[Federal Register Volume 63, Number 72 (Wednesday, April 15, 1998)]
[Proposed Rules]
[Pages 18342-18344]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-9875]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

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


Airworthiness Directives; Fokker Model F27 Mark 100, 200, 300, 
400, 500, 600, and 700 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 F27 Mark 100, 
200, 300, 400, 500, 600, and 700 series airplanes. This proposal would 
require replacement of the actuating ram bobbin and O-ring seals of the 
main landing gear (MLG), with new bobbins and improved O-ring seals. 
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 loss 
of dampening of the MLG actuating ram, which could result in failure of 
the MLG lockstruts, and consequent structural damage to the airplane.

DATES: Comments must be received by May 15, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-98-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,

[[Page 18343]]

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 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-98-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-98-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 certain Fokker Model F27 Mark 100, 200, 300, 
400, 500, 600, and 700 series airplanes. The RLD advises that it 
received reports of broken lockstruts on the main landing gear (MLG) 
due to loss of dampening of the MLG actuating ram, which extends and 
retracts the MLG. The actuating ram is equipped with a dampening 
chamber filled with silicon fluid (oil), which is forced through a 
restrictor to dampen gear movement. The existing design of the O-ring 
seals could allow fluid to leak gradually, which may not be noticed 
during regular maintenance inspections, and could lead to loss of 
dampening of the MLG actuating ram. This condition, if not corrected, 
could result in failure of the MLG lockstruts, and consequent 
structural damage to the airplane.

Explanation of Relevant Service Information

    The manufacturer has issued Fokker Service Bulletin F27/32-168, 
dated October 23, 1996, which describes procedures for replacing the 
actuating ram bobbin, O-ring seals, and back-up O-ring seals of the 
MLG, with new bobbins and improved O-ring seals. The service bulletin 
references Dunlop Equipment Division Service Bulletin SB 32-1142, dated 
October 22, 1996, as an additional source of service information to 
accomplish the modification. Accomplishment of the actions specified in 
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 1996-142 (A), dated November 
29, 1996, in order to assure the 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 
actions specified in the service bulletin described previously.

Cost Impact

    The FAA estimates that 34 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 26 work 
hours per airplane to accomplish the proposed replacement, at an 
average labor rate of $60 per work hour. Required parts would be 
furnished by the manufacturer at no cost to the operators. Based on 
these figures, the cost impact of the replacement proposed by this AD 
on U.S. operators is estimated to be $53,040, or $1,560 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 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 18344]]




Sec. 39.13  [Amended]

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

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

    Applicability: Model F27 Mark 100, 200, 300, 400, 500, 600, and 
700 series airplanes; equipped with Dunlop main landing gear (MLG) 
actuating rams having part number (P/N) AC67132, AC67134, AC67848, 
or AC67850; 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 loss of dampening of the MLG actuating ram, which 
could result in failure of the MLG lockstruts, and consequent 
structural damage to the airplane, accomplish the following:
    (a) Within 4,000 flight hours or 2 years after the effective 
date of this AD, whichever occurs first, replace the actuating ram 
bobbin, O-ring seals, and back-up O-ring seals of the MLG, with new 
bobbins and improved O-ring seals, in accordance with Fokker Service 
Bulletin F27/32-168, dated October 23, 1996.

    Note 2: Dunlop Equipment Division Service Bulletin SB 32-1142, 
dated October 22, 1996, and Revision 1, dated January 14, 1997, 
provide service information for accomplishment of the modification.

    (b) As of the effective date of this AD, no person shall install 
on any airplane a Dunlop Main Undercarriage Ram, part number (P/N) 
AC67132, AC67134, AC67848, or AC67850, unless it has been modified 
in accordance with Fokker Service Bulletin F27/32-168, dated October 
23, 1996.
    (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, FAA, 
Transport Airplane Directorate. Operators shall submit their request 
through an appropriate FAA Principal Maintenance Inspector, who may 
add comments and then send it to the Manager, International Branch, 
ANM-116.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (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 4: The subject of this AD is addressed in Dutch 
airworthiness directive 1996-142(A), dated November 29, 1996.

    Issued in Renton, Washington, on April 8, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-9875 Filed 4-14-98; 8:45 am]
BILLING CODE 4910-13-U