[Federal Register Volume 63, Number 80 (Monday, April 27, 1998)]
[Proposed Rules]
[Pages 20554-20556]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-11092]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-16-AD]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F.28 Mark 1000, 2000,
3000, and 4000 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the supersedure of an existing
airworthiness directive (AD), applicable to certain Fokker Model F.28
Mark 1000, 2000, 3000, and 4000 series airplanes, that currently
requires an inspection to detect free movement of the actuator servo-
valve sub-assembly of the horizontal stabilizer actuator, and
replacement, if necessary. This action would add a one-time inspection
to determine the residual strength of the servo-valve sub-assembly of
the horizontal stabilizer actuator, and replacement of the actuator
with a new or serviceable actuator, if necessary; and eventual
replacement of the horizontal stabilizer actuator with an improved
actuator. This proposal is prompted by issuance of mandatory continuing
airworthiness information by a foreign civil airworthiness authority.
The actions specified by the proposed AD are intended to prevent
uncommanded trimming or failure of the trim system of the horizontal
stabilizer, and consequent reduced controllability of the airplane.
DATES: Comments must be received by May 27, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-16-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 Services B.V., Technical Support Department, P.O.
Box 75047, 1117 ZN Schiphol Airport, the Netherlands. This information
may be examined at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington.
FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 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.
[[Page 20555]]
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 98-NM-16-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-114, Attention: Rules
Docket No. 98-NM-16-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On August 7, 1992, the FAA issued AD 92-18-04, amendment 39-8348
(57 FR 38432, August 25, 1992), applicable to certain Fokker Model F.28
Mark 1000, 2000, 3000, and 4000 series airplanes, to require an
inspection to detect free movement of the actuator servo-valve sub-
assembly of the horizontal stabilizer actuator, and replacement, if
necessary. That action was prompted by a report of a horizontal
stabilizer malfunction and subsequent uncommanded stabilizer movement
caused by a broken spool in the actuator servo-valve assembly of the
horizontal stabilizer control unit. The requirements of that AD are
intended to prevent uncommanded trimming or failure of the trim system
of the horizontal stabilizer.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the manufacturer and the
Rijksluchtvaartdienst (RLD), which is the airworthiness authority for
the Netherlands, have determined that currently installed servo-valve
sub-assemblies of the horizontal stabilizer may have suffered damage as
a result of excessive control forces experienced during past heavy
operation. This damage could result in a dormant failure of the
actuator servo-valve assembly of the horizontal stabilizer control
unit. This condition, if not corrected, could lead to an uncommanded
nose-up trimming condition in the event of a horizontal stabilizer
servo-valve failure, and consequent reduced controllability of the
airplane.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin F28/27-183, dated November 21,
1994, which describes procedures for a one-time inspection to determine
the residual strength of the servo-valve sub-assembly of the horizontal
stabilizer actuator, and replacement of the actuator with a new or
serviceable actuator, if necessary. The service bulletin also describes
procedures for replacement of the horizontal stabilizer actuator with
an improved actuator that incorporates a revised servo-valve creep
rate. This replacement is intended to ensure that a failure of the
horizontal stabilizer actuator would result in a nose-down trim
position. The RLD classified this service bulletin as mandatory and
issued Dutch airworthiness directive 1992-077/2(A), dated January 31,
1995, in order to assure the continued airworthiness of these airplanes
in the Netherlands.
FAA's Conclusions
These airplane models are manufactured in the Netherlands and are
type certificated for operation in the United States under the
provisions of Sec. 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 supersede AD 92-18-04 to
continue to require an inspection to detect free movement of the
actuator servo-valve sub-assembly of the horizontal stabilizer
actuator, and replacement, if necessary. The proposed AD also would
require a one-time inspection to determine the residual strength of the
servo-valve sub-assembly of the horizontal stabilizer actuator, and
replacement of the actuator with a new or serviceable actuator, if
necessary; and eventual replacement of the horizontal stabilizer
actuator with an improved actuator. The actions would be required to be
accomplished in accordance with the service bulletin described
previously.
