[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
