[Federal Register Volume 60, Number 31 (Wednesday, February 15, 1995)]
[Proposed Rules]
[Pages 8591-8593]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-3752]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-251-AD]
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 supersedure of an existing
airworthiness directive (AD), applicable to certain Boeing Model 747-
400 series airplanes, that currently requires a revision to the input
wiring for the flap control unit. This action would require a new
systems test for the wiring of the trailing edge flap. The proposal
would also expand the applicability of the existing AD to include
additional airplanes. This proposal is prompted by a report indicating
that a wiring error was not detected by the system test required by the
existing AD. The actions specified by the proposed AD are intended to
prevent the possibility of an all-flaps-up landing due to the loss of
control of all flap operations.
DATES: Comments must be received by April 10, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
[[Page 8592]] Attention: Rules Docket No. 94-NM-251-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.
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: Kristin Larson, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, Seattle Aircraft Certification
Office, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056; telephone (206) 227-1760; fax (206) 227-
1181.
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 notice may be changed in
light of the comments received.
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 notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 94-NM-251-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-103, Attention: Rules
Docket No. 94-NM-251-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On July 1, 1994, the FAA issued AD 94-14-21, amendment 39-8970 (59
FR 35240, July 11, 1994), applicable to certain Boeing Model 747-400
series airplanes, to require a revision to the input wiring for the
flap control unit (FCU). That action was prompted by reports of
disconnection of the Landing Gear Module electrical connectors, which
can result in the loss of the primary, secondary, and alternate control
of the flaps. The requirements of that AD are intended to prevent the
possibility of an all-flaps-up landing due to the loss of control of
all flap operations.
Since issuance of that AD, an operator has reported a wiring error
of the Landing Gear Module that was not detected by the system test
(Work Package I) required by AD 94-14-21, and described in Boeing
Service Bulletin 747-27A2346, Revision 1, dated May 19, 1994. This
wiring error could allow the connectors to become disconnected, and all
FCU modes of flap operation (primary, secondary, and alternate control
of flaps) could be lost. This condition, if not corrected, could result
in all-flaps-up landing due to the loss of control of all flap
operations.
The FAA has reviewed and approved Boeing Service Bulletin 747-
27A2346, Revision 2, dated January 12, 1995, which provides procedures
for a systems test (Work Package II) of the trailing edge flap to
detect incorrect wiring. It also expands the effectivity listing to
include additional affected airplanes.
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 supersede AD 94-14-21 to continue to require revision
of the input wiring for the flap control unit, but would include the
addition of a new systems test for the wiring of the trailing edge
flap. The proposed AD also would expand the applicability of the
existing AD to include additional airplanes. The actions would be
required to be accomplished in accordance with the service bulletin
described previously.
As a result of recent communications with the Air Transport
Association (ATA) of America, the FAA has learned that, in general,
some operators may misunderstand the legal effect of AD's on airplanes
that are identified in the applicability provision of the AD, but that
have been altered or repaired in the area addressed by the AD. The FAA
points out that all airplanes identified in the applicability provision
of an AD are legally subject to the AD. If an airplane has been altered
or repaired in the affected area in such a way as to affect compliance
with the AD, the owner or operator is required to obtain FAA approval
for an alternative method of compliance with the AD, in accordance with
the paragraph of each AD that provides for such approvals. A note has
been included in this notice to clarify this requirement.
There are approximately 310 Model 747-400 series airplanes of the
affected design in the worldwide fleet. The FAA estimates that 36
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately .5 work hours per airplane to accomplish
the proposed actions, and that the average labor rate is $60 per work
hour. Based on these figures, the total cost impact of the proposed AD
on U.S. operators is estimated to be $1,080, or $30 per airplane.
The total 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 AD were not adopted.
The regulations proposed herein would not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
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.
[[Page 8593]]
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-8970 (59 FR
35240, July 11, 1994), and by adding a new airworthiness directive
(AD), to read as follows:
Boeing: Docket 94-NM-251-AD. Supersedes AD 94-14-21, Amendment 39-
8970.
Applicability: Model 747-400 series airplanes having line
numbers 696 through 1036 inclusive; certificated in any category.
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 use the authority
provided in paragraph (d) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition; or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
Note 2: Paragraph (a) of this AD merely restates the
requirements of paragraph (a) of AD 94-14-21, amendment 39-8970. As
allowed by the phrase, ``unless accomplished previously,'' if those
requirements of AD 94-14-21 have already been accomplished, this AD
does not require that those actions be repeated.
To prevent the possibility of an all-flaps-up landing due to the
loss of control of flap operations, accomplish the following:
(a) For airplanes having serial numbers 696 through 1019
inclusive, and 1021 through 1026 inclusive: Within 30 days after
August 10, 1994 (the effective date of AD 94-14-21, amendment 39-
8970), revise the input wiring for the flap control unit (FCU) in
accordance with Boeing Service Bulletin 747-27A2346, Revision 1,
dated May 19, 1994, or Revision 2, dated January 12, 1995.
(b) For airplanes having serial numbers 1020, and 1027 through
1036 inclusive: Within 30 days after the effective date of this AD,
revise the input wiring for the FCU in accordance with Boeing
Service Bulletin 747-27A2346, Revision 2, dated January 12, 1995.
(c) For airplanes having serial numbers 696 through 1036
inclusive: Within 120 days after the effective date of this AD,
perform the additional systems test for the wiring of the trailing
edge flap in accordance with Boeing Service Bulletin 747-27A2346,
Revision 2, dated January 12, 1995.
(d) 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, Transport Aircraft Directorate. 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(e) 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. Issued in Renton,
Washington, on February 9, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-3752 Filed 2-14-95; 8:45 am]
BILLING CODE 4910-13-U