[Federal Register Volume 60, Number 199 (Monday, October 16, 1995)]
[Proposed Rules]
[Pages 53552-53554]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-25604]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-87-AD]
Airworthiness Directives; Fokker Model F28 Mark 1000, 2000, 3000,
and 4000 Series Airplanes, and 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
1000, 2000, 3000, and 4000 series airplanes, and Model F28 Mark 0100
series airplanes. This proposal would require repetitive pre-load
adjustment of the main landing gear (MLG) downlock-actuator. This
proposal is prompted by reports that upon landing, the MLG had
collapsed, as a result of the lock toggle-links being pulled out of the
over-center position by the downlock-actuator due to the relative
movement of the upper and lower side-stay members. The actions
specified by the proposed AD are intended to prevent collapse of the
MLG, which could adversely affect the controllability of the airplane
during landing.
DATES: Comments must be received by November 27, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-87-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) 227-1149.
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-87-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-87-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 1000, 2000, 3000,
and 4000 series airplanes and Model F28 Mark 0100
[[Page 53553]]
series airplanes. The RLD advises that it has received a report
indicating that, upon landing without any apparent system failures or
component fractures, a Fokker Model F28 Mark 0100 series airplane
experienced the collapse of its right-hand main landing gear (MLG).
Investigation revealed that, under extreme inward side-load conditions,
relative movement of the upper and lower side-stay members occurs. This
may cause the downlock-actuator to pull the lock toggle-link out of the
over-center position, resulting in loss of the downlock function. This
condition could occur in certain situations that are beyond the design
ultimate load landing conditions, such as touching down at large
``crab'' angles. These conditions, if not corrected, could result in
the collapse of the MLG upon landing, which could adversely affect the
controllability of the airplane during landing.
Fokker has issued Service Bulletins SBF100-32-094, dated November
10, 1994, and Revision 1, dated March 15, 1995 (for Model F28 Mark 0100
series airplanes), and F28/32-153 (for Model F28 Mark 1000, 2000, 3000,
and 4000 series airplanes), dated November 10, 1994, which describe
procedures for pre-load adjustment of the MLG downlock-actuator. This
adjustment will effectively counter any pulling forces on the lock
toggle-links and prevent collapse of the MLG due to the lock-toggle
links being pulled out of the over-center position. The RLD classified
these service bulletins as mandatory and issued the Netherlands
airworthiness directive BLA 94-163(A), dated December 12, 1994, in
order to assure the continued airworthiness of these airplanes in the
Netherlands. BLA 94-163(A) also mandates repetitive pre-load
adjustments of the MLG downlock-actuator.
This airplane model is manufactured in the Netherlands and is type
certificated for operation in the United States under the provisions of
section 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 these type designs 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 pre-load
adjustments of the MLG downlock-actuator. The actions would be required
to be accomplished in accordance with the applicable service bulletin
described previously.
The FAA estimates that 162 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 $60 per work hour. Based on these figures, the
total cost impact of the proposed AD on U.S. operators is estimated to
be $77,760, or $480 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. 106(g), 40101, 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Fokker: Docket 95-NM-87-AD.
Applicability: Model F28 Mark 1000, 2000, 3000, and 4000 series
airplanes equipped with Dowty Aerospace main landing gear (MLG)
downlock-actuators, part number (P/N) 200497-004 or 200498-004 (on
which Dowty Service Bulletin 32-17 has not been accomplished); or P/
N 200497-005 or 200498-005 (on which Dowty Service Bulletin 32-17
has been accomplished); and Model F28 Mark 0100 series airplanes
equipped with Dowty Aerospace MLG downlock-actuators, P/N 201218-
005, -006, -007, or -008; 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 use the authority
provided in paragraph (b) of this AD 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 the collapse of the main landing gear (MLG), due to a
lock toggle-link being pulled out of its over-center position by the
MLG downlock-actuator; accomplish the following:
(a) Within 8 months after the effective date of this AD, perform
a pre-load adjustment of the MLG downlock-actuator, in accordance
with Fokker Service Bulletin SBF100-32-094, dated November 10, 1994,
or Revision 1, dated March 15, 1995 (for Model F28 Mark 0100 series
airplanes); or Fokker Service Bulletin F28/32-153, dated November
10, 1994 (for Model F28 Mark 1000, 2000, 3000, and 4000 series
airplanes); as applicable. Repeat the adjustment thereafter at each
scheduled maintenance, installation, or replacement of the MLG
downlock-actuator.
(b) 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
[[Page 53554]]
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.
(c) 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.
Issued in Renton, Washington, on October 10, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-25604 Filed 10-13-95; 8:45 am]
BILLING CODE 4910-13-U
