[Federal Register Volume 62, Number 35 (Friday, February 21, 1997)]
[Rules and Regulations]
[Pages 7930-7932]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3844]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-217-AD; Amendment 39-9934; AD 97-04-10]
RIN 2120-AA64


Airworthiness Directives; McDonnell Douglas Model DC-9-80 Series 
Airplanes, Model MD-88 Airplanes, and Model MD-90 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to all McDonnell Douglas Model DC-9-80 series 
airplanes, Model MD-88 airplanes, and Model MD-90 airplanes, that 
currently requires revising the Airplane Flight Manual (AFM) to include 
limitations and procedures to address situations in which the autopilot 
or autothrottle fails to disengage. That AD was prompted by incidents 
in which the flightcrew was unable to disconnect the autopilot or 
autothrottle function from the engaged position, due to a discrepancy 
in a microswitch that is associated with the operation of those 
functions. This amendment requires an inspection of the autopilot and 
autothrottle engage switches located in the flight guidance control 
panel, and installation of improved switches. Accomplishment of these 
actions will terminate the previous requirement for the AFM revision. 
The actions specified by this AD are intended to ensure that the 
autopilot and autothrottle disengage when commanded to do so by the 
flightcrew.

DATES: Effective March 28, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 28, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from McDonnell Douglas Corporation, 3855 Lakewood Boulevard, 
Long Beach, California 90846, Attention: Technical Publications 
Business Administration, Department C1-L51 (2-60). This information may 
be examined at the Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 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: J. Kirk Baker, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft 
Certification Office, 3960 Paramount Boulevard, Lakewood, California 
90712; telephone (310) 627-5345; fax (310) 627-5210.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 96-12-21, 
amendment 39-9664 (61 FR 29007, June 7, 1996), which is applicable to 
all McDonnell Douglas Model DC-9-80 series airplanes, Model MD-88 
airplanes, and Model MD-90 airplanes, was published in the Federal 
Register on September 30, 1996 (61 FR 51068). The action proposed to 
continue to require a revision of the Airplane Flight Manual (AFM) to 
include limitations and procedures to address situations in which the 
autopilot or autothrottle fails to disengage; this action was 
previously required by AD 96-12-21. However, the action also proposed 
to require an inspection of the autopilot and autothrottle engage 
switches located in the flight guidance control panel (FGCP), and 
replacement of the switches with improved switches. Accomplishment of 
these new actions would constitute terminating action for the previous 
requirement to revise the AFM.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    Two commenters support the proposed AD.

Request To Extend Compliance Time

    Several commenters support the intent of the proposed AD, but 
request that the compliance time for accomplishing the terminating 
action be extended from the proposed 120 days to as much as 3 years. 
These commenters are concerned that not enough replacement switches 
will be available to support the fleet within the proposed compliance 
time. One commenter, a U.S. operator, states that it owns 310 FGCP's 
that would need new switches installed, and its maintenance facilities 
currently can modify only 5 panels per week; to meet the proposed 
compliance schedule, this operator would have to employ 2 additional 
full-time mechanics at a cost of $80,000. One commenter, another a U.S. 
operator, states that Honeywell (the manufacturer of the switches) has 
indicated that it will not be able to supply the complete number of 
needed switches within the 120-day time period; Honeywell suggested 
that it will need at least 180 days just to produce the switches, and 
more time will be required for ordering and shipping.
    The FAA concurs that the compliance time can be extended. Honeywell 
has advised the FAA that it has re-evaluated the magnitude of the 
modification program and finds that it will not have an ample number of 
parts available to support the proposed 120-day compliance time for 
modification of the U.S. fleet. Based on the information provided by 
Honeywell, and in consideration of the number of airplanes that will be 
affected by the requirement to install the new switches, the FAA has 
determined that the compliance time can be extended to 12 months. 
Paragraph (c) of the final rule has been revised accordingly. The FAA 
finds that safety will not be compromised in the interim, since the 
currently-required AFM revision will remain in effect during that time.

