AD Amdt-39-10769

[Federal Register Volume 63, Number 182 (Monday, September 21, 1998)]
[Rules and Regulations]
[Pages 50130-50132]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 98-24902]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-28-AD; Amendment 39-10769; AD 98-20-03]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000, 
3000, and 4000 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all Fokker Model F.28 Mark 1000, 2000, 3000, and 4000 
series airplanes, that requires 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 AD also 
requires installation of new MLG torque link dampers, which constitutes 
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 amendment is prompted by 
issuance of mandatory continuing airworthiness information by a foreign 
civil airworthiness authority. The actions specified by this 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: Effective October 26, 1998.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of October 26, 1998.

ADDRESSES: The service information referenced in this AD 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 Federal Aviation Administration (FAA), Transport 
Airplane Directorate, Rules Docket, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North Capitol 
Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all Fokker Model F.28 Mark 1000, 
2000, 3000, and 4000 series airplanes was published in the Federal 
Register on April 2, 1998 (63 FR 16177). That action proposed to 
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. That action also proposed to 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.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request That Final Rule Not Be Issued

    The single commenter, an operator, states that the requirements of 
the proposed rule are unnecessary. The commenter states that the 
incident that initiated the Dutch airworthiness directive was caused by 
certain operators' failure to adequately maintain their landing gear, 
wheels, brakes, and tires. The commenter further notes that 
accomplishment of the proposed installation of a shimmy damper could 
allow airlines to lengthen the time between replacement and repair of 
those worn parts, which would exacerbate the

[[Page 50131]]

condition. The commenter concludes that the requirements of the 
proposed rule would unfairly penalize operators who have adequately 
maintained their airplanes and have no problems with vibration.
    The FAA does not concur that the requirements of this AD are 
unnecessary. As explained in the preamble of the proposed rule, the 
Dutch airworthiness authority [Rijksluchtvaartdienst (RLD)] advised the 
FAA that it received numerous reports of MLG torque link failure 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, or nitrogen or tire pressure that 
is too high. Such deficiencies caused reduced natural stability of the 
MLG in a lateral and torsional mode during landing, resulting in 
vibration and consequent failure of the MLG torque links.
    Although the deficiencies are maintenance-related, the FAA 
considers that the large number of deficiencies reported is sufficient 
evidence that an unsafe condition exists. Therefore, this AD action 
addresses certain identified deficiencies that may result in an unsafe 
condition (reduced controllability of the airplane on the ground during 
takeoff or landing), and requires corrective action, if necessary.

Request for Approval of Alternative Method of Compliance

    The commenter also requests approval of an alternative method of 
compliance that consists of an enhanced maintenance program for landing 
gear components. The commenter provided correspondence indicating that 
Transport Canada Aviation (the airworthiness authority for Canada) has 
approved the commenter's request for an alternative method of 
compliance based on the enhanced maintenance program.
    The FAA does not concur that this final rule should be revised to 
reflect approval of an alternative method of compliance. The 
information submitted by the commenter is insufficient for the FAA to 
evaluate the commenter's suggestion. However, under the provisions of 
paragraph (d) of this final rule, the FAA may consider requests for 
approval of an alternative method of compliance if sufficient data are 
submitted to substantiate that such a design change would provide an 
acceptable level of safety.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule as proposed.

Cost Impact

    The FAA estimates that 27 airplanes of U.S. registry will be 
affected by this AD. It will take approximately 3 work hours per 
airplane to accomplish the required inspections, at an average labor 
rate of $60 per work hour. Based on these figures, the cost impact of 
the inspections required by this AD on U.S. operators is estimated to 
be $4,860, or $180 per airplane, per inspection cycle.
    It will take approximately 18 work hours per airplane to accomplish 
the required installation/modification, at an average labor rate of $60 
per work hour. Required parts will cost approximately $90,000 per 
airplane. Based on these figures, the cost impact of the installation/
modification required 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 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 adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

98-20-03  Fokker Services B.V.: Amendment 39-10769. 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 AD.


[[Page 50132]]


    (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 AD.

    (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.
    (f) The actions shall be done in accordance with Fokker Service 
Bulletin F28/32-151, Revision 1, dated March 12, 1997, which 
includes the following list of effective pages:

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                                    Revision level                      
            Page No.                shown on page     Date shown on page
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1-6, 10........................  1..................  March 12, 1997.   
7-9, 11-13.....................  Original...........  August 9, 1996.   
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This incorporation by reference was approved by the Director of the 
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Copies may be obtained from Fokker Services B.V., Technical Support 
Department, P.O. Box 75047, 1117 ZN Schiphol Airport, the Netherlands. 
Copies may be inspected at the FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington; or at the Office of the 
Federal Register, 800 North Capitol Street, NW., suite 700, Washington, 
DC.

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

    (g) This amendment becomes effective on October 26, 1998.

    Issued in Renton, Washington, on September 11, 1998.
Dorenda D. Baker,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-24902 Filed 9-18-98; 8:45 am]
BILLING CODE 4910-13-U