[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