Request To Revise Cost Impact Information

    Several commenters suggest that the cost impact information, which 
was presented in the preamble to the proposal, was underestimated. One 
commenter points out that, although the information in the referenced 
McDonnell Douglas service bulletin may indicate that only 1.5 work 
hours are required to accomplish the terminating action, that figure 
only reflects the labor necessary for removal and re-installation of a 
modified FGCP. It does not include the time that will be required for 
in-house shop rework of the parts (an additional 2 to 5 work hours) or, 
for some operators, the time necessary for removing the panels from the 
airplane, shipping them to Honeywell for modification, and returning 
them to the operator for installation (estimated to be as much as 270 
days).
    The FAA concurs that the cost impact figures should be updated. In 
general, the cost impact information relative to AD actions includes 
only the direct costs of the specific actions required by the AD. The 
number of work hours necessary to accomplish the terminating action, 
specified as 1.5 work hours in the proposal, represented the time 
necessary to perform only the actions actually required by the AD: 
inspection, removal, installation, and a functional check. That number 
was provided to the FAA by the airframe manufacturer, McDonnell 
Douglas, based on the best data available at that time. A Honeywell 
service bulletin that is related to the

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actions required by this AD indicates that 2.0 work hours would be 
required for modification of the panel. In consideration of this new 
information, the FAA has revised the cost impact information, below, to 
indicate that 3.5 work hours will be required to accomplish the 
terminating action.
    The FAA recognizes that, in accomplishing the requirements of any 
AD, operators may incur ``incidental'' costs in addition to the 
``direct'' costs. The cost analysis in AD rulemaking actions, however, 
typically does not include incidental costs, such as the time required 
to gain access and close up; planning time; ordering/shipping/delivery 
time for parts, or the time needed for other administrative actions. 
Because incidental costs may vary significantly from operator to 
operator, they are almost impossible to calculate.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    There are approximately 970 Model DC-9-80 series airplanes, Model 
MD-88 airplanes, and Model MD-90 airplanes of the affected design in 
the worldwide fleet. The FAA estimates that 512 airplanes of U.S. 
registry will be affected by this proposed AD.
    The AFM revision that was previously required by AD 96-12-21 and 
retained in this new AD takes approximately 1 work hour per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact of the currently required actions on 
U.S. operators is estimated to be $30,720, or $60 per airplane.
    The new actions that are required by this new AD will take 
approximately 3.5 work hours per airplane to accomplish (this figure 
includes inspection, removal, modification, re-installation, and a 
functional check), at an average labor rate of $60 per work hour. 
Required parts will be provided by the manufacturer at no charge to 
operators. Based on these figures, the cost impact of the new 
requirements of this AD on U.S. operators is estimated to be $107,520, 
or $210 per airplane.
    The cost impact figures discussed above are based on assumptions 
that no operator has yet accomplished any of the requirements of this 
AD action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.

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.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it 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 removing amendment 39-9664 (61 FR 
29007, June 7, 1996), and by adding a new airworthiness directive (AD), 
amendment 39-9934, to read as follows:

97-04-10  McDonnell Douglas: Amendment 39-9934. Docket 96-NM-217-AD. 
Supersedes AD 96-12-21, Amendment 39-9664.

    Applicability: Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 
(MD-83), DC-9-87 (MD-87), and Model MD-88 airplanes, as listed in 
McDonnell Douglas Service Bulletin MD80-22-122, dated August 6, 
1996; and Model MD-90 airplanes, as listed in McDonnell Douglas 
Service Bulletin MD90-22-005, dated August 6, 1996; certificated in 
any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 (d) 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 ensure the flight crew's ability to continue to control the 
airplane manually if the autopilot or autothrottle function fails to 
disengage, accomplish the following:
    (a) Within 14 days after June 24, 1996 (the effective date of AD 
96-12-21, amendment 39-9664), revise 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 
in the AFM.
    If the autopilot or autothrottle fails to disconnect normally, 
press and hold the autopilot release button or either autothrottle 
release button, as appropriate. Refer to the Abnormal Procedures 
section for procedures if the autopilot or autothrottle fails to 
disconnect.
    (b) Within 14 days after June 24, 1996 (the effective date of AD 
96-12-21, amendment 39-9664), revise the Abnormal Procedures section 
of the FAA-approved AFM to include the following information. This 
may be accomplished by inserting a copy of this AD in the AFM.

