[Federal Register Volume 64, Number 73 (Friday, April 16, 1999)]
[Proposed Rules]
[Pages 18840-18842]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-9512]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-346-AD]
RIN 2120-AA64
Airworthiness Directives; Fokker Model F.28 Mark 0070 and Mark
0100 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 all Fokker Model F.28 Mark
0070 and Mark 0100 series airplanes, that currently requires revising
the Airplane Flight Manual to provide the flightcrew with instructions
not to arm the liftdumper system prior to commanding the landing gear
to extend. This action would require modification of the grounds of the
shielding of the wheelspeed sensor wiring of the main landing gear
(MLG) and installation of new electrical grounds for the wheelspeed
sensor channel of the anti-skid control box of the MLG. 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 electromagnetic
interference generated by electrical wiring that runs parallel to the
wheelspeed sensor wiring, which could result in inadvertent deployment
of the liftdumpers during approach for landing or reduced brake
pressure during low speed taxiing, and consequent reduced
controllability and performance of the airplane.
DATES: Comments must be received by May 17, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-346-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.
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
[[Page 18841]]
Docket Number 98-NM-346-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-346-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
On May 11, 1998, the FAA issued AD 98-11-02, amendment 39-10529 (63
FR 27197, May 18, 1998), applicable to all Fokker Model F.28 Mark 0070
and Mark 0100 series airplanes, to require revising the Airplane Flight
Manual (AFM) to provide the flightcrew with instructions not to arm the
liftdumper system prior to commanding the landing gear to extend. That
action was prompted by issuance of mandatory continuing airworthiness
information by a foreign civil airworthiness authority. The
requirements of that AD are intended to prevent inadvertent deployment
of the liftdumpers during approach for landing, and consequent reduced
controllability and performance of the airplane.
Actions Since Issuance of Previous Rule
Since the issuance of that AD, the Rijksluchtvaartdienst (RLD),
which is the airworthiness authority for the Netherlands, has
determined that the design safety features that provide adequate
electromagnetic interference (EMI) protection of the wheelspeed signal
wiring, and verify erroneous ``high'' wheelspeed signals through the
liftdumper arming test, may not be fully effective. Further analysis
has determined that airplanes on which Fokker Service Bulletins SBF100-
32-067 and SBF100-32-037 have been accomplished are less susceptible to
effects of EMI on the wheelspeed signals. Measurements have indicated
that the EMI is being generated between the electrical wiring supply
for the lights and the electrical wiring for the wheelspeed sensors of
the main landing gear (MLG), which run parallel to each other. If the
EMI reaches a certain level, an erroneous wheelspeed signal may occur,
which could result in inadvertent deployment of the liftdumpers or
reduced brake pressure during low speed taxiing. These conditions, if
not corrected, could result in reduced controllability and performance
of the airplane.
Explanation of Relevant Service Information
Fokker has issued Service Bulletin SBF100-32-067, Revision 1, dated
July 6, 1998, which describes procedures for modification of the ground
wiring to the shielding of the wheelspeed sensor wiring of the MLG. The
modification involves modifying the applicable avionics rack and
installing additional ground wiring to the shielding of the wheelspeed
sensor wiring.
Fokker also has issued Service Bulletin SBF100-32-037, Revision 2,
dated December 4, 1998, which describes procedures for installing new
electrical grounds for the wheelspeed sensor channel of the anti-skid
control box of the MLG. The installation involves re-routing existing
electrical wiring and installing new terminal blocks and electrical
wiring.
These modifications would provide additional grounds to the
shielding of the wheelspeed sensor wiring and to the power supplies of
the anti-skid control box. These additional grounds reduce the effects
of EMI generated by electrical wiring that runs parallel to the
wheelspeed sensor wiring. The RLD classified these service bulletins as
mandatory and issued Dutch airworthiness directives BLA 1998-100, dated
August 31, 1998, and 1998-100/2, dated November 30, 1998, 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 98-11-02 to
continue to require revision of the Limitations and Normal Procedures
sections of the FAA-approved AFM to provide the flightcrew with
instructions not to arm the liftdumper system prior to commanding the
landing gear to extend. In addition, this proposed AD would add
requirements for modification of the grounds of the shielding of the
wheelspeed sensor wiring of the MLG and installation of new electrical
grounds for the wheelspeed sensor channel of the anti-skid control box
of the MLG. The actions would be required to be accomplished in
accordance with the service bulletins described previously.
