[Federal Register Volume 63, Number 63 (Thursday, April 2, 1998)]
[Proposed Rules]
[Pages 16177-16179]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-8707]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-28-AD]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 
3000, and 4000 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 Mark 1000, 
2000, 3000, and 4000 series airplanes. This proposal would require 
repetitive inspections of the center joint of the main landing gear 
(MLG) torque link and the MLG assembly for excessive free-play; and 
correction, if necessary. This proposal would also require installation 
of new MLG torque link dampers, which would constitute terminating 
action for the repetitive inspections; and revision of the FAA-approved 
maintenance program to incorporate inspections and overhaul of the new 
torque link dampers. This proposal is prompted by issuance of mandatory 
continuing airworthiness information by a foreign civil airworthiness 
authority. The actions specified by the proposed AD are intended to 
prevent the failure of MLG torque links, which could result in reduced 
controllability of the airplane on the ground during takeoff or 
landing.

DATES: Comments must be received by May 4, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-28-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 Services B.V., Technical Support Department, P.O. 
Box 75047, 1117 ZN Schiphol Airport, the Netherlands. This information 
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2110; 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

[[Page 16178]]

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 98-NM-28-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-114, Attention: Rules 
Docket No. 98-NM-28-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 numerous reports of main landing gear 
(MLG) torque link failures on in-service airplanes. The cause of these 
failures has been attributed to one or more deficiencies, such as 
excessive play in hinges and bearings, worn or non-approved tires, and 
nitrogen pressure or tire pressure that is too high. These deficiencies 
caused reduced natural stability of the MLG in a lateral and torsional 
mode during landing, vibration, and consequent failure of the MLG 
torque links. These conditions, if not corrected, could result in 
reduced controllability of the airplane on the ground during takeoff or 
landing.

Explanation of Relevant Service Information

    Fokker has issued Service Bulletin F28/32-151, Revision 1, dated 
March 12, 1997, which describes procedures for repetitive visual 
inspections of the center joint of the MLG torque link and of the MLG 
assembly for excessive free-play; and correction, if necessary. The 
service bulletin also describes procedures for installation of new MLG 
torque link dampers, which would eliminate the need for the repetitive 
inspections; and revision of the FAA-approved maintenance program to 
incorporate visual inspections and overhaul of the new torque link 
dampers. Accomplishment of the actions specified in Part 2 of the 
Accomplishment Instructions of the service bulletin is intended to 
adequately address the identified unsafe condition. The RLD classified 
this service bulletin as mandatory and issued Dutch airworthiness 
directive BLA 1996-103(A), dated August 30, 1996, in order to assure 
the continued airworthiness of these airplanes in the Netherlands.
    Parts 1.A., 1.B., 1.C., and 1.D. of the Accomplishment Instructions 
of Fokker Service Bulletin F28/32-151, Revision 1, dated March 12, 
1997, reference Fokker F.28 Airplane Maintenance Manual (AMM), Chapters 
32-10-01, 32-10-00, and 32-10-04, as additional sources of service 
information to accomplish the actions required by this proposal.

FAA's Conclusions

    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 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 27 airplanes of U.S. registry would be 
affected by this proposed AD. It would take approximately 3 work hours 
per airplane to accomplish the proposed inspections, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the inspections proposed by this AD on U.S. operators is 
estimated to be $4,860, or $180 per airplane, per inspection cycle.
    It would take approximately 18 work hours per airplane to 
accomplish the proposed installation/modification, at an average labor 
rate of $60 per work hour. Required parts would cost approximately 
$90,000 per airplane. Based on these figures, the cost impact of the 
installation/modification proposed by this AD on U.S. operators is 
estimated to be $2,459,160, or $91,080 per airplane.
    The cost impact figures discussed above are 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.

Regulatory Impact

    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), 40113, 44701.

[[Page 16179]]

Sec. 39.13  [Amended]

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

Fokker Services B.V.: Docket 98-NM-28-AD.

