[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