[Federal Register Volume 62, Number 33 (Wednesday, February 19, 1997)]
[Rules and Regulations]
[Pages 7340-7343]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3535]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-234-AD; Amendment 39-9929; AD 97-04-05]
RIN 2120-AA64
Airworthiness Directives; Jetstream Model 4101 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
is applicable to certain Jetstream Model 4101 airplanes. This action
requires a one-time inspection of the airplane records to determine the
modification status of the elevator trim servo, and, if necessary,
inspections to determine the serial number of the servo, and repetitive
inspections for looseness or movement of the motor housing of the
servo. This action also requires replacement of certain elevator trim
servos with a serviceable assembly. This
[[Page 7341]]
amendment is prompted by reports of the motor housing separating from
the elevator trim servo and the consequent release of certain component
parts, due to inadequate locking of screws that were installed during
assembly of the servos. The actions specified in this AD are intended
to prevent the motor housing of the elevator trim servo from separating
and releasing component parts that could lodge in and jam the elevator
controls, and result in reduced pitch control of the airplane.
DATES: Effective March 6, 1997.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 6, 1997.
Comments for inclusion in the Rules Docket must be received on or
before April 21, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-234-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from
Jetstream Aircraft, Inc., P.O. Box 16029, Dulles International Airport,
Washington, DC 20041-6029. This information may be examined 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.
FOR FURTHER INFORMATION CONTACT:
William Schroeder, Aerospace Engineer, Standardization Branch, ANM-113,
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2148; fax (206) 227-1149.
SUPPLEMENTARY INFORMATION: The Civil Aviation Authority (CAA), which is
the airworthiness authority for the United Kingdom, recently notified
the FAA that an unsafe condition may exist on certain Jetstream Model
4101 airplanes The CAA advises that it has received reports indicating
that separation of the motor housing from the elevator trim servo and
consequent release of motor gearbox components has occurred on a
Jetstream Model 4101 airplane. Investigation revealed that certain
elevator trim servo units manufactured by Honeywell were assembled
using screws with inadequate locking capability. Certain of these
screws fasten the servo motor inner gear casing to the mounting flange
and some screws fasten the motor cap/sleeve to the inner gear casing.
The inadequate locking of those screws caused the separation of the
motor housing from the servo unit, and resulted in the release of the
motor gearbox components. Those released components could lodge in the
elevator controls and result in an elevator jam. This condition, if not
corrected, could result in reduced control of the primary pitch control
of the airplane.
Explanation of Relevant Service Information
Jetstream has issued Alert Service Bulletin J41-A22-008, Revision
1, dated November 21, 1996, which describes the following procedures:
1. A one-time inspection of the airplane records or a visual
inspection of the servo to determine if the elevator trim servo is at
Modification B standard or greater.
2. For those airplanes on which the elevator trim servo is not at
Modification B or greater, the alert service bulletin describes
procedures for an inspection of the airplane records or a visual
inspection of the elevator trim servo to determine the serial number of
the elevator trim servo, procedures for repetitive visual and tactile
inspections of the motor housing of the elevator trim servo to
determine if the motor housing is loose or moves, and repair of
replacement of the elevator trim servo with a serviceable servo, if
necessary. Replacement of the servo with a serviceable assembly would
eliminate the need for repetitive inspections of the motor housing. The
alert service bulletin also describes procedures for replacement of
certain servos specified in the alert service bulletin with a servo at
Modification B or later standard.
The CAA classified this service bulletin as mandatory in order to
assure the continued airworthiness of these airplanes in the United
Kingdom.
FAA's Conclusions
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, 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 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, this AD is being issued to prevent the motor
housing of the elevator trim servo from separating from the servo
assembly and releasing component parts that could lodge in and jam the
elevator control, and result in reduced pitch control of the airplane.
This AD requires the following:
1. A one-time inspection of the airplane records or a visual
inspection of the servo to determine if the elevator trim servo is at
Modification B standard or greater.
2. For those airplanes on which the elevator trim servo is not at
Modification B standard or greater, an inspection of the airplane
records to determine the serial number of the elevator trim servo,
repetitive visual and tactile inspections of the motor housing of the
elevator trim servo to determine if the motor housing is loose or
moves, and replacement of the elevator trim servo with a serviceable
servo, as necessary.
3. Replacement of certain elevator trim servos with a serviceable
assembly.
The actions are required to be accomplished in accordance with the
alert service bulletin described previously.
Determine of Rule's Effective Date
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for prior
public comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and opportunity for public comment, comments are invited on this
rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD
[[Page 7342]]
action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 96-NM-234-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and that it is not a ``significant regulatory
action'' under Executive Order 12866. It has been determined further
that this action involves an emergency regulation under DOT Regulatory
Policies and Procedures (44 FR 11034, February 26, 1979). If it is
determined that this emergency regulation otherwise would be
significant under DOT Regulatory Policies and Procedures, a final
regulatory evaluation will be prepared and placed in the Rules Docket.