    Applicability: All Model F.28 Mark 1000, 2000, 3000, and 4000 
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 (d) 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 the failure of main landing gear (MLG) torque links, 
which could result in reduced controllability of the airplane on the 
ground during takeoff or landing, accomplish the following:
    (a) Within 1,000 flight cycles after the effective date of this 
AD, perform a visual inspection of the center joint of the MLG 
torque link for excessive free play, in accordance with Part 1.D. of 
the Accomplishment Instructions of Fokker Service Bulletin F28/32-
151, Revision 1, dated March 12, 1997.
    (1) If no discrepancy is detected, repeat the visual inspection 
thereafter at intervals not to exceed 1,000 flight cycles.
    (2) If any discrepancy is detected, prior to further flight, 
correct the discrepant condition in accordance with Part 1.D. of the 
Accomplishment Instructions of the service bulletin. Repeat the 
visual inspection thereafter at intervals not to exceed 1,000 flight 
cycles.

    Note 2: Part 1.D. of the Accomplishment Instructions of Fokker 
Service Bulletin F28/32-151, Revision 1, dated March 12, 1997, 
references Fokker F.28 Airplane Maintenance Manual (AMM), Chapter 
32-10-04, as an additional source of service information to 
accomplish the actions required by this proposal.

    (b) Within 3,000 flight cycles after the effective date of this 
AD, perform a visual inspection of the MLG assembly for excessive 
free play, in accordance with Parts 1.A., 1.B., and 1.C. of the 
Accomplishment Instructions of Fokker Service Bulletin F28/32-151, 
Revision 1, dated March 12, 1997.
    (1) If no discrepancy is detected, repeat the visual inspection 
thereafter at intervals not to exceed 3,000 flight cycles.
    (2) If any discrepancy is detected, prior to further flight, 
correct the discrepant condition in accordance with Parts 1.A., 
1.B., and/or 1.C. of the Accomplishment Instructions of the service 
bulletin, as applicable. Repeat the visual inspection thereafter at 
intervals not to exceed 3,000 flight cycles.

    Note 3: Parts 1.A., 1.B., and 1.C. of the Accomplishment 
Instructions of Fokker Service Bulletin F28/32-151, Revision 1, 
dated March 12, 1997, reference Fokker F.28 AMM, Chapters 32-10-01, 
32-10-00, and 32-10-04, as additional sources of service information 
to accomplish the actions required by this proposal.

    (c) Within 30 months after the effective date of this AD, 
accomplish paragraphs (c)(1) and (c)(2) of this AD.
    (1) Install torque link dampers and associated sub-assemblies in 
accordance with Part 2 of the Accomplishment Instructions of Fokker 
Service Bulletin F28/32-151, Revision 1, dated March 12, 1997. 
Accomplishment of the installation constitutes terminating action 
for the repetitive inspection requirements of this AD.
    (2) Revise the FAA-approved maintenance program to incorporate a 
visual inspection of the oil level of the torque-link dampers 
thereafter at intervals not to exceed 250 flight hours, and 
incorporate a scheduled overhaul of each damper concurrent with the 
overhaul of the MLG on which it is installed, in accordance with 
Part 2 of the Accomplishment Instructions of Fokker Service Bulletin 
F28/32-151, Revision 1, dated March 12, 1997.

    Note 4: After the maintenance program is revised to include the 
required inspection and overhaul actions in accordance with 
paragraph (c)(2) of this AD, operators do not need to make a 
maintenance log entry to show compliance with this AD each time 
those actions are accomplished thereafter.

    (d) 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, 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, International 
Branch, ANM-116.

    Note 5: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (e) 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 6: The subject of this AD is addressed in Dutch 
airworthiness directive BLA 1996-103(A), dated August 30, 1996.

    Issued in Renton, Washington, on March 27, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-8707 Filed 4-1-98; 8:45 am]
BILLING CODE 4910-13-U