[Federal Register Volume 62, Number 36 (Monday, February 24, 1997)]
[Rules and Regulations]
[Pages 8156-8157]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4201]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-38-AD; Amendment 39-9941; AD 97-04-16]
RIN 2120-AA64


Airworthiness Directives; Fokker Model F27 Series Airplanes 
Equipped With Walter Kidde Nose Wheel Steering System

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Fokker Model F27 series airplanes, that requires 
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 amendment also requires that periodic 
inspections of that torque value be incorporated into the FAA-approved 
maintenance program. This amendment 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 this 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: Effective March 31, 1997.

    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 31, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, 
Alexandria, Virginia 22314. 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: Ruth 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: 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 certain Fokker Model F27 series 
airplanes was published in the Federal Register on July 29, 1996 (61 FR 
39366). That action proposed to 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).
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Support for the Proposal

    One commenter supports the proposed rule.

Request to Withdraw Proposal

    One commenter, a U.S. operator, requests that the proposal be 
withdrawn because it is unnecessary. The commenter points out that the 
proposed requirements previously were issued by Fokker both as a 
service bulletin and a maintenance circular several years ago. This 
commenter has already added the inspections to its maintenance program, 
far in advance of any requirement by AD to do so. The commenter 
contends that mandating the actions via an AD will ``only add an 
administrative burden on an industry already overburdened with 
administrative tasks, many of which are redundant.'' Instead of issuing 
this AD, the commenter recommends that the proposed requirements be 
added to the airlines' Operations Specifications, or merely have the 
Principal Maintenance Inspectors for the affected airlines talk to the 
operators about this issue. The commenter maintains that handling the 
proposed requirements in some other way than by AD action would save 
the affected operators a considerable amount of time and money.
    The FAA does not concur with the commenter's request to withdraw 
the proposal. The FAA acknowledges that the required actions specified 
in this AD were contained in a manufacturer's service bulletin and 
maintenance circular, both of which were released some time ago. 
Prudent operators, such as the commenter, may have accomplished those 
actions already. However, until an AD is issued, there is no legal 
basis for requiring U.S. operators to comply with those actions. The AD 
is the vehicle for ensuring, by law, that all affected operators 
perform the necessary actions that will address the identified unsafe 
condition. In light of this, the FAA has determined that this AD is 
appropriate and warranted.
    Further, the FAA is not convinced that issuance of this AD will add 
a significant economic or administrative burden on operators who have 
already accomplished the required actions, as the commenter suggests:
    First, the FAA points out that there are currently only 34 U.S.-
registered airplanes that are affected by the AD.
    Second, the compliance provision of the AD clearly states that 
compliance is ``required as indicated, unless accomplished 
previously.'' Therefore, operators who have already accomplished the 
required actions need only make a single entry in their maintenance 
logs to indicate compliance with the AD. Further, once the maintenance 
program is changed to include the required periodic inspections, in 
accordance with paragraph (b) of the AD, operators do not need to make 
a maintenance log entry to show compliance with the AD every time those 
inspections are accomplished thereafter. (A new Note 2 has been added 
to the final rule to specify this.) Such procedures should

[[Page 8157]]

not pose a serious burden on any operator.

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 with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.


Cost Impact

    The FAA estimates that 34 Fokker Model F27 series airplanes of U.S. 
registry will be affected by this AD.
    It will take approximately 2 work hours per airplane to accomplish 
the required actions, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of this 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 requirements of this AD 
action, and that no operator would accomplish those actions in the 
future if this AD were not adopted.
    However, the FAA has been advised that one U.S. operator already 
has accomplished the required actions on its 2 affected airplanes. 
Therefore, the future cost impact of this AD is only $4,056.

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:

97-04-16 Fokker: Amendment 39-9941. 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 inch-pounds, 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.

    Note 2: Once the maintenance program is changed to include the 
required periodic inspections, in accordance with this paragraph, 
operators do not need to make a maintenance log entry to show 
compliance with this AD every time those inspections are 
accomplished thereafter.

    (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 3: 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.
    (e) The actions shall be done in accordance with Fokker Service 
Bulletin F27/32-166, dated September 7, 1993; and Fokker F27 
Maintenance Circular No. 32-6, dated April 30, 1993. 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 Aircraft USA, Inc., 1199 
North Fairfax Street, Alexandria, Virginia 22314. 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.
    (f) This amendment becomes effective on March 31, 1997.

    Issued in Renton, Washington, on February 13, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-4201 Filed 2-21-97; 8:45 am]
BILLING CODE 4910-13-U