AUTOPILOT:

    If the Autopilot (A/P) disconnects when the AUTOPILOT RELEASE 
button on either control wheel is depressed, and re-engages when the 
AUTOPILOT RELEASE button is released, accomplish the following 
procedures:

PROCEDURE: Use Autopilot (as desired)

AUTOPILOT RELEASE button.................................PRESS AND HOLD

     Hold either yoke (yellow) Autopilot Release button 
while continuing to fly the aircraft manually. The A/P will remain 
disengaged while depressing the button.
     When the Autopilot Release button is released, the A/P 
will engage and all A/P functions should work normally.

TO SILENCE THE AURAL WARNING:

CAWS C/B (P-38)....................................................PULL
     Circuit breaker is located behind the Captain's seat.
     Pulling the C/B will disable the Stall Warning SSRS-1, 
Landing Gear, Takeoff, Cabin Altitude, Speed Brake aural warnings, 
in addition to the Autopilot aural warning.

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CAUTION:

    Do not attempt to overpower the autopilot. When the autopilot is 
engaged, applying force to the column may allow the alternate trim 
to reposition the stabilizer. If the force is applied long enough, 
it will result in an out-of-trim condition.''

``AUTOTHROTTLE:

    If the Autothrottle (A/T) disconnects when either throttle 
disconnect button is depressed, and re-engages when throttle 
disconnect button is released, accomplish the following procedures:

PROCEDURE: Use Autothrottle System (as desired)

    WHEN A DISCONNECT IS NECESSARY:

AUTOTHROTTLE RELEASE
  BUTTON PRESS AND HOLD

     Press and hold either button until flashing red A/T 
annunciation is illuminated. Flashing red light indicates 
autothrottle is disconnected.
     AUTOTHROTTLE RELEASE BUTTON may then be released.
     The FMA A/T window will annunciate as though the A/T is 
engaged.
     The flashing red A/T annunciation of the FMA cannot be 
extinguished with repeated depression of the autothrottle release 
button.
     If the throttle levers are retarded to the idle stop, 
the flashing red A/T annunciation will extinguish, and the A/T 
system will re-engage.
     If the DFGC is selected to the IAS mode and the A/T 
SPEED mode is selected, the A/T system will re-engage.''
    (c) Within 12 months after the effective date of this AD, 
accomplish the inspection and replacement of the autopilot and 
autothrottle engage switches in the flight guidance control panel 
(FGCP), in accordance with the paragraphs 3., 3.A., and 3.B. of the 
Accomplishment Instructions of McDonnell Douglas Service Bulletin 
MD80-22-122, dated August 6, 1996 (for Model DC-9-80 series 
airplanes and Model MD-88 airplanes); and McDonnell Douglas Service 
Bulletin MD90-22-005, dated August 6, 1996 (for Model MD-90 
airplanes). Once these actions are completed, the AFM revision 
required by paragraphs (a) and (b) of this AD may be removed.

    Note 2: The McDonnell Douglas service bulletins referenced in 
this paragraph refer to Honeywell Incorporated Service Bulletin 
4034242-22-13 for additional service instructions.

    (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, 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.

    (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.
    (f) The actions shall be done in accordance with McDonnell 
Douglas Service Bulletin MD80-22-122, dated August 6, 1996 (for 
Model DC-9-80 series airplanes and Model MD-88 airplanes); and 
McDonnell Douglas Service Bulletin MD90-22-005, dated August 6, 1996 
(for Model MD-90 airplanes). 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, 3855 Lakewood Boulevard, Long Beach, 
California 90846, Attention: Technical Publications Business 
Administration, Department 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.
    (g) This amendment becomes effective on March 28, 1997.

    Issued in Renton, Washington, on February 10, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-3844 Filed 2-20-97; 8:45 am]
BILLING CODE 4910-13-U