[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]
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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.
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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
