[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