[Federal Register Volume 59, Number 87 (Friday, May 6, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-10776]
[[Page Unknown]]
[Federal Register: May 6, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-57-AD; Amendment 39-8910; AD 94-10-03]
Airworthiness Directives; McDonnell Douglas Model MD-11 and MD-
11F Series Airplanes Equipped With Honeywell Flight Management
Computers
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to certain McDonnell Douglas Model MD-11 and MD-11F
series airplanes. This action requires deactivation of the Visual
Omnidirectional Receiver/Localizer (VOR/LOC) option by revising the
program pin wiring for the Flight Management Computer/Flight Control
Computer (FMC/FCC). This amendment is prompted by reports of
uncommanded roll mode changes on these airplanes during takeoff and
landing due to incorrect initialization of VOR/LOC logic within the
FMC. The actions specified in this AD are intended to prevent the
airplane from deviating from its intended flight path due to an
uncommanded change in the course of direction.
DATES: Effective on May 23, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of May 23, 1994.
Comments for inclusion in the Rules Docket must be received on or
before July 5, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-57-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
The service information referenced in this AD may be obtained from
McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, California
90801-1771, Attention: business Unit Manager, Technical Administrative
support, Dept. L51, M.C. 2-98. This information may be examined at the
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington; or at the FAA, Los Angeles Aircraft Certification Office,
Transport Airplane Directorate, 3229 East Spring Street, Long Beach,
California; or at the Office of the Federal Register, 800 North Capitol
Street, NW., suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Natalie Phan-Tran, Aerospace Engineer,
Systems & Equipment Branch, ANM-130L, Los Angeles Aircraft
Certification Office, FAA, Transport Airplane Directorate, 3229 East
Spring Street, Long Beach, California 90806-2425; telephone (310) 988-
5343; fax (310) 988-5210.
SUPPLEMENTARY INFORMATION: The FAA has received reports of uncommanded
roll mode changes that have occurred on McDonnell Douglas Model MD-11
series airplanes during takeoff and landing. The airplanes involved in
these incidents have been equipped with Honeywell Flight Management
Computers (FMC) having part numbers 4059050-907 and 4059050-908. The
incidents occurred when these FMC's were operating with the Visual
Omnidirectional Receiver/Localizer (VOR/LOC) option selected.
Investigation revealed that these incidents of uncommanded roll
mode changes were caused by one of the two FMC's not automatically
resetting or clearing all VOR mode logic upon landing. If the VOR mode
was selected on the previous inbound flight, and if this VOR mode is
not automatically cleared after the airplane lands, the VOR logic may
remain valid (in operation) in one of the two FMC's onboard the
airplane. If, during a subsequent flight, the autoflight system is
engaged to the FMC that still has the valid VOR logic [either by
disconnecting the autopilot (AP) or by swapping autopilots (AP1 to AP2,
or vice versa) with the ``AUTOFLIGHT'' switch], that FMC will
automatically command the airplane into a VOR roll mode. The airplane
will then follow this VOR mode logic guidance and fly in a direction
not planned by the flight crew. Such an uncommanded change in course
direction, if not corrected, could result in the airplane deviating
from its intended flight path.
The FAA has reviewed and approved McDonnell Douglas MD-11 Alert
Service Bulletin A34-55, dated April 22, 1994, that describes
procedures for deactivating the VOR/LOC option on the subject Honeywell
FMC's by removing the VOR/LOC pin from the Flight Management Computer/
Flight Control Computer (FMC/FCC) configuration plug on the main
avionics rack. This procedure will minimize the possibility of
uncommanded roll mode changes.
Since an unsafe condition has been identified that is likely to
exist or develop on other Model MD-11 and MD-11F series airplanes of
the same type design, this AD is being issued to prevent the airplane
from deviating from its intended flight path due to an uncommanded
change in the course of direction. This AD requires deactivating the
VOR/LOC option on certain Honeywell FMC's by removing the VOR/LOC pin
from the FMC/FCC configuration plug on the main avionics rack. The
actions are required to be accomplished in accordance with the service
bulletin described previously.
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD 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-57-AD.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will 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 final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866. It has been determined further that this
action involves an emergency regulation under DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979). If it is determined
that this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket. A copy of it, if filed, may
be obtained from the Rules Docket at the location provided under the
caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration amends 14 CFR part
39 of the Federal Aviation Regulations 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
94-10-03 McDonnell Douglas: Amendment 39-8910. Docket 94-NM-57-AD.
Applicability: Model MD-11 and MD-11F series airplanes; equipped
with Honeywell Flight Management Computers having part numbers
4059050-907 or 4059050-908; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent the airplane from deviating from its intended flight
path due to an uncommanded change in the course of direction,
accomplish the following:
(a) Within 30 days after the effective date of this AD,
deactivate the Visual Omnidirectional Receiver/Localizer (VOR/LOC)
option by removing the VOR/LOC pin from the Flight Management
Computer/Flight Control Computer (FMC/FCC) configuration plug on the
main avionics rack, in accordance with McDonnell Douglas MD-11 Alert
Service Bulletin A34-55, dated April 22, 1994.
(b) 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, Los Angeles Aircraft Certification
Office (ACO). Operators shall submit their requests through an
appropriate FAA Principal Avionics Inspector, who may add comments
and then send it to the Manager, Los Angeles ACO.
Note: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Los Angeles ACO.
(c) 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.
(d) The deactivation procedure shall be done in accordance with
McDonnell Douglas MD-11 Alert Service Bulletin A34-55, dated April
22, 1994. This incorporation by reference was approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR Part 51. Copies may be obtained from McDonnell Douglas
Corporation, P.O. Box 1771, Long Beach, California 90801-1771,
Attention: business Unit Manager, Technical Administrative support,
Dept. L51, M.C. 2-98. Copies may be inspected at the FAA, Transport
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or
at the FAA, Los Angeles Aircraft Certification Office, Transport
Airplane Directorate, 3229 East Spring Street, Long Beach,
California; or at the Office of the Federal Register, 800 North
Capitol Street, NW., suite 700, Washington, DC.
(e) This amendment becomes effective on May 23, 1994.
Issued in Renton, Washington, on April 29, 1994.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-10776 Filed 5-5-94; 8:45 am]
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