[Federal Register Volume 61, Number 183 (Thursday, September 19, 1996)]
[Rules and Regulations]
[Pages 49248-49250]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-23712]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-59-AD; Amendment 39-9762; AD 96-19-16]
RIN 2120-AA64
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 cracking of the Hi-lok bolt holes in the
main hinge fittings of the horizontal stabilizer, and repair, if
necessary. The amendment also requires modification of the main hinge
fitting, modification or replacement of rib connecting angles, and
modification of ribs. This amendment is prompted by a report indicating
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 this AD are intended to prevent 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: Effective October 24, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of October 24, 1996.
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) 227-1149.
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 13,
1996 (61 FR 5524). That action proposed to 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
certain airplanes, that action also proposed to require modification of
the Hi-lok bolt holes by cold expansion and stiffening of the ribs at
Station 215.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Support for the Proposal
One commenter supports the proposed rule.
Request To Extend the Compliance Time
One commenter requests that the compliance time for the initial
inspection be extended from the proposed 15,000 total flight cycles to
16,000 flight cycles. The commenter considers that extending the
compliance time to 16,000 flight cycles would allow an operator to
accomplish the inspection during regularly scheduled maintenance, and
would prevent any disruption of service. The commenter states that the
adoption of the proposed compliance time would require scheduling of
special times for the accomplishment of this inspection at considerable
expense beyond what was estimated in the cost impact of the proposed
rule.
The FAA does not concur. In developing the compliance time for this
rulemaking action, the FAA took into consideration not only the safety
implications associated with the addressed unsafe condition and the
normal maintenance schedules for the majority of affected operators,
but also the results of fatigue tests and analysis performed by the
manufacturer, the manufacturer's recommended compliance time specified
in the
[[Page 49249]]
applicable service bulletin, and the foreign airworthiness authority's
recommended compliance time of 15,000 total flight cycles. In
consideration of these factors, the FAA finds that a compliance time of
15,000 total flight cycles (or within 1 year after the effective date
of this date) is appropriate and should fall during a time of scheduled
maintenance for the majority of affected operators. However, paragraph
(d) of the final rule does provide affected operators the opportunity
to apply for an adjustment of the compliance time if data are presented
to justify such an adjustment.
Conclusion
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 as proposed.
Cost Impact
The FAA estimates that 90 airplanes of U.S. registry will be
affected by this AD, that it will take approximately 136 work hours per
airplane to accomplish the required actions, and that the average labor
rate is $60 per work hour. Required parts will cost approximately
$1,800 per airplane. Based on these figures, the cost impact of the 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 requirements of this AD
action, and that no operator would accomplish those actions in the
future if this AD were not adopted.
Regulatory Impact
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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
96-19-16 Fokker: Amendment 39-9762. 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.
[[Page 49250]]
(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 actions shall be done in accordance with Fokker Service
Bulletin SBF100-55-021, Revision 2, dated December 27, 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 October 24, 1996.
Issued in Renton, Washington, on September 10, 1996.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-23712 Filed 9-18-96; 8:45 am]
BILLING CODE 4910-13-U