Cost Impact
There are approximately 27 airplanes of U.S. registry that would be
affected by this proposed AD.
The inspection that is currently required by AD 92-18-04 would take
approximately 1 work hour per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the currently required actions on U.S. operators is estimated
to be $1,620, or $60 per airplane.
The inspection that is proposed in this new AD action would take
approximately 2 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the proposed inspection of this AD on U.S. operators is
estimated to be $3,240, or $120 per airplane.
The replacement proposed in this new AD action would take
approximately 8 work hours per airplane to accomplish, at an average
labor rate of $60 per work hour. Required parts would be provided by
the manufacturer at no cost to the operator. Based on these figures,
the cost impact of the proposed replacement of this AD on U.S.
operators is estimated to be $12,960, or $480 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the current or 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,
[[Page 20556]]
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 removing amendment 39-8348 (57 FR
38432, August 25, 1992), and by adding a new airworthiness directive
(AD), to read as follows:
Fokker: Docket 98-NM-16-AD. Supersedes AD 92-18-04, Amendment 39-
8348.
Applicability: Model F.28 Mark 1000, 2000, 3000, and 4000 series
airplanes; equipped with Menasco horizontal stabilizer actuators
having part number (P/N)
11100-( ); certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
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 (e) 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 uncommanded trimming or failure of the trim system of
the horizontal stabilizer, and consequent reduced controllability of
the airplane, accomplish the following:
(a) Within 20 days after September 9, 1992 (the effective date
of AD 92-18-04, amendment 39-8348), perform an inspection of the
servo-valve sub-assembly rod-end bearing and servo-valve sub-
assembly for movement, in accordance with Fokker Service Bulletin
F28/27-180, dated July 3, 1992.
(1) If the servo-valve sub-assembly rod-end bearing and servo-
valve sub-assembly move freely within the load limits specified in
the service bulletin, reassemble and conduct a functional test, in
accordance with the service bulletin.
(2) If the servo-valve sub-assembly rod-end bearing or servo-
valve sub-assembly require higher loads for movement than specified
in the service bulletin, prior to further flight, remove and replace
the horizontal stabilizer control unit with a serviceable control
unit that has been inspected and found to be within the load limits
of the service bulletin, or that has been inspected and repaired in
accordance with Chapter 27-42-4 of the Menasco Overhaul Manual
(OHM), as revised by Temporary Revision Number 3, dated July 10,
1992.
(b) Within 6 months after the effective date of this AD, perform
a one-time inspection to determine the residual strength of the
servo-valve sub-assembly of the horizontal stabilizer actuator, in
accordance with Part 1 of the Accomplishment Instructions of Fokker
Service Bulletin F28/27-183, dated November 21, 1994. If any
discrepancy is found, prior to further flight, replace the actuator
with a new or serviceable actuator in accordance with the service
bulletin.
(c) Within 3 years after the effective date of this AD, replace
the horizontal stabilizer actuator with an actuator that has been
modified and re-marked in accordance with Part 2 of the
Accomplishment Instructions of Fokker Service Bulletin F28/27-183,
dated November 21, 1994.
(d) As of the effective date of this AD, no person shall install
a horizontal stabilizer control unit on any airplane, unless the
horizontal stabilizer actuator has been modified and re-marked in
accordance with Part 2 of the Accomplishment Instructions of Fokker
Service Bulletin F28/27-183, dated November 21, 1994.
(e) 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, International Branch, ANM-116, 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, International
Branch, ANM-116.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(f) 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.
Note 3: The subject of this AD is addressed in Dutch
airworthiness directive 1992-007/2(A), dated January 31, 1995.
Issued in Renton, Washington, on April 21, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-11092 Filed 4-24-98; 8:45 am]
BILLING CODE 4910-13-U