[Federal Register Volume 66, Number 160 (Friday, August 17, 2001)]
[Proposed Rules]
[Pages 43124-43126]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-20808]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-208-AD]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F.28 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 all Fokker Model F.28 series 
airplanes. This proposal would require replacing the main landing gear 
(MLG) torque link dampers with modified and reidentified dampers. This 
action is necessary to prevent degradation of the dampers, which could 
result in MLG high amplitude oscillation in a lateral torsional mode, 
and consequent MLG damage or separation of the MLG from the airplane. 
This action is intended to address the identified unsafe condition.

DATES: Comments must be received by September 17, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-208-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. Comments may be submitted via fax to (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-208-AD'' in the subject line and need not 
be submitted in triplicate. Comments sent via the Internet as attached 
electronic files must be formatted in Microsoft Word 97 for Windows or 
ASCII text.
    The service information referenced in the proposed rule may be 
obtained from Fokker Services B.V., P.O. Box 231, 2150 AE Nieuw-Vennep, 
the Netherlands. This information may be examined at the FAA, Transport 
Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Dan Rodina, Aerospace Engineer, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2125; fax (425) 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 action may be changed in 
light of the comments received.
    Submit comments using the following format:
     Organize comments issue-by-issue. For example, discuss a 
request to change the compliance time and a request to change the 
service bulletin reference as two separate issues.
     For each issue, state what specific change to the proposed 
AD is being requested.
     Include justification (e.g., reasons or data) for each 
request.
    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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2001-NM-208-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,

[[Page 43125]]

ANM-114, Attention: Rules Docket No. 2001-NM-208-AD, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056.

Discussion

    The Rijksluchtvaartdienst (RLD), which is the airworthiness 
authority for the Netherlands, notified the FAA that an unsafe 
condition may exist on all Fokker Model F.28 series airplanes. The RLD 
advises that it has received a report of an incident involving a main 
landing gear (MLG) separation after landing on a Fokker F.28 Mark 0100 
series airplane. Investigation revealed that performance degradation of 
a damper resulted in loss of damping capability. Further investigation 
revealed that the degradation was due to a combination of damper 
anomalies, i.e., a broken retainer ring, and a shim between housing and 
the cap, which was too thick. However, performance degradation of 
dampers is not detectable during normal operations. Such performance 
degradation of a damper, if not corrected, could result in MLG high 
amplitude oscillation in a lateral torsional mode, and consequent MLG 
damage or separation of the MLG from the airplane.

Explanation of Relevant Service Information

    Fokker Services B.V. has issued Fokker Service Bulletin SBF28/32-
157 (for Model F.28 Mark 1000 through 4000 series airplanes) and Fokker 
Service Bulletin SBF100-32-114 (for Model F.28 Mark 0070/0100 series 
airplanes), both dated October 1, 1999, which describe procedures for 
replacing MLG torque link dampers having part number (P/N) 23700-1 or -
3 with modified and reidentified dampers having P/N 23700-5. Dampers 
having P/N 23700-5 have stronger retainers to achieve an improved 
fatigue life, modified poppet springs for improved performance, and 
deletion of shims between housing and cap and increased torque value on 
assembly nuts, to ensure proper damping characteristics. Accomplishment 
of the actions specified in the service bulletins is intended to 
adequately address the identified unsafe condition. The RLD classified 
these service bulletins as mandatory and issued Dutch airworthiness 
directive 1999-138, dated October 29, 1999, in order to assure the 
continued airworthiness of these airplanes in the Netherlands.

FAA's Conclusions

    These airplane models are manufactured in the Netherlands and are 
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 this type design that are 
certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

    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 accomplishment of 
the actions specified in the service bulletin described previously.

Cost Impact

    The FAA estimates that 147 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 6 work 
hours per airplane to accomplish the proposed replacement, and that the 
average labor rate is $60 per work hour. Required parts would cost 
approximately $1,910 per airplane. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be 
$333,690, or $2,270 per airplane.
    The 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 proposed AD were not adopted. The cost impact 
figures discussed in AD rulemaking actions represent only the time 
necessary to perform the specific actions actually required by the AD. 
These figures typically do not include incidental costs, such as the 
time required to gain access and close up, planning time, or time 
necessitated by other administrative actions.

Regulatory Impact

    The regulations proposed herein would not have a substantial direct 
effect 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, it 
is determined that this proposal would not have federalism implications 
under Executive Order 13132.
    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), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Fokker Services B.V.: Docket 2001-NM-208-AD.

    Applicability: All Model F.28 series airplanes, 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 request approval for an 
alternative method of compliance in accordance with paragraph (c) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent separation of the main landing gear (MLG) from the 
airplane, due to performance degradation of the torque link damper; 
accomplish the following:

[[Page 43126]]

Modification and Reidentification

    (a) Replace MLG torque link dampers having part numbers (P/N) 
23700-1 or -3 with dampers having P/N 23700-5, in accordance with 
the Accomplishment Instructions of Fokker Services SBF28/32-157 (for 
Models F.28 Mark 1000 through 4000 series airplanes) and Fokker 
Service Bulletin SBF100-32-114 (for Model F.28 Mark 0070/0100 series 
airplanes), both dated October 1, 1999, as applicable; at the times 
specified in the following table:

                                           Table 1.--Compliance Times
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    Fokker F.28 model (mark)                                                       Compliance required after the
          designation              MLG manufactured by        MLG mod. status        effective date of this AD
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Mk.0100........................  Dowty Aerospace; MD....  Pre-Mod SB F100-32-50..  Within 15 months.
Mk.0100........................  Dowty Aerospace; MD....  Post-Mod SB F100-32-50.  Within 21 months.
Mk.0100........................  Menasco Aerospace......  [Reserved].............  Within 24 months.
Mk.0070........................  Menasco Aerospace......  [Reserved].............  Within 24 months.
Mk.1000 through Mk.4000 series.  Dowty Aerospace; MD....  [Reserved].............  Within 24 months.
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Spares

    (b) As of the effective date of this AD, no person shall install 
torque link damper having P/N 23700-1 or -3, on any airplane.

Alternative Methods of Compliance

    (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, International Branch, ANM-116, 
Transport Airplane Directorate, FAA. Operators shall submit their 
requests through an appropriate FAA Principal Maintenance Inspector, 
who may add comments and then send it to the Manager, International 
Branch, ANM-116.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

Special Flight Permits

    (d) 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.

    Note 3: The subject of this AD is addressed in Dutch 
airworthiness directive 1999-138, dated October 29, 1999.


    Issued in Renton, Washington, on August 13, 2001.
Vi L. Lipski,
Manager, Transport Airplane Directorate,Aircraft Certification Service.
[FR Doc. 01-20808 Filed 8-16-01; 8:45 am]
BILLING CODE 4910-13-P