[Federal Register Volume 59, Number 39 (Monday, February 28, 1994)]
[Unknown Section]
[Page ]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-4450]


[Federal Register: February 28, 1994]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 93-NM-197-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 
cracks of certain demountable flange (inboard) wheel subassemblies and 
of the bolt bosses on certain demountable flange (outboard) wheel 
subassemblies, and modification or replacement, if necessary. This 
proposal is prompted by reports of cracks and broken spokes found on 
certain main wheel assemblies of these airplanes. The actions specified 
by the proposed AD are intended to prevent loss of a main wheel 
assembly during takeoff or landing.

DATES: Comments must be received by April 25, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 93-NM-197-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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) 227-1320.

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 93-NM-197-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. 93-NM-197-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 several operators of Model F28 Mark 
0100 series airplanes have reported finding cracks and broken spokes on 
certain main wheel assemblies, part number 5008131-4. Investigation 
revealed that the manufacturer of these wheels had discontinued a shot-
peening procedure that was part of the manufacturing process prior to 
April 1991. Subsequently, an improved shot-peening procedure on the 
mating surfaces of the inboard wheel subassemblies was introduced in 
October 1992. However, this procedure was not introduced on the 
outboard wheel subassemblies until February 1993. Consequently, a 
number of units were produced that are prone to fretting and cracking 
due to a lack of shot-peening of the assembly mating surfaces and bolt 
bosses. This condition, if not corrected, could result in loss of a 
main wheel assembly during takeoff or landing.
    Fokker has issued Service Bulletins SBF100-32-070, dated January 
18, 1993, and SBF100-32-073, dated September 10, 1993, which reference 
Aircraft Braking Systems Corporation (ABSC) Service Bulletins Fo100-32-
46, dated December 24, 1992, and Fo100-32-48, dated March 10, 1993, as 
the appropriate sources of service information. The RLD classified 
these Fokker service bulletins as mandatory and issued Netherlands 
Airworthiness Directive (BLA) 93-009/3 (A), dated June 1, 1993, in 
order to assure the continued airworthiness of these airplanes in the 
Netherlands.
    ABSC Service Bulletin Fo100-32-46 describes procedures for eddy 
current inspections to detect cracks of certain demountable flange 
(inboard) wheel subassemblies; and, if no cracks are found, 
modification and subsequent inspections of the subassemblies; and, if 
cracks are found, replacement of the subassemblies with serviceable 
parts.
    ABSC Service Bulletin Fo100-32-48 describes procedures for eddy 
current inspections to detect cracks of the bolt bosses of certain 
demountable flange (outboard) wheel subassemblies; and, if no cracks 
are found, modification of the subassemblies; and, if cracks are found, 
replacement of the subassemblies with serviceable parts.
    This airplane model is manufactured in the Netherlands and is type 
certificated for operation in the United States under the provisions of 
Sec. 21.29 of the Federal Aviation Regulations 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 repetitive eddy 
current inspections to detect cracks of certain demountable flange 
(inboard) wheel subassemblies and of the bolt bosses of certain 
demountable flange (outboard) wheel subassemblies, and modification or 
replacement, if necessary. Replacement of a cracked wheel subassembly 
terminates certain repetitive inspections required by this AD. The 
actions would be required to be accomplished in accordance with the 
ABSC service bulletins described previously.
    The FAA estimates that 87 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 14 work 
hours per airplane to accomplish the proposed inspection and 
modification, and that the average labor rate is $55 per work hour. 
Based on these figures, the total cost impact of the proposed AD on 
U.S. operators is estimated to be $66,990, or $770 per airplane. This 
total cost figure assumes that no operator has yet accomplished the 
proposed requirements of this AD action.
    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 14 
CFR part 39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES-

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Fokker: Docket 93-NM-197-AD.

