[Federal Register Volume 63, Number 116 (Wednesday, June 17, 1998)]
[Proposed Rules]
[Pages 33018-33019]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-16024]
[[Page 33018]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-CE-32-AD]
RIN 2120-AA64
Airworthiness Directives; British Aerospace Jetstream Model 3101
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to adopt a new airworthiness directive
(AD) that would apply to certain British Aerospace Jetstream Model 3101
airplanes. The proposed AD would require replacing the elevator trim
servo motor with a new motor of improved design and inspecting the
cable tension and electrical operation of the elevator and trim tab for
proper operation and making any necessary adjustments. The proposed AD
is the result of mandatory continuing airworthiness information (MCAI)
issued by the airworthiness authority for the United Kingdom. The
actions specified by the proposed AD are intended to prevent the
elevator trim servo motor drive gear assembly from remaining engaged
when the autopilot is disengaged, which could result in the pilot
having to manually overpower the elevator trim control and possibly
lose directional control of the airplane during critical phases of
flight.
DATES: Comments must be received on or before July 24, 1998.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Regional Counsel,
Attention: Rules Docket No. 98-CE-32-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106. Comments may be inspected at this location
between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.
Service information that applies to the proposed AD may be obtained
from British Aerospace Regional Aircraft, Prestwick International
Airport, Ayrshire, KA9 2RW, Scotland; telephone: (01292) 479888;
facsimile: (01292) 479703. This information also may be examined at the
Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Mr. S.M. Nagarajan, Aerospace
Engineer, FAA, Small Airplane Directorate, Aircraft Certification
Service, 1201 Walnut, suite 900, Kansas City, Missouri 64106;
telephone: (816) 426-6932; facsimile: (816) 426-2169.
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 should 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 that summarizes 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 No. 98-CE-32-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, Central Region, Office of the Regional Counsel, Attention:
Rules Docket No. 98-CE-32-AD, Room 1558, 601 E. 12th Street, Kansas
City, Missouri 64106.
Discussion
The Civil Airworthiness Authority (CAA), which is the airworthiness
authority for the United Kingdom, notified the FAA that an unsafe
condition may exist on certain British Aerospace Jetstream Model 3101
airplanes that are equipped with an autopilot. The CAA reports that an
elevator trim servo motor in the autopilot failed on a Jetstream Model
3101 airplane, causing the pilot to use extreme force to manually
rotate the elevator trim control handwheel. The investigation showed
that the leaf spring in the solenoid assembly of the elevator trim
servo motor fractured. This fracture caused the servo motor drive gear
assembly to remain engaged, even with the solenoid de-energized and the
autopilot disengaged. This condition occurs from residual magnetism in
the solenoid core, which keeps the armature depressed.
These conditions, if not corrected, could result in loss of
directional control of the airplane during critical phases of flight.
Relevant Service Information
British Aerospace has issued Jetstream Service Bulletin 22-A-JA
860413, dated April 16, 1986, which specifies procedures for replacing
the elevator trim servo motor; and Jetstream Alert Service Bulletin 22-
A-JA 851231, dated April 9, 1986, which specifies procedures for
inspecting the cable tension and electrical operation of the elevator
trim, along with testing and adjusting, if necessary, the friction and
the electric trim manual override loads after the installation of the
new elevator trim servo motor.
The CAA classified these service bulletins as mandatory in order to
assure the continued airworthiness of these airplanes in the United
Kingdom. The CAA classifying a service bulletin as mandatory is the
same in the United Kingdom as the FAA issuing an AD in the United
States.
The FAA's Determination
This airplane model is manufactured in the United Kingdom 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 CAA has kept the FAA
informed of the situation described above.
The FAA has examined the findings of the CAA; reviewed all
available information, including the service information referenced
above; and determined that AD action is necessary for products of this
type design that are certificated for operation in the United States.
Explanation of the Provisions of the Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop in other British Aerospace Jetstream Model 3101
airplanes of the same type design registered in the United States, the
FAA is proposing AD action. The proposed AD would require replacing the
elevator trim servo motor with one of improved design, inspecting the
cable tension and electrical operation, testing the friction and the
[[Page 33019]]
electric trim manual override loads after the new motor is installed,
and making any necessary adjustments. Accomplishment of the proposed
modification would be in accordance with the service bulletins
previously referenced.
Cost Impact
The FAA estimates that 25 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 6
workhours per airplane to accomplish the proposed action, and that the
average labor rate is approximately $60 an hour. The manufacturer will
provide parts at no cost to the owner/operator. Based on these figures,
the total cost impact of the proposed AD on U.S. operators is estimated
to be $9,000, or $360 per airplane.
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 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) 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 has been placed 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 a new airworthiness directive
(AD) to read as follows:
British Aerospace: Docket No. 98-CE-32-AD.
Applicability: Jetstream Model 3101 airplanes, certificated in
any category, with the following serial numbers, that are equipped
with an autopilot:
Serial Numbers
601 603 604 606 607 609
610 612 614 616 620 621
622 626 629 634 637 641
645 648 649 655 665 686
690
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 within the next 100 hours time-in-service
(TIS) after the effective date of this AD, unless already
accomplished.
To prevent the elevator trim servo motor drive gear assembly
from remaining engaged when the autopilot is disengaged, which could
result in the pilot having to manually overpower the elevator trim
control, and possibly lose directional control of the airplane
during critical phases of flight, accomplish the following:
(a) Replace the elevator trim servo motor with a new elevator
trim servo motor of improved design at fuselage station (F.S.) 421,
aft of the rear bulkhead, in accordance with the ACCOMPLISHMENT
INSTRUCTIONS section in JETSTREAM Alert Service Bulletin (SB) 22-A-
JA 860413, ORIGINAL ISSUE: April 16, 1986.
(b) Inspect the cable tension, system friction, and electric
trim manual override and make any necessary adjustments in
accordance with the ACCOMPLISHMENT INSTRUCTIONS section in JETSTREAM
SB No. 22-A-JA 851231, ORIGINAL ISSUE: April 9, 1986.
(c) 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.
(d) An alternative method of compliance or adjustment of the
compliance time that provides an equivalent level of safety may be
approved by the Manager, Small Airplane Directorate, Aircraft
Certification Service, 1201 Walnut, suite 900, Kansas City, Missouri
64106. The request shall be forwarded through an appropriate FAA
Maintenance Inspector, who may add comments and then send it to the
Manager, Small Airplane Directorate.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Small Airplane Directorate.
(e) Questions or technical information related to British
Aerospace Jetstream Service Bulletin 22-A-JA 851231, dated April 9,
1986, and Jetstream Alert Service Bulletin 22-A-JA 860413, dated
April 16, 1986, should be directed to British Aerospace Regional
Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW,
Scotland; telephone: (01292) 479888; facsimile: (01292) 479703. This
service information may be examined at the FAA, Central Region,
Office of the Regional Counsel, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Note 3: The subject of this AD is addressed in British Aerospace
Jetstream Service Bulletin 22-A-JA 851231, dated April 9, 1986, and
British Aerospace Jetstream Service Bulletin 22-A-JA 860413, dated
April 16, 1998. These service bulletins are classified as mandatory
by the United Kingdom Civil Aviation Authority (CAA).
Issued in Kansas City, Missouri, on June 9, 1998.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 98-16024 Filed 6-16-98; 8:45 am]
BILLING CODE 4910-13-U
