[Federal Register Volume 59, Number 217 (Thursday, November 10, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-26719]


[[Page Unknown]]

[Federal Register: November 10, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 93-NM-197-AD; Amendment 39-9054; AD 94-22-05]

 

Airworthiness Directives; Fokker Model F28 Mark 0100 Series 
Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to certain Fokker Model F28 Mark 0100 series airplanes, that 
requires 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 of the wheel subassemblies. This amendment is prompted by 
reports of cracks and broken spokes found on certain main wheel 
assemblies of these airplanes. The actions specified by this AD are 
intended to prevent loss of a main wheel assembly during takeoff or 
landing.

DATES: Effective December 12, 1994.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of December 12, 1994.

ADDRESSES: The service information referenced in this AD may be 
obtained from Fokker Aircraft USA, Inc., 1199 North Fairfax Street, 
Alexandria, Virginia 22314. This information may be examined at the 
Federal Aviation Administration (FAA), Transport Airplane Directorate, 
Rules Docket, 1601 Lind Avenue, SW., Renton, Washington; or at the 
Office of the Federal Register, 800 North Capitol Street, NW., suite 
700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 
series airplanes was published in the Federal Register on February 28, 
1994 (59 FR 9450). That action proposed to 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 of the 
wheel subassemblies.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed rule.
    One commenter requests that proposed paragraphs (a) and (b) be 
revised to provide credit for inspections accomplished within the last 
500 landings before the final rule becomes effective. This commenter 
has been performing the repetitive inspections proposed in the AD. The 
commenter indicates that accomplishment of these inspections has proven 
to provide an acceptable level of safety by detecting all cracking 
before a critical cumulative defect size has been exceeded.
    The FAA does not concur with the commenter's request. The FAA finds 
that the requested change is unnecessary because such credit is 
provided by the statement in the AD, ``Required as indicated, unless 
accomplished previously.'' Any operator that has accomplished the 
required inspections may take credit for those inspections provided 
that the repetitive inspections are accomplished in accordance with the 
requirements of this AD.
    The same commenter also requests that paragraphs (a)(1) and (b)(1) 
of the proposed rule be revised to clarify that the modification must 
be accomplished prior to further flight following the third inspection 
accomplished after the effective date of the AD. Since the commenter 
has been conducting the proposed inspections, the FAA infers from this 
commenter's request that it would like credit for those inspections 
without having to modify the wheel subassemblies sooner than the AD 
would require had the operator not conducted any inspections.
    The FAA concurs that clarification is necessary, and has revised 
paragraphs (a)(1) and (b)(1) of the final rule to clarify its intent 
that the modification must be accomplished prior to further flight 
following the third inspection accomplished after the effective date of 
this AD.
    This commenter also requests that paragraph (c) of the proposed 
rule be revised to delete the words ``and modified.'' The commenter 
points out that wheel subassemblies that are inspected in accordance 
with the proposal may remain in service until the third inspection 
after the effective date of the AD, at which time those subassemblies 
must be modified. Therefore, a wheel subassembly that has been 
inspected in accordance with the proposed rule would be considered to 
be safe. The FAA finds that clarification is necessary. Paragraph (c) 
of the final rule has been revised to specify that certain parts may 
not be installed on the airplane unless the part has been inspected and 
subsequently modified in accordance with the requirements of this AD.
    The FAA has revised paragraphs (a)(2) and (b)(2) of the final rule 
to indicate that the replacement procedures required by those 
paragraphs are found in the Airplane Maintenance Manual. This 
information was omitted inadvertently from the proposal.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    The FAA estimates that 87 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 14 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $55 per work hour. Based on these figures, the total cost 
impact of the AD on U.S. operators is estimated to be $66,990, or $770 
per airplane.
    The total cost impact figure discussed above is based on 
assumptions that no operator has yet accomplished any of the 
requirements of this AD action, and that no operator would accomplish 
those actions in the future if this AD were not adopted.
    The regulations adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

94-22-05 Fokker: Amendment 39-9054. 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 accomplished after the effective date of this AD, 
modify the wheel subassembly in accordance with paragraph D. of 
SECTION II--ACCOMPLISHMENT 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 in 
accordance with the Airplane Maintenance Manual. 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 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 (b) of this AD: Prior to further flight following the 
third inspection accomplished after the effective date of this AD, 
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 in 
accordance with the Airplane Maintenance Manual. 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 in accordance with paragraph (a) or (b) of this AD, as 
applicable. Following installation of any such part, the part must 
be repetitively inspected and modified in accordance with paragraphs 
(a) 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 FEB93-0965 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 
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.
    (f) The inspections and modifications shall be done in 
accordance with ABSC Service Bulletin Fo100-32-46, dated December 
24, 1992; or ABSC Service Bulletin Fo100-32-48, dated March 10, 
1993. This incorporation by reference was approved by the Director 
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Fokker Aircraft USA, Inc., 1199 
North Fairfax Street, Alexandria, Virginia 22314. Copies may be 
inspected at the FAA, Transport Airplane Directorate, 1601 Lind 
Avenue, SW., Renton, Washington; or at the Office of the Federal 
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on December 12, 1994.

    Issued in Renton, Washington, on October 24, 1994.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-26719; Filed 11-9-94; 8:45 am]
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