Interim Action
This is considered to be interim action until final action is
identified, at which time the FAA may consider further rulemaking.
Cost Impact
There are approximately 131 airplanes of U.S. registry that would
be affected by this proposed AD.
For all airplanes, the actions that are currently required by AD
98-11-02 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 $7,860, or $60 per airplane.
There are approximately 127 airplanes of U.S. Registry that would
be required to accomplish the modification and installation. It would
take approximately 33 work hours per airplane to accomplish the
modification and installation, at an average labor rate of $60 per work
hour. Required parts would cost between $755 and $1,236 per airplane.
Based on these figures, the cost impact of the proposed requirements of
this AD on U.S. operators is estimated to be between $347,345 and
$408,432, or between $2,735 and $3,216 per airplane.
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
[[Page 18842]]
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 removing amendment 39-10529 (63 FR
27197, May 18, 1998), and by adding a new airworthiness directive (AD),
to read as follows:
Fokker Services B.V.: Docket 98-NM-346-AD. Supersedes AD 98-11-02,
Amendment 39-10529.
Applicability: All Model F.28 Mark 0070 and Mark 0100 series
airplanes, 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 (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 electromagnetic interference generated by electrical
wiring that runs parallel to the wheelspeed sensor wiring, which
could result in inadvertent deployment of the liftdumpers during
approach for landing or reduced brake pressure during low speed
taxiing, and consequent reduced controllability and performance of
the airplane, accomplish the following:
Restatement of Requirements of AD 98-11-02, Amendment 39-10529
(a) Within 5 days after June 2, 1998 (the effective date of AD
98-11-02), revise the Limitations and Normal Procedures sections of
the FAA-approved Airplane Flight Manual (AFM) in accordance with
paragraphs (a)(1) and (a)(2) of this AD. This may be accomplished by
inserting a copy of this AD in the AFM.
(1) Add the following information to section 5--NORMAL
PROCEDURES, sub-Section APPROACH AND LANDING, after the subject
APPROACH:
``Before Landing
WARNING: DO NOT ARM THE LIFTDUMPER SYSTEM BEFORE LANDING GEAR
DOWN SELECTION.
Selecting Landing Gear DOWN after arming the liftdumper system
may result in inadvertent deployment of the liftdumpers, because the
liftdumper arming test may be partially ineffective.''
(2) Add the following information to the LIMITATIONS section:
``Liftdumper System
DO NOT ARM THE LIFTDUMPER SYSTEM BEFORE LANDING GEAR DOWN
SELECTION.''
New Requirements of This AD
Corrective Actions
(b) For Model F.28 Mark 0100 series airplanes having serial
numbers as listed in Fokker Service Bulletin SBF100-32-067, Revision
1, dated July 6, 1998: Within 6 months after the effective date of
this AD, modify the grounds of the shielding of the wheelspeed
sensor wiring of the main landing gear (MLG) in accordance with Part
1, 2, 3, or 4 of the Accomplishment Instructions of the service
bulletin, as applicable.
Note 2: Modifications accomplished prior to the effective date
of this AD in accordance with Fokker Service Bulletin SBF100-32-067,
dated March 12, 1993, are considered acceptable for compliance with
the requirements of paragraph (b) of this AD.
(c) For Model F.28 Mark 0100 series airplanes having serial
numbers listed in Fokker Service Bulletin SBF100-32-037, Revision 2,
dated December 4, 1998: Within 12 months after the effective date of
this AD, install new electrical grounds for the wheelspeed sensor
channel of the anti-skid control box of the MLG in accordance with
Part 1, 2, or 3 of the Accomplishment Instructions of the service
bulletin, as applicable.
Note 3: Installations accomplished prior to the effective date
of this AD in accordance with Fokker Service Bulletin SBF100-32-037,
dated November 12, 1990, or Revision 1, dated November 16, 1998, are
considered acceptable for compliance with the requirements of
paragraph (c) of this AD.
Alternative Methods of Compliance
(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, 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 4: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
Special Flight Permits
(e) Special flight permits may be issued in accordance with
Secs. 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 5: The subject of this AD is addressed in Dutch
airworthiness directives BLA 1998-100, dated August 31, 1998 and
1998 100/2, dated November 30, 1998.
Issued in Renton, Washington, on April 9, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-9512 Filed 4-15-99; 8:45 am]
BILLING CODE 4910-13-U