    Applicability: Model F28 Mark 0100 series airplanes equipped 
with Aircraft Braking Systems Corporation (ABSC) main wheel 
assembly, part number 5008131-4, serial numbers APR91-0570 through 
FEB93-0965 inclusive; certificated in any category.
    Compliance: Required as indicated, unless accomplished 
previously. To prevent loss of a main wheel assembly during takeoff 
or landing, accomplish the following:
    (a) For airplanes equipped with a demountable flange (inboard) 
wheel subassembly, part number 5008142-4, serial numbers APR91-0570 
through OCT92-0858 inclusive, or S-APR91-0097 through S-MAY92-0126 
inclusive: Within 100 landings after the effective date of this AD, 
or at the next tire change, whichever occurs first, perform an eddy 
current inspection to detect cracks of the wheel subassembly, in 
accordance with paragraph C. of Section II--Accomplishment 
Instructions of ABSC Service Bulletin Fo100-32-46, dated December 
24, 1992. Repeat this inspection thereafter at intervals not to 
exceed 500 landings or at each tire change, whichever occurs first.
    (1) If no crack is found during any inspection required by 
paragraph (a) of this AD: Prior to further flight following the 
third inspection, modify the wheel subassembly in accordance with 
paragraph D. of Section II--Accomplishments Instructions of the 
service bulletin. After modification, continue to inspect in 
accordance with paragraph (a) of this AD. If no crack is found 
during the first two inspections conducted after modification, no 
further action is required by this paragraph.
    (2) If any crack is found during any inspection required by 
paragraph (a) of this AD, prior to further flight, replace the wheel 
subassembly, part number 5008142-4, with a serviceable part. Such 
replacement constitutes terminating action for the repetitive 
inspections required by paragraph (a) of this AD.
    (b) For airplanes equipped with a demountable flange (outboard) 
wheel subassembly, part number 5008140-1, serial numbers APR91-0570 
through FEB93-0965 inclusive, or S-MAR91-0002 through S-FEB93-0010 
inclusive: Within 100 landings after the effective date of this AD, 
or at the next tire change, whichever occurs first, perform an eddy 
current inspection to detect cracks of the bolt bosses of the wheel 
subassembly, in accordance with paragraph B. of Section II--
Accomplishment Instructions of ABSC Service Bulletin Fo100-32-48, 
dated March 10, 1993. Repeat this inspection thereafter at interals 
not to exceed 500 landings or at each tire change, whichever occurs 
first.
    (1) If no crack is found during any inspection required by 
paragraph (b) of this AD: Prior to further flight following the 
third inspection, modify the wheel subassembly in accordance with 
paragraph C. of Section II--Accomplishment Instructions of the 
service bulletin. Such modification constitutes terminating action 
for the repetitive inspections required by paragraph (b) of this AD.
    (2) If any crack is found during any inspection required by 
paragraph (b) of this AD, prior to further flight, replace the wheel 
subassembly, part number 5008140-1, with a serviceable part. Such 
replacement constitutes terminating action for the repetitive 
inspections required by paragraph (b) of this AD.
    (c) After the effective date of this AD, no person shall install 
any of the following parts on any airplane unless that part has been 
inspected and modified in accordance with paragraph (a) and/or (b) 
of this AD, as applicable.
    (1) ABSC demountable flange (inboard) wheel subassembly, part 
number 5008142-4, having serial numbers APR91-0570 through OCT92-
0858 inclusive, or S-APR91-0097 through S-MAY92-0126 inclusive;
    (2) ABSC demountable flange (outboard) wheel subassembly, part 
number 5008140-1, having serial numbers APR91-0570 through FEB93-
0965 inclusive, or S-MAR91-0002 through S-FEB93-0010 inclusive;
    (3) Main wheel assembly, part number 5008131-4, having serial 
numbers APR91-0570 through FEB 93-0965 inclusive.
    (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, 
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: 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 
Federal Aviation Regulations (FAR) 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 22, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-4450 Filed 2-25-94; 8:45 am]
BILLING CODE 4910-13-U