[Federal Register Volume 59, Number 71 (Wednesday, April 13, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-8686]
[[Page Unknown]]
[Federal Register: April 13, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-29-AD; Amendment 39-8879; AD 94-08-07]
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 revising the FAA-approved
Airplane Flight Manual (AFM) to ensure that the flight crews verify the
accuracy of data provided by the Flight Management Computer (FMC) under
certain conditions. This amendment is prompted by a report that certain
FMC's may provide erroneous V speed data under certain conditions. The
actions specified in this AD are intended to prevent the airplane from
failing to achieve sufficient climb gradient, which may result in the
airplane failing to achieve obstacle clearance.
DATES: Effective April 28, 1994.
Comments for inclusion in the Rules Docket must be received on or
before June 13, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-29-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
Information concerning this amendment may be obtained from or
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue,
SW., Renton, Washington; or at the FAA, Transport Airplane Directorate,
Los Angeles Aircraft Certification Office, 3229 East Spring Street,
Long Beach, California.
FOR FURTHER INFORMATION CONTACT: Thomas A. Enyart, Aerospace Engineer,
Flight Test Branch, ANM-162L, FAA, Transport Airplane Directorate, Los
Angeles Aircraft Certification Office, 3229 East Spring Street, Long
Beach, California 90806-2425; telephone (310) 988-5372; fax (310) 988-
5210.
SUPPLEMENTARY INFORMATION: Recently, an operator of McDonnell Douglas
Model MD-11 series airplanes reported that certain Honeywell Flight
Management Computers (FMC) provided erroneous V speed data when the
anti-ice system was turned ON during flex (assumed) temperature
takeoffs. Investigation into this problem revealed that the takeoff
decision speed (V1) could be as low as 12 knots below the V1
speed data published in the FAA-approved Airplane Flight Manual (AFM),
and the rotation speed (VR) could be as low as 4 knots below the
VR speed data published in the FAA-approved AFM. An airplane
rotating at low VR speeds could reach 35 feet at a speed less than
the published minimum safety speed (V2). This condition, if not
corrected, could result in these airplanes failing to achieve
sufficient climb gradient, which may lead to these airplanes failing to
achieve obstacle clearance.
The FMC's installed on Model MD-11 series airplanes are identical
to those installed Model MD-11F series airplanes.
Since an unsafe condition has been identified that is likely to
exist or develop on other McDonnell Douglas Model MD-11 and MD-11F
series airplanes of the same type design equipped with certain
Honeywell FMC's, this AD is being issued to prevent these airplanes
from failing to achieve sufficient climb gradient, which may result in
these airplanes failing to achieve obstacle clearance. This AD requires
revising the FAA-approved AFM to ensure that the flight crews verify
the accuracy of data provided by the FMC when the anti-ice system is
turned ON during flex temperature takeoffs.
This is considered to be interim action. The manufacturer of these
airplanes is currently developing new software, in concert with the
manufacturer of the FMC, that will address the unsafe condition
addressed by this AD. Once this software is developed, approved, and
available, the FAA may consider additional rulemaking.
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-29-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, 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:
94-08-07 McDonnell Douglas: Amendment 39-8879. Docket 94-NM-29-AD.
Applicability: Model MD-11 and MD-11F series airplanes equipped
with Honeywell Flight Management Computers having part numbers
4059050-906, -907, and -908; certificated in any category.
Compliance: Required as indicated, unless accomplished
previously.
To prevent the airplane from failing to achieve sufficient climb
gradient, which may result in the airplane failing to achieve
obstacle clearance, accomplish the following:
(a) Within 20 days after the effective date of this AD, revise
the Limitations Section (Section 1) of the FAA-approved Airplane
Flight Manual (AFM), page 5-1, FLIGHT GUIDANCE, Flight Management
System (FMS) Section, to include the following information. This may
be accomplished by inserting a copy of this AD or an FAA-approved
McDonnell Douglas AFM revision in the AFM.
For any approved thrust level, the FMS computed V1,
VR, and V2 must be verified with AFM derived data, unless
all of the following conditions are met:
Dry Runway.
Balanced Field Length.
Ice Protection OFF.
(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), FAA, Transport Airplane Directorate. Operators shall
submit their requests through an appropriate FAA Principal
Operations 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
Federal Aviation Regulations (FAR) 21.197 and 21.199 to operate the
airplane to a location where the requirements of this AD can be
accomplished.
(d) This amendment becomes effective on April 28, 1994.
Issued in Renton, Washington, on April 6, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-8686 Filed 4-12-94; 8:45 am]
BILLING CODE 4910-13-U