A copy of it, if filed, 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:
97-04-05 Jetstream: Amendment 39-9929. Docket 96-NM-234-AD.
Applicability: Model 4101 airplanes having serial numbers 41004
through 41090 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 (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 separation of the motor housing of the elevator trim
servo from the servo body that would allow detachment of component
parts that could lodge in and jam the elevator control, and result
in reduced control of the primary pitch of the airplane; accomplish
the following:
Note 2: Accomplishment of actions required by this AD in
accordance with Jetstream Alert Service Bulletin J41-A22-008, dated
July 18, 1996, is not considered acceptable for compliance with the
applicable action specified in this AD.
(a) Within 14 days after the effective date of this AD: Perform
either an inspection of the airplane records or a visual inspection
of the elevator trim servo, to determine if the elevator trim servo
is at Modification B standard or greater, in accordance with
Jetstream Alert Service Bulletin J41-A22-008, Revision 1, dated
November 21, 1996.
(b) If the inspection required by paragraph (a) of this AD
reveals that the elevator trim servo is at Modification B standard
or greater: No further action is required by this AD.
(c) If the inspection required by paragraph (a) of this AD
reveals that the elevator trim servo is not at Modification B
standard or greater: Prior to further flight, perform either an
inspection of the airplane records or a visual inspection of the
elevator trim servo, to determine if the serial number of the
elevator trim servo is specified in paragraph 1.M.(4)(b) of
Jetstream Alert Service Bulletin J41-A22-008, Revision 1, dated
November 21, 1996; and, regardless of the serial number, perform
both a visual inspection and a tactile inspection of the motor
housing of the elevator trim servo to determine if the motor housing
is loose or moves, in accordance with the alert service bulletin.
(1) If the motor housing does not move and is not loose, and the
elevator trim servo does not have a serial number that is specified
in paragraph 1.M(4)(b) of the alert service bulletin: No further
action is required by this AD.
(2) If the motor housing does not move and is not loose, but the
elevator trim servo has a serial number that is specified in
paragraph 1.M(4)(b) of the alert service bulletin: Repeat the visual
and tactile inspections of the elevator trim servo thereafter at
intervals not to exceed 50 hours time-in-service, until the
requirements of paragraph (d) of this AD are accomplished.
(3) If the motor housing moves or is loose, regardless of serial
number: Prior to further flight, accomplish the requirements of
either paragraph (c)(3)(i) or (c)(3)(ii) of this AD:
(i) Secure the elevator trim servo and deactivate the autopilot
system, in accordance with Part 3 of the Accomplishment Instructions
of the alert service bulletin. Thereafter, repeat the visual and
tactile inspections at intervals not to exceed 50 hours time-in-
service, until the requirements of paragraph (d) of this AD are
accomplished. Or
(ii) Replace the elevator trim servo with an ``acceptable
replacement'' servo, as defined by the ``Note'' in Paragraph 2.,
Accomplishment Instructions, of Jetstream Alert Service Bulletin
J41-A22-008, Revision 1, dated November 21, 1996. Accomplish the
replacement in accordance with Part 4 of the Accomplishment
Instructions of the alert service bulletin. Accomplishment of this
replacement constitutes terminating action for the repetitive
inspections required by this AD.
(d) For airplanes subject to paragraph (c)(2) or (c)(3)(i) of
this AD: Within 90 days after the effective date of this AD, replace
the elevator trim servo with an ``acceptable replacement'' servo, as
defined by the ``Note'' in Paragraph 2., Accomplishment
Instructions, of Jetstream Alert Service Bulletin J41-A22-008,
Revision 1, dated November 21, 1996. Accomplish the replacement in
accordance with Part 4 of the Accomplishment Instructions of the
alert service bulletin. Accomplishment of this replacement
constitutes terminating action for the repetitive inspections
required by this AD.
(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, 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.
(f) Special flight permits may be issued in accordance with
sections 21.197 and 21.199
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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.
(g) The actions shall be done in accordance with Jetstream Alert
Service Bulletin J41-A22-008, Revision 1, dated November 21, 1996,
which contains the specificed list of effective pages:
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Revision level
Page No. shown on page Date shown on page
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1-10, 15......................... 1 November 21,1996.
11-14, 16, 17.................... (\1\) July 18, 1996.
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\1\ Original.
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 Jetstream Aircraft, Inc., P.O. Box
16029, Dulles International Airport, Washington, DC 20041-6029.
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.
(h) This amendment becomes effective on March 6, 1997.
Issued in Renton, Washington, on February 6, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-3535 Filed 2-18-97; 8:45 am]
BILLING CODE 4910-13-M
