[Federal Register Volume 61, Number 179 (Friday, September 13, 1996)]
[Proposed Rules]
[Pages 48439-48441]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23442]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-88-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 all Fokker Model F27 Mark 100,
200, 300, 400, 500, 600, and 700 series airplanes. This proposal would
require an inspection to detect cracking of the torque tube assembly of
the left-hand (LH) elevator and surrounding structure; and to detect
loose or sheared rivets in that assembly. It would also require either
replacement or repair of discrepant parts, as appropriate. This
proposal is prompted by a report of fatigue cracking found on the
torque tube support of the LH elevator. The actions specified by the
proposed AD are intended to ensure that cracking is detected and
corrected in a timely manner so as to prevent failure of the torque
tube or its support structure, which could result in reduced
controllability of the airplane.
DATES: Comments must be received by October 24, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-88-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 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-88-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-88-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Rijksluchtvaartdienst (RLD), which is the airworthiness
authority for the Netherlands, recently notified the FAA that an unsafe
condition may exist on all Fokker Model F27 Mark 100, 200, 300, 400,
500, 600, and 700 series airplanes. The RLD advises that it has
received a report of fatigue cracking of the torque tube support of the
left-hand (LH) elevator on one of these airplanes. That airplane had
accumulated 61,200 total landings.
The fatigue cracking of the torque tube on the left-hand side
appears to be caused by heavy vibration due to the propeller wake.
Cracking, and subsequent failure of the torque tube of the LH elevator
and/or its support structures, if not corrected, could result in
reduced controllability of the airplane.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin F27/55-66, dated December 21,
1994, which describes procedures for a one-time inspection to detect
cracking of the left-hand (LH) elevator torque tube and its surrounding
structure. It also describes procedures for a one-time inspection to
detect loose or sheared rivets of that torque tube. The service
bulletin also contains procedures for either replacing or repairing any
discrepancy found. The RLD classified this service bulletin as
mandatory and issued Netherlands airworthiness directive BLA 1995-
007(A), dated January 31, 1995, 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.
[[Page 48440]]
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 a one-time
inspection to detect fatigue cracking of the torque tube of the LH
elevator and its surrounding structure, and repair, if necessary. This
proposed AD also would require an inspection to detect loose or sheared
rivets of the same torque tube assembly, and replacement with
serviceable rivets, if necessary. The actions would be required to be
accomplished in accordance with the service bulletin described
previously.
Interim Action
This is considered interim action until final action is identified,
at which time the FAA may consider further rulemaking.
Other Relevant Rulemaking
Similar cracking of the torque tube previously was reported to be
found on only the right-hand elevator. The FAA has mandated inspections
to detect cracking of that area by means of AD 96-13-07, amendment 39-
9675 (61 FR 34718, July 3, 1996), through the F27 Structural Inspection
Program.
Cost Impact
The FAA estimates that 34 Fokker Model F27 Mark 100, 200, 300, 400,
500, 600, and 700 series airplanes of U.S. registry would be affected
by this proposed AD, that it would take approximately 4 work hours per
airplane to accomplish the proposed actions, 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 $8,160, or $240
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.
Should an operator be required to replace the torque tube assembly
of the LH elevator, the FAA estimates that it would take approximately
2 work hours per airplane to accomplish, and that the average labor
rate is $60 per work hour. Replacement of the assembly would cost
approximately $1,500 per airplane. Based on these figures, the cost
impact of the replacement is estimated to be $1,620 per airplane.
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-88-AD.
Applicability: All Model F27 Mark 100, 200, 300, 400, 500, 600,
and 700 series airplanes, 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 (d) 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 ensure that cracking is detected and corrected in a timely
manner so as to prevent failure of the torque tube of the left-hand
elevator or its support structure, which could result in reduced
controllability of the airplane, accomplish the following:
(a) Prior to the accumulation of 45,000 total flight cycles, or
within 4 months after the effective date of this AD, whichever
occurs later, perform an inspection to detect cracking of the torque
tube assembly and the surrounding structure of the left-hand (LH)
elevator, and to detect any loose or sheared rivets of that
assembly, in accordance with ``Part 1'' of the Accomplishment
Instructions of Fokker Service Bulletin F27/55-66, dated December
21, 1994.
(b) If no cracking is detected, and if no loose or sheared rivet
is detected, during the inspection required by paragraph (a) of this
AD: No further action is required by this AD.
(c) If any discrepancy is detected during the inspection
required by paragraph (a) of this AD: Accomplish the applicable
requirements of paragraphs (c)(1), (c)(2), or (c)(3) of this AD at
the time specified in that paragraph, and in accordance with Fokker
Service Bulletin F27/55-66, dated December 21, 1994.
(1) If any cracking of the torque tube is detected, or if any
loose or sheared rivet is detected: Prior to further flight, replace
the discrepant part(s) in accordance with ``Part 2,'' paragraph A.,
of the Accomplishment Instructions of the service bulletin.
Note 2: Fokker Service Bulletin F27/55-66 references Fokker
Service Bulletin F27/55-40 as an additional source of service
information for procedures to replace the torque tube assembly with
a serviceable assembly.
(2) If any cracking of the rib at station 300 is detected: Prior
to further flight, repair in accordance with ``Part 2,'' paragraph
B., of the Accomplishment Instructions of the service bulletin.
(3) If any cracking in the torque tube support is detected:
Prior to further flight, accomplish the requirements of either
paragraph (c)(3)(i) or (c)(3)(ii) of this AD, as applicable.
(i) If the crack length does not exceed 30 mm, stop drill the
crack and, thereafter, repeat the inspection specified in paragraph
(a) of this AD at intervals not to exceed 50 flight hours, in
accordance with ``Part 2,'' paragraph C, of the Accomplishment
Instructions of the service bulletin.
(ii) If the crack length exceeds 30 mm, repair in accordance
with a method approved by the Manager, Standardization Branch, ANM-
113, FAA, Transport Airplane Directorate.
(d) 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.
Operators shall submit their requests through
[[Page 48441]]
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.
(e) 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 September 6, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-23442 Filed 9-12-96; 8:45 am]
BILLING CODE 4910-13-U
