[Federal Register Volume 61, Number 30 (Tuesday, February 13, 1996)]
[Proposed Rules]
[Pages 5524-5526]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3151]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-59-AD]


Airworthiness Directives; Fokker Model F28 Mark 0100 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 certain Fokker Model F28 Mark 0100 
series airplanes. This proposal would require inspections to detect 
cracking of the Hi-lok bolt holes in the main hinge fittings of the 
horizontal stabilizer, and repair, if necessary. The proposed AD also 
would require modification of the main hinge fitting, modification or 
replacement of rib connecting angles, and modification of ribs. This 
proposal is prompted by a report that cracking was found in the main 
hinge fittings of the horizontal stabilizer during fatigue testing. The 
cracking was a result of higher-than-anticipated loads induced during 
operation of the thrust reverser. The actions specified by the proposed 
AD are intended to prevent 

[[Page 5525]]
deterioration of the fatigue life of the main hinge fittings of the 
horizontal stabilizer and reduced structural integrity of the 
horizontal stabilizer due to higher induced loads.

DATES: Comments must be received by March 25, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-59-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: Tim Dulin, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2141; 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 95-NM-59-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. 95-NM-59-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 certain Fokker Model F28 Mark 0100 series 
airplanes. The RLD advises that it received a report indicating that, 
during full-scale fatigue tests of a Model F28 Mark 0100 test article, 
cracking was found in the flanges of the left and right-hand main hinge 
fittings of the horizontal stabilizer. Such cracking is attributed to 
higher than anticipated loads on the horizontal stabilizer during 
operation of the thrust reverser. This condition, if not corrected, 
could result in a deteriorated fatigue life of the main hinge fittings 
of the horizontal stabilizer, and reduced structural integrity of the 
horizontal stabilizer.
    Fokker has issued Service Bulletin SBF100-55-021, Revision 2, dated 
December 27, 1993, which describes procedures for a rotor probe 
inspection and a pencil probe inspection to detect cracking of the Hi-
lok bolt holes in the main hinge fittings of the horizontal stabilizer. 
For airplanes on which either no cracking or cracking within specified 
limits is found, the service bulletin describes procedures for the 
following:
    1. Modification of the main hinge fittings on the horizontal 
stabilizer and modification or replacement of the connecting angles at 
Rib 215; and
    2. Modification of Rib 215 of the horizontal stabilizer to close 
the lightening holes.
    These modifications entail modifying the Hi-lok bolt holes by cold 
expansion, and stiffening the ribs at Station 215. Accomplishment of 
these modifications will increase the fatigue life of the main hinge 
fittings.
    The RLD classified this Fokker service bulletin as mandatory and 
issued Netherlands airworthiness directive BLA 93-137/2 (A), dated 
February 21, 1994, in order to assure the continued airworthiness of 
these airplanes in the Netherlands.
    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.
    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 rotor probe 
inspection and a pencil probe inspection to detect cracks of the Hi-lok 
bolt holes in the main hinge fittings of the horizontal stabilizer for. 
For certain airplanes, the proposed AD also would require modification 
of the Hi-lok bolt holes by cold expansion and stiffening of the ribs 
at Station 215. The inspections and modification would be required to 
be accomplished in accordance with the service bulletin described 
previously. For certain other airplanes, the proposed AD would require 
the correction of certain cracking found, in accordance with a method 
approved by the FAA.
    The FAA estimates that 90 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 136 work 
hours per airplane to accomplish the proposed actions, and that the 
average labor rate is $60 per work hour. Required parts would cost 
approximately $1,800 per airplane. Based on these figures, the cost 
impact of the proposed AD on U.S. operators is estimated to be 
$896,400, or $9,960 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.
    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 

[[Page 5526]]
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 95-NM-59-AD.

    Applicability: Model F28 Mark 0100 airplanes; having serial 
numbers 11244 through 11420 inclusive, 11422, 11424 through 11428 
inclusive, 11432 through 11439 inclusive, and 11443 through 11445 
inclusive; certificated in any category.

    Note 1: This AD applies to each airplane identified in the 
preceding applicability provision, regardless of whether it has been 
otherwise 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 prevent reduced structural integrity of the horizontal 
stabilizer, accomplish the following:

    Note 2: Inspections and modifications accomplished prior to the 
effective date of this amendment in accordance with Fokker Service 
Bulletin SBF100-55-021, Revision 1, dated September 6, 1993, are 
considered acceptable for compliance with the inspections and 
modifications required by this amendment.

    (a) Prior to the accumulation of 15,000 total flight cycles, or 
within 1 year after the effective date of this AD, whichever occurs 
later: Perform a rotor probe inspection and a pencil probe 
inspection to detect cracking of the Hi-lok bolt holes in the main 
hinge fittings of the horizontal stabilizer, in accordance with Part 
5 of the Accomplishment Instructions of Fokker Service Bulletin 
SBF100-55-021, Revision 2, dated December 27, 1993. This inspection 
is not required for airplanes that have been modified as specified 
in paragraph (b) of this AD, provided that the modification is 
accomplished prior to the accumulation of 1,000 total flight cycles.
    (b) Either prior to the accumulation of 1,000 total flight 
cycles; or prior to further flight after the inspection required by 
paragraph (a) of this AD if, as a result of that inspection, no 
cracking is found, or all cracks that are found are less than or 
equal to the values specified in the Decision Diagram (Figure 2) of 
Fokker Service Bulletin SBF100-55-021, Revision 2, dated December 
27, 1993: Accomplish the modification requirements specified in 
paragraph (b)(1) and (b)(2) of this AD.
    (1) Modify the main hinge fittings of the horizontal stabilizer; 
and replace or modify the connecting angles at Rib 215, as 
applicable; in accordance with Fokker Service Bulletin SBF100-55-
021, Revision 2, dated December 27, 1993, and as specified in either 
paragraph (b)(1)(i) or (b)(1)(ii) of this AD, as applicable.
    (i) For airplanes that have accumulated less than 1,000 total 
flight cycles at the time of modification: Accomplish the 
modification in accordance with either Part 3 or Part 4 of the 
Accomplishment Instructions of the service bulletin, as applicable.
    (ii) For airplanes that have accumulated 1,000 or more total 
flight cycles at the time of modification: Accomplish the 
modification in accordance with either Part 6 or Part 7 of the 
Accomplishment Instructions of the service bulletin, as applicable.
    (2) Modify Rib 215 of the horizontal stabilizer to close the 
lightening holes in accordance with Part 8 of the Accomplishment 
Instructions of Fokker Service Bulletin SBF100-55-021, Revision 2, 
dated December 27, 1993.
    (c) If any cracking is found as a result of the inspection 
required by paragraph (a) of this AD, and the cracking exceeds the 
values specified in the Decision Diagram (Figure 2) of Fokker 
Service Bulletin SBF100-55-021, Revision 2, dated December 27, 1993: 
Prior to further flight, 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 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 February 7, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-3151 Filed 2-12-96; 8:45 am]
BILLING CODE 4910-13-P