[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