[Federal Register Volume 59, Number 90 (Wednesday, May 11, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-11353]


[[Page Unknown]]

[Federal Register: May 11, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-38-AD]

 

Airworthiness Directives; Fokker Model F28 Mark 0100 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 
series airplanes. This proposal would require replacement of the 
autopilot disconnect switches with modified units. This proposal is 
prompted by several incidents in which the flight crew did not depress 
both halves of the autopilot disconnect switch during the LAND 2 or 
LAND 3 approach and, as a result, one autopilot remained engaged. This 
condition resulted in unanticipated movements of the stabilizer trim 
and higher than anticipated control forces of the flight controls. The 
actions specified by the proposed AD are intended to prevent the flight 
crew from inadvertently disconnecting only one autopilot when both 
autopilots are engaged, which could result in unanticipated control 
surface movements.

DATES: Comments must be received by June 20, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-38-AD, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9 a.m. and 3 p.m., Monday through Friday, except Federal 
holidays.
    The service information referenced in the proposed rule may be 
obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, 
Alexandria, Virginia 22314. This information may be examined at the 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington.

FOR FURTHER INFORMATION CONTACT: Tim Dulin, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2141; fax (206) 227-1320.

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-38-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-38-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Rijksluchtvaartdienst (RLD), which is the airworthiness 
authority for the Netherlands, recently notified the FAA that an unsafe 
condition may exist on certain Fokker Model F28 Mark 0100 series 
airplanes. The RLD advises that operators have reported several 
incidents in which the flight crew did not depress both halves of the 
autopilot disconnect switch during the LAND 2 or LAND 3 approach and, 
as a result, one autopilot remained engaged. Although certain aural 
warnings sounded and visual indicators illuminated in these situations, 
the flight crew still believed that both autopilots had been 
disconnected. Consequently, unanticipated movements of the stabilizer 
trim and higher than anticipated control forces of the flight controls 
occurred. Inadvertent disconnection of only one autopilot when both 
autopilots are engaged could result in unanticipated control surface 
movements.
    Fokker has issued Service Bulletin SBF100-22-020, dated September 
25, 1990, that describes procedures for replacement of the autopilot 
disconnect switches with modified units. Installation of the modified 
units will ensure that if one-half of the autopilot disconnect switch 
is depressed, both autopilots will disengage; in addition, the system 
will remain separated. The RLD classified this service bulletin as 
mandatory and issued Netherlands Airworthiness Directive 90-112(A), 
dated October 15, 1990, in order to assure the continued airworthiness 
of these airplanes in the Netherlands.
    This airplane model is manufactured in the Netherlands and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations and the applicable 
bilateral airworthiness agreement. Pursuant to this bilateral 
airworthiness agreement, the RLD has kept the FAA informed of the 
situation described above. The FAA has examined the findings of the 
RLD, reviewed all available information, and determined that AD action 
is necessary for products of this type design that are certificated for 
operation in the United States.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design registered 
in the United States, the proposed AD would require replacement of the 
autopilot disconnect switches with modified units. The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously.
    The FAA estimates that 19 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 8 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $55 per work hour. Required parts would cost 
approximately $2,500 per airplane. Based on these figures, the total 
cost impact of the proposed AD on U.S. operators is estimated to be 
$55,860, or $2,940 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.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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:

Fokker: Docket 94-NM-38-AD.

    Applicability: Model F28 Mark 0100 series airplanes; serial 
numbers 11244 through 11286 inclusive, 11289 through 11293 
inclusive, 11295 through 11297 inclusive, 11300, 11303, 11306, 
11308, 11310, 11312, and 11313; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent the flight crew from inadvertently disconnecting only 
one autopilot when both autopilots are engaged, which could result 
in unanticipated control surface movements, accomplish the 
following:
    (a) Within 6 months after the effective date of this AD, replace 
the autopilot disconnect switches with modified units, in accordance 
with Fokker Service Bulletin SBF100-22-020, dated September 25, 
1990.
    (b) As of 6 months after the effective date of this AD, no 
person shall install an autopilot disconnect switch, part number 
A47007-401 or A47007-403, on any airplane.
    (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, Standardization Branch, ANM-113, 
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, 
Standardization Branch, ANM-113.

    Note: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (d) Special flight permits may be issued in accordance with 
Federal Aviation Regulations (FAR) Sec. 21.197 and Sec. 21.199 to 
operate the airplane to a location where the requirements of this AD 
can be accomplished.

    Issued in Renton, Washington, on May 5, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certificate 
Service.
[FR Doc. 94-11353 Filed 5-10-94; 8:45 am]
BILLING CODE 4910-13-U