[Federal Register Volume 63, Number 86 (Tuesday, May 5, 1998)]
[Rules and Regulations]
[Pages 24742-24744]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11808]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-131-AD; Amendment 39-10512; AD 98-10-01]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model MD-11 Series 
Airplanes

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 series 
airplanes. This action requires a revision of the Airplane Flight 
Manual to alert the flightcrew that both flight management computers 
(FMC's) must be installed and operational. This AD also requires an 
inspection to determine the serial number of the FMCs, and follow-on 
corrective actions, if necessary. This amendment is prompted by a 
report indicating that, due to incorrect multiplexers that were 
installed in the flight management computer system (FMC'S) during 
production, certain data busses failed simultaneously during a ground 
test. The actions specified in this AD are intended to prevent loss of 
airspeed and altitude indications on both primary flight displays in 
the cockpit, and/or loss or degradation of the autopilot functionality 
due to installation of incorrect multiplexers, and consequent failure 
of the data busses.

DATES: Effective May 20, 1998.
    The incorporation by reference of certain publications listed in 
the

[[Page 24743]]

regulations is approved by the Director of the Federal Register as of 
May 20, 1998.
    Comments for inclusion in the Rules Docket must be received on or 
before July 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-131-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The service information referenced in this AD may be obtained from 
The Boeing Company, Douglas Products Division, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Dept. C1-L51 (2-60). This information may be 
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, 3960 Paramount Boulevard, 
Lakewood, California; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Brett Portwood, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Transport Airplane 
Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5350; 
fax (562) 627-5210.

SUPPLEMENTARY INFORMATION: The FAA received a report indicating that, 
during a routine ground test on an Airbus Model A310 series airplane, 
which included a power-down test of the Honeywell Flight Management 
Computer System (FMCS), multiple ARINC 429 data busses failed 
simultaneously. Investigation revealed that a batch of incorrect 
multiplexers were installed in the FMCS during production, which can 
cause loading of the ARINC 429 data busses when the flight management 
computer (FMC) is de-energized. This condition, if not corrected, could 
result in loss of airspeed and altitude indications on both primary 
flight displays in the cockpit and/or loss or degradation of the 
autopilot functionality.

Similar Airplanes

    The FMCS of Airbus Model A310 series airplanes is similar in design 
to that of McDonnell Douglas Model MD-11 series airplanes. Therefore, 
the FAA has determined that Model MD-11 series airplanes may be subject 
to the same unsafe condition. The FAA has been advised that the 
Direction Generale de l'Aviation Civile (DGAC), which is the 
airworthiness authority for France, may consider issuing a parallel 
French airworthiness directive to correct the identified unsafe 
condition on Airbus Model A310 series airplanes.

Explanation of Relevant Service Information

    The FAA has reviewed and approved McDonnell Douglas Alert Service 
Bulletin MD11-34A083, dated April 6, 1998, which describes procedures 
for a visual inspection to determine the serial number of the FMC's, 
and follow-on corrective actions, if necessary. The follow-on 
corrective actions include, for any airplane on which an affected 
serial number is found, a visual inspection to determine the part 
number of the multiplexer, and modification of certain multiplexers. In 
addition, the alert service bulletin describes procedures for a 
functional test of the FMC in the flight compartment to determine if an 
incorrect multiplexer is installed, and corrective actions, if 
necessary.
    McDonnell Douglas Alert Service Bulletin MD11-34A083, dated April 
6, 1998, references Honeywell Service Bulletin 4059050-34-0011, dated 
March 12, 1998, as an additional source of service information.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, this AD is 
being issued to prevent loss of airspeed and altitude indications on 
both primary flight displays in the cockpit, and/or loss or degradation 
of the autopilot functionality as a result of incorrect multiplexers 
installed in the FMCS. This AD requires revising the Limitations 
Section of the FAA-approved Airplane Flight Manual (AFM) to alert the 
flightcrew that, prior to dispatch, both FMC's must be installed and 
operational.
    This AD also requires accomplishment of the actions specified in 
the alert service bulletin described previously, except as discussed 
below.

Differences Between Rule and Alert Service Bulletin

    Operators should note that, although the alert service bulletin 
describes procedures for a functional test, this AD does not require 
that functional test. The FAA has determined that the functional test 
does not positively indicate that an incorrect multiplexer is 
installed.

Interim Action

    This is considered to be interim action. The FAA is considering 
further rulemaking action to supersede this AD to require modification 
of any FMC that does not have an affected serial number (i.e., 
Condition 2 of the Work Instructions in the referenced alert service 
bulletin). However, the planned compliance time for these actions is 
sufficiently long so that notice and opportunity for prior public 
comment will be practicable.

Determination of Rule's Effective Date

    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 rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-NM-131-AD.'' The postcard will be date stamped and 
returned to the commenter.

[[Page 24744]]

Regulatory Impact

    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 that it 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 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:

98-10-01  McDonnell Douglas: Amendment 39-10512. Docket 98-NM-131-
AD.

    Applicability: Model MD-11 series airplanes, manufacturer's 
fuselage numbers 0447 through 0552 inclusive, and 0554 through 0621 
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 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 loss of airspeed and altitude indications on both 
primary flight displays in the cockpit and/or loss or degradation of 
the autopilot functionality, due to installation of incorrect 
multiplexers in the flight management computer system (FMCS), 
accomplish the following:
    (a) Within 5 days after the effective date of this AD, revise 
Section 1, page 5-1 of the Limitations Section of the FAA-approved 
Airplane Flight Manual (AFM) to include the following statement. 
This may be accomplished by inserting a copy of this AD into the 
AFM.
    ``Prior to dispatch of the airplane, both Flight Management 
Computer 1 (FMC-1) and FMC-2 must be installed and operational.''
    (b) Within 45 days after the effective date of this AD, perform 
a visual inspection to determine the serial number of the flight 
management computers (FMC), in accordance with McDonnell Douglas 
Alert Service Bulletin MD11-34A083, dated April 6, 1998. After this 
inspection is accomplished, the AFM revision required by paragraph 
(a) of this AD may be removed from the AFM.
    (1) If no affected serial number is found, no further action is 
required by this paragraph.
    (2) If any affected serial number is found, prior to further 
flight, perform a visual inspection to determine the part number (P/
N) of the multiplexer, in accordance with the alert service 
bulletin. If any affected P/N is found, prior to further flight, 
modify the multiplexer in accordance with the alert service 
bulletin.

    Note 2: McDonnell Douglas Alert Service Bulletin MD11-34A083, 
dated April 6, 1998, references Honeywell Service Bulletin 4059050-
34-0011, dated March 12, 1998, as an additional source of service 
information.

    (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, Los Angeles Aircraft Certification 
Office (ACO), FAA, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (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.
    (e) Except as provided for in paragraph (a) of this AD, the 
actions shall be done in accordance with McDonnell Douglas Alert 
Service Bulletin MD11-34A083, dated April 6, 1998. 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 The Boeing Company, Douglas Products 
Division, 3855 Lakewood Boulevard, Long Beach, California 90846, 
Attention: Technical Publications Business Administration, Dept. C1-
L51 (2-60). Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
FAA, Transport Airplane Directorate, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, 
California; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (f) This amendment becomes effective on May 20, 1998.

    Issued in Renton, Washington, on April 28, 1998.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-11808 Filed 5-4-98; 8:45 am]
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