[Federal Register Volume 61, Number 146 (Monday, July 29, 1996)]
[Proposed Rules]
[Pages 39366-39367]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-19151]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-38-AD]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F27 Series Airplanes
Equipped With Walter Kidde Nose Wheel Steering System
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 series
airplanes. This proposal would require increasing the torque value of
the bolt that connects the gearbox housing assembly of the steering
unit to the pivot bracket of the nose landing gear (NLG). This proposal
would also require that periodic inspections of that torque value be
incorporated into the FAA-approved maintenance program. This proposal
is prompted by several reports that the dowel pins in the Walter Kidde
nose wheel steering system were found broken and/or had elongated holes
due to a reduced torque value of the subject bolt. The actions
specified by the proposed AD are intended to prevent such a reduction
in the torque value, which could result in failure of the dowel pins in
the Walter Kidde nose wheel steering system; this situation could
result in reduced controllability of the airplane or the collapse of
the NLG during landing.
DATES: Comments must be received by September 9, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-38-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 Aircraft USA, Inc., 1199 North Fairfax Street,
Alexandria, Virginia 22314. This information may be examined at the
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Ruth E. Harder, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-1721; fax (206) 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 96-NM-38-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-103, Attention: Rules
Docket No. 96-NM-38-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Rijksluchtvaartdienst (RLD), which is the airworthiness
authority for the Netherlands, has notified the FAA that an unsafe
condition may exist on certain Fokker Model F27 series airplanes,
equipped with a Walter Kidde nose wheel steering system having part
number 893954. The RLD advises that it has received several reports
indicating that the dowel pins in the Walter Kidde nose wheel steering
system were found broken and/or had elongated holes. Investigation
revealed that the cause of these discrepancies was due to a reduction
of the torque value of the bolt that connects the gearbox housing
assembly of the steering unit to the pivot bracket of the nose landing
gear (NLG). This condition, if not corrected, could result in failure
of the dowel pins; this situation could result in reduced
controllability of the airplane or the collapse of the NLG during
landing.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin F27/32-166, dated September 7,
1993, which describes procedures for increasing the torque value of the
bolt that connects the gearbox housing assembly of the steering unit to
the pivot bracket of the NLG. The RLD classified this service bulletin
as mandatory and issued Dutch airworthiness directive BLA 93-132 (A),
dated September 17, 1993, in order to assure the continued
airworthiness of these airplanes in the Netherlands.
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, the
proposed AD would require increasing the torque value of the bolt that
connects the gearbox housing assembly of the steering unit to the pivot
bracket of the NLG. The actions would be required to be accomplished in
accordance with the service bulletin described previously.
The proposed AD would also require that periodic inspections of the
torque
[[Page 39367]]
value of the affected bolt be incorporated into the FAA-approved
maintenance program.
Cost Impact
The FAA estimates that 34 Fokker Model F27 series airplanes of U.S.
registry would be affected by this proposed AD, that it would take
approximately 2 work hours per airplane to accomplish the proposed
initial tightening of the bolt, and that the average labor rate is $60
per work hour. Based on these figures, the cost impact of the proposed
AD on U.S. operators is estimated to be $4,080, or $120 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.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Fokker: Docket 96-NM-38-AD.
Applicability: Model F27 series airplanes, serial numbers 10102
through 10692 inclusive; equipped with Walter Kidde nose wheel
steering system (steering unit gearbox housing assembly) having part
number 893954; 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 a reduction in the torque value of the bolt in the
Walter Kidde nose wheel steering system, which could result in
reduced controllability of the airplane or the collapse of the nose
landing gear (NLG) during landing, accomplish the following:
(a) Within 500 flight hours after the effective date of this AD,
or within 4 months after the effective date of this AD, whichever
occurs first, tighten the bolt that connects the gearbox housing
assembly of the steering unit to the pivot bracket of the NLG to a
torque value of 700 to 800 pounds per inch, in accordance with
Fokker Service Bulletin F27/32-166, dated September 7, 1993.
(b) Within 30 days following accomplishment of paragraph (a) of
this AD, revise the FAA-approved maintenance program to include
periodic inspections of the torque value of the affected bolt, as
described in Fokker F27 Maintenance Circular No. 32-6, dated April
30, 1993; and, thereafter, comply with those requirements.
(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, Standardization Branch, ANM-113,
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,
Standardization Branch, ANM-113.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(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.
Issued in Renton, Washington, on July 23, 1996.
John J. Hickey,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service. -
[FR Doc. 96-19151 Filed 7-26-96; 8:45 am]
BILLING CODE 4910-13-P
