above is 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 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

[[Page 47515]]

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-173-AD.

    Applicability: Model 747-400, -400D, and -400F series airplanes; 
as listed in Boeing Service Bulletin 747-36A2136, Revision 1, dated 
January 17, 2002; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent inadvertent commanded shutdown of the engine bleed 
air distribution systems due to an erroneous air supply control test 
unit (ASCTU) command, which could cause depressurization of the 
airplane and subsequent ice build-up on the engine inlets during 
descent, which could result in ingestion of ice into the engine(s) 
and consequent loss of thrust on one or more engines, accomplish the 
following:

Modifications/Tests

    (a) Within 18 months after the effective date of this AD: Do the 
modifications and functional tests of the wiring of the wire 
integration unit (WIU) and the ASCTU of the engine bleed air 
distribution system specified in paragraphs (a)(1), (a)(2), and 
(a)(3) of this AD, per the Accomplishment Instructions of Boeing 
Service Bulletin 747-36A2136, Revision 1, dated January 17, 2002.
    (1) Do the wiring changes between the WIU and ASCTU and the 
wiring changes to the WIU.
    (2) Remove the existing ASCTU and install a new or reworked 
ASCTU.
    (3) Before further flight after accomplishment of paragraphs 
(a)(1) and (a)(2) of this AD: Do the resistance tests and post-
installation tests.

Credit for Original Issue of Boeing Service Bulletin

    (b) Modifications and tests accomplished before the effective 
date of this AD per Boeing Alert Service Bulletin 747-36A2136, dated 
April 12, 2001, are considered acceptable for compliance with the 
corresponding actions specified in paragraph (a) of this AD.

Part Installation

    (c) As of the effective date of this AD, no person may install 
on any airplane an ASCTU having a part number listed in the ``Old 
Part Number'' column in the table specified in paragraph 3.C. of the 
Accomplishment Instructions of Hamilton Sundstrand Service Bulletin 
36-186, dated March 30, 2001.

Alternative Methods of Compliance

    (d) In accordance with 14 CFR 39.19, the Manager, Seattle 
Aircraft Certification Office, FAA, is authorized to approve 
alternative methods of compliance for this AD.

    Issued in Renton, Washington, on August 5, 2003.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 03-20389 Filed 8-8-03; 8:45 am]
BILLING CODE 4910-13-P