[Federal Register Volume 61, Number 191 (Tuesday, October 1, 1996)]
[Rules and Regulations]
[Pages 51212-51213]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-25039]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-129-AD; Amendment 39-9677; AD 96-13-09]
RIN 2120-AA64
Airworthiness Directives; Jetstream Model 4101 Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; correction.
-----------------------------------------------------------------------
SUMMARY: This amendment clarifies information in an existing
airworthiness directive (AD), applicable to all Jetstream 4101
airplanes, that currently requires a review of maintenance records to
determine the time-in-service of the bearings in the starter/generators
of both engines. It also establishes a new time-in-service limit for
the bearings, and requires replacement of the starter/generator unit
with a serviceable unit, if necessary. The actions specified in that AD
are intended to prevent failure of the bearings of the starter/
generator, which could cause severe vibrations and resultant in-flight
shutdown of one or both engines. This amendment clarifies the
requirements of the current AD by specifying the name of the
manufacturer of the starter/generator units that are affected by the
requirements of this AD.
DATES: Effective July 15, 1996.
The incorporation by reference of certain publications listed in
the regulations was approved previously by the Director of the Federal
Register as of July 15, 1996 (61 FR 33647, June 28, 1996).
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: On June 17, 1996, the FAA issued AD 96-13-
09, amendment 39-9677 (61 FR 33647, June 28, 1996), which is applicable
to all Jetstream Model 4101 airplanes. That AD requires a review of
maintenance records to determine the time-in-service of the bearings in
the starter/generators of both engines. It also establishes a new time-
in-service limit for the bearings, and requires replacement of the
starter/generator unit with a serviceable unit, if necessary. That AD
was prompted by reports of controlled in-flight engine shutdowns
resulting from severe vibration caused by the failure of the bearings
in the direct current (DC) starter/generator unit. The actions
specified in that AD are intended to prevent such failure of the
bearings of the starter/generator, which could cause severe vibrations
and resultant in-flight shutdown of one or both engines.
Actions Since Issuance of AD 96-13-09
Since the issuance of that AD, the FAA has been advised that there
may be confusion on the part of operators as to which specific make and
model of starter/generator units are susceptible to the bearing problem
and should be subject to the requirements of the AD. Additionally,
operators of airplanes other than Jetstream Model 4101 airplanes may be
confused as to whether starter/generator units installed on those
airplanes are also susceptible to the bearing problem. Such confusion
arises because the name of the manufacturer of the affected units was
not specified in AD 96-13-09.
The FAA notes that there are several manufacturers of starter/
generator units, but only those manufactured by Lucas Aerospace Power
Systems for Jetstream Model 4101 airplanes are installed on the
affected airplanes and are subject to
[[Page 51213]]
the AD. Lucas Aerospace Power Systems starter/generator units installed
on other makes and models of airplanes are not affected by this AD.
Likewise, other makes and models of starter/generator units installed
on airplanes other than the Model 4101 are not affected by this AD.
In light of the possible confusion that may have been created
relative to this point, the FAA finds that AD 96-13-09 should be
clarified to specify the name of the manufacturer of the affected
starter/generator units.
In all other respects, however, the AD is correct and adequate as
issued.
Action Taken by FAA
Action is taken herein to clarify AD 96-13-09 by identifying the
name of the manufacturer of the subject starter/generators, and to
correctly add the AD as an amendment to section 39.13 of the Federal
Aviation Regulations (14 CFR 39.13).
The final rule is being reprinted in its entirety for the
convenience of affected operators. The effective date remains July 15,
1996.
Since this action only clarifies a current requirement, it has no
adverse economic impact and imposes no additional burden on any person.
Therefore, notice and public procedures hereon are unnecessary.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Correction
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 correctly adding the following new
airworthiness directive:
96-13-09 Jetstream Aircraft Limited: Amendment 39-9677. Docket 96-
NM-129-AD.
Applicability: All Model 4101 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 (c) 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 severe vibration of one or both engines, which could
cause in-flight engine shutdown, accomplish the following:
(a) Within 7 days after the effective date of this AD, review
the airplane maintenance records to determine the hours time-in-
service (TIS) accumulated on the bearings in the Lucas Aerospace
Power Systems starter/generator units of both engines, in accordance
with Jetstream Alert Service Bulletin J41-A24-036, dated February
26, 1996.
(1) If the bearings on both of the starter/generator units have
accumulated 300 or more hours TIS: Prior to further flight, replace
at least one of the starter/generator units with a unit having
bearings with less than 300 hours TIS, in accordance with the alert
service bulletin.
(2) If the bearings on one or both starter/generator units have
bearings with less than 300 hours TIS: Prior to the accumulation of
300 hours TIS on the bearings on both starter/generator units,
remove at least one of the units and replace it with a unit having
bearings with less than 300 hours TIS, in accordance with the alert
service bulletin.
(b) As a continuing requirement thereafter: Prior to the
accumulation of 300 hours TIS on the bearings on both of the Lucas
Aerospace Power Systems starter/generator units on the airplane,
remove at least one of those units and replace it with a unit having
bearings with less than 300 hours TIS, in accordance with Jetstream
Alert Service Bulletin J41-A24-036, dated February 26, 1996.
(c) 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 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.
(d) 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.
(e) The actions shall be done in accordance Jetstream Alert
Service Bulletin J41-A24-036, dated February 26, 1996. This
incorporation by reference was approved previously by the Director
of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1
CFR part 51, as of July 15, 1996 (61 FR 33647, June 28, 1996).
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.
(f) This amendment becomes effective on July 15, 1996.
Issued in Renton, Washington, on September 24, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-25039 Filed 9-30-96; 8:45 am]
BILLING CODE 4910-13-U
