[Federal Register Volume 61, Number 218 (Friday, November 8, 1996)]
[Proposed Rules]
[Pages 57832-57834]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-28690]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-154-AD]
RIN 2120-AA64
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 loosening certain nuts on
the horizontal stabilizer control unit (HSCU) to reduce stress on
bolts; a one-time inspection of certain bolts on the HSCU to detect
cracking, and replacement, if necessary; application of corrosion
protection to these bolts; and reassembly and reidentification of the
modified HSCU. This proposal is prompted by reports indicating that
stress corrosion, resulting from overtightening of nuts on these bolts,
has caused some of these bolts to crack and fail. The actions specified
by the proposed AD are intended to prevent failure of these bolts
because of stress corrosion cracking which, if not corrected, could
lead to loss of control of the horizontal stabilizer and reduced
controllability of the airplane.
DATES: Comments must be received by December 20, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-154-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 96-NM-154-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. 96-NM-154-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 has received reports indicating that
lower bolts joining the dog-links to the pistons of the horizontal
stabilizer control unit (HSCU) have cracked and failed on some
airplanes. For the dog-links to disconnect from the pistons, both lower
bolts would have to fail; no disconnections, however, have been
reported.
Investigation revealed that overtightening of the nuts on these
bolts resulted in stress corrosion, which caused bolts to crack and
fail. This condition, if not corrected, could lead to loss of control
of the horizontal stabilizer and reduced controllability of the
airplane.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF100-27-069, dated January 1,
1996, as revised by Service Bulletin Change Notification SBF100-27-069/
01, dated January 8, 1996, which describes procedures for loosening
(reducing the torque value) the nuts on the lower bolts that join the
dog-links to the pistons of the horizontal stabilizer control unit
(HSCU); a one-time inspection of these bolts to detect cracking, and
replacement of discrepant bolts with serviceable bolts; application of
corrosion protection to these bolts; and reassembly and
reidentification of the HSCU that has been modified. The service
bulletin references Menasco Aerospace Ltd. Service Bulletin 23100-27-
19, dated November 10, 1995, as an additional source of service
information for these procedures. The RLD classified the Fokker service
bulletin, Fokker service bulletin change notification, and Menasco
Aerospace Ltd. service bulletin as mandatory, and issued Netherlands
airworthiness directive BLA 1996-006 (A), dated January 31, 1996, in
order to assure the continued airworthiness of these airplanes in the
Netherlands.
FAA's Conclusions
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.
Explanation of Requirements of Proposed Rule
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
[[Page 57833]]
loosening of nuts on lower bolts that join the dog-links to the pistons
of the HSCU; a one-time inspection of these bolts to detect cracking,
and replacement of discrepant bolts with serviceable bolts; application
of corrosion protection to these bolts; and reassembly and
reidentification of the HSCU that has been modified. (Some airplanes
were modified on the production line, but the HSCU was not
reidentified. This proposal would require that the HSCU on those
airplanes also be reidentified.).
The proposed actions would be required to be accomplished in
accordance with the service bulletins and service bulletin change
notification described previously.
Cost Impact
The FAA estimates that 125 Fokker Model F28 Mark 0100 series
airplanes of U.S. registry would be affected by this proposed AD, that
it would take approximately 5 work hours per airplane to accomplish the
proposed loosening of nuts, and that the average labor rate is $60 per
work hour. Based on these figures, the cost impact of the proposed AD
on U.S. operators is estimated to be $37,500, or $300 per airplane.
The FAA also estimates that it would take approximately 6 work
hours per airplane to accomplish the proposed inspection, apply
corrosion protection to the bolts, and reassemble and reidentify the
HSCU. The average labor rate is $60 per work hour. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $45,000, or $360 per airplane.
There currently are no known airplanes of U.S. registry that would
be required to accomplish the proposed reidentification of the HSCU
because the HSCU was modified on the production line and not
reidentified.
The cost impact figures discussed above are 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.
Regulatory Impact
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
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 96-NM-154-AD.
Applicability: Model F28 Mark 100 series airplanes, as listed in
Fokker Service Bulletin SBF100-27-069, dated January 1, 1996;
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 failure of the lower bolts that join the dog-links to
the piston of the horizontal stabilizer control unit (HSCU) because
of stress corrosion cracking, which could result in loss of control
of the horizontal stabilizer and reduced controllability of the
airplane, accomplish the following:
(a) Within 3 months after the effective date of this AD, loosen
the nut [part number (P/N) MS17825-10] on each lower bolt (P/N
23233-1) that joins the dog-links to the piston of the HSCU, in
accordance with Part 1 of the Accomplishment Instructions of Fokker
Service Bulletin SBF100-27-069, dated January 1, 1996, as revised by
Part 1 of Fokker Service Bulletin Change Notification SBF100-27-069/
01, dated January 8, 1996; and Part A of the Accomplishment
Instructions of Menasco Aerospace Ltd. Service Bulletin 23100-27-19,
dated November 10, 1995.
(b) Within 6 months after the effective date of this AD, inspect
each lower bolt (P/N 23233-1) that joins the dog-links to the
pistons of the HSCU to detect cracking and failure, in accordance
with the Part 2 of the Accomplishment Instructions of Fokker Service
Bulletin SBF100-27-069, dated January 1, 1996, as revised by Part 2
of Fokker Service Bulletin Change Notification SBF100-27-069/01,
dated January 8, 1996; and Part B of the Accomplishment Instructions
of Menasco Aerospace Ltd. Service Bulletin 23100-27-19, dated
November 10, 1995.
(1) If no cracking or failure is detected, prior to further
flight, apply corrosion protection to each bolt, and reassemble and
reidentify the HSCU, in accordance with Part 2 of the Accomplishment
Instructions of Fokker Service Bulletin SBF100-27-069, dated January
1, 1996, as revised by Part 2 of Fokker Service Bulletin Change
Notification SBF100-27-069/01, dated January 8, 1996; and Part B of
the Accomplishment Instructions of Menasco Aerospace Ltd. Service
Bulletin 23100-27-19, dated November 10, 1995.
(2) If any cracking or failure is detected, prior to further
flight, replace the discrepant bolt with a serviceable bolt, apply
corrosion protection to each serviceable bolt, and reassemble and
identify the HSCU, in accordance with Part 2 of the Accomplishment
Instructions of Fokker Service Bulletin SBF100-27-069, dated January
1, 1996, as revised by Part 2 of Fokker Service Bulletin Change
Notification SBF100-27-069/01, dated January 8, 1996; and Part B of
the Accomplishment Instructions of Menasco Aerospace Ltd. Service
Bulletin 23100-27-19, dated November 10, 1995.
(c) For airplanes having serial numbers 11500, 11505, and 11511:
Within 6 months after the effective date of this AD, reidentify the
HSCU in accordance with Part 3 of the Accomplishment Instructions of
Fokker Service Bulletin SBF100-27-069, dated January 1, 1996.
(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
[[Page 57834]]
Inspector, who may add comments and then send it to the Manager,
Standardization Branch, ANM-113.
Note 2: 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 November 1, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-28690 Filed 11-7-96; 8:45 am]
BILLING CODE 4910-13-U
