[Federal Register Volume 60, Number 52 (Friday, March 17, 1995)]
[Proposed Rules]
[Pages 14395-14397]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-6632]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-02-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 repetitive checks to 
detect backlash in the elevator mechanical control system, and various 
follow-on actions. The proposed AD would also provide for an optional 
terminating action for the repetitive check requirements. This proposal 
is prompted by a report indicating that corrosion was found on the 
pivot bolts and bushings of the backlash remover lever mechanism on the 
elevator booster control unit (BCU) of a Model F28 Mark 0100 series 
airplane. The actions specified by the proposed AD are intended to 
prevent such corrosion, which could result in backlash in the elevator 
controls and reduced elevator control authority in the manual mode.

DATES: Comments must be received by May 12, 1995.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-02-AD, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056. Comments may be inspected at this location 
between 9:00 a.m. and 3:00 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) 227-1100.

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 95-NM-02-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. 95-NM-02-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 all Fokker Model F28 Mark 0100 series airplanes 
equipped with a certain Menasco Aerospace Elevator Booster Control Unit 
(BCU). The RLD advises that corrosion was found on the pivot bolts and 
bushings of the backlash remover lever mechanism on the elevator BCU of 
Model F28 Mark 0100 series airplanes. This mechanism prevents backlash 
in the elevator control forces when the elevator BCU is not 
hydraulically powered, providing the pilot with full manual control of 
the elevator system. Investigation revealed that corrosion on the pivot 
bolts and bushings causes the backlash remover mechanism to stick, 
which results in deteriorated elevator control when the BCU is in 
manual mode. This condition, if not corrected, could result in backlash 
in the elevator controls and reduced elevator control authority in the 
manual mode.
    Fokker has issued Service Bulletin SBF100-27-052, Revision 1, dated 
March 29, 1994, which describes procedures for:
    1. Performing repetitive operational checks to detect backlash in 
the elevator mechanical control system;
    2. Performing an inspection to determine whether certain elevator 
BCU bolts rotate and slide freely, and to detect corrosion on the bolts 
of the backlash remover lever mechanism, if any backlash is detected; 
and
    3. Replacing the elevator BCU or bolts with a serviceable part, if 
any anomaly is detected.
    The RLD classified this service bulletin as mandatory and issued 
Dutch airworthiness directive BLA 93-051/3 (A), dated April 29, 1994, 
in order to assure the continued airworthiness of these airplanes in 
the Netherlands.
    Additionally, Fokker has issued Service Bulletin SBF100-27-061, 
dated March 2, 1994, which provides instructions for accomplishing an 
optional modification of the affected elevator BCU, which would 
eliminate the need for the repetitive operational checks. This 
modification involves replacing two bolts in the elevator BCU with new 
bolts.
    This airplane model is manufactured in the Netherlands and is type 
certificated for operation in the United States under the provisions of 
section [[Page 14396]] 21.29 of the Federal Aviation Regulations (14 
CFR 21.29) 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 repetitive 
operational checks to detect backlash in the elevator mechanical 
control system. The proposed AD would also require performing an 
inspection to determine whether certain elevator BCU bolts rotate and 
slide freely, and to detect corrosion on the bolts of the backlash 
remover lever mechanism, if any backlash is detected; and replacing the 
elevator BCU or bolts with a serviceable part, if any anomaly is 
detected. Additionally, the proposed AD would provide for an optional 
modification of certain elevator BCU's; or replacement of a certain 
elevator BCU with a unit having a certain serial number, which would 
constitute terminating action for the repetitive operational check 
requirements. The actions would be required to be accomplished in 
accordance with the service bulletins described previously. The 
proposed AD would also require performing appropriate trouble-shooting 
procedures, if no anomalies are detected in accordance with the 
Airplane Maintenance Manual.
    As a result of recent communications with the Air Transport 
Association (ATA) of America, the FAA has learned that, in general, 
some operators may misunderstand the legal effect of AD's on airplanes 
that are identified in the applicability provision of the AD, but that 
have been altered or repaired in the area addressed by the AD. The FAA 
points out that all airplanes identified in the applicability provision 
of an AD are legally subject to the AD. If an airplane has been altered 
or repaired in the affected area in such a way as to affect compliance 
with the AD, the owner or operator is required to obtain FAA approval 
for an alternative method of compliance with the AD, in accordance with 
the paragraph of each AD that provides for such approvals. A note has 
been included in this notice to clarify this requirement.
    The FAA estimates that 112 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 1 work 
hour per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would be 
supplied by the manufacturer at no cost to the operators. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $6,720, or $60 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 
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. 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 95-NM-02-AD.

    Applicability: Model F28 Mark 0100 series airplanes; equipped 
with Menasco Aerospace Elevator Booster Control Unit (BCU) having 
part number (P/N) 23400-3 or P/N 23400-5 with serial numbers MC-001 
through MC-288 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 use the authority 
provided in paragraph (e) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition; or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent backlash in the elevator controls and reduced 
elevator control authority in the manual mode, accomplish the 
following:
    (a) Within 500 flight cycles or 60 days after the effective date 
of this AD, whichever occurs first, perform an operational check to 
detect backlash in the elevator mechanical control system, in 
accordance with Part 1 of the Accomplishment Instructions of Fokker 
Service Bulletin SBF100-27-052, Revision 1, dated March 29, 1994. 
Repeat the check thereafter at intervals not to exceed 500 flight 
cycles or 60 days, whichever occurs first.
    (b) If any backlash is detected during any operational check 
required by paragraph (a) of this AD, prior to further flight, 
perform an inspection to determine whether the elevator BCU bolts, 
having part numbers NAS6204C22D and P/N NAS6204C13D, rotate and 
slide freely, and to detect corrosion on the bolts of the backlash 
remover lever mechanism; in accordance with Part 2 of the 
Accomplishment Instructions of Fokker Service Bulletin SBF100-27-
052, Revision 1, dated March 29, 1994.
    (1) If no anomalies are detected, prior to further flight, 
perform appropriate trouble-shooting procedures in accordance with 
the Airplane Maintenance Manual.
    (2) If any anomaly is detected, prior to further flight, replace 
the elevator BCU or bolts, as applicable, with serviceable parts, in 
accordance with the service bulletin.
    (c) Modification of the affected elevator BCU having P/N 23400-3 
or -5, in accordance with Fokker Service Bulletin SBF100-27-061, 
dated March 2, 1994; or replacement of any affected elevator BCU 
having P/N 23400-3 or -5 with a unit having [[Page 14397]] a serial 
number other than MC-001 through MC-288 inclusive, in accordance 
with the Airplane Maintenance Manual; constitutes terminating action 
for the repetitive check requirements of this AD.
    (d) As of the effective date of this AD, no person shall install 
Menasco Aerospace Elevator Booster Control Unit (BCU) having part 
number (P/N) 23400-3 or P/N 23400-5 with serial numbers MC-001 
through MC-288 inclusive on any airplane.
    (e) 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Standardization Branch, ANM-113.

    (f) Special flight permits may be issued in accordance with 
Secs. 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.

    Issued in Renton, Washington, on March 13, 1995.
Neil D. Schalekamp,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-6632 Filed 3-16-95; 8:45 am]
BILLING CODE 4910-13-U