[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
