[Federal Register: May 16, 2003 (Volume 68, Number 95)]
[Rules and Regulations]
[Page 26478-26481]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr16my03-2]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2003-NE-16-AD; Amendment 39-13145; AD 2003-08-52]
RIN 2120-AA64
Airworthiness Directives; GE Aircraft Engines CT7-9B Turboprop
Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final rule; request for comments.
-----------------------------------------------------------------------
SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) 2003-08-52 that was sent
previously to all known U.S. owners and operators of GE Aircraft
Engines (GEAE) CT7-9B turboprop engines. This AD requires rigging the
compressor variable geometry (VG) to VG schedule N. This AD is prompted
by reports of 12 compressor stall events that occurred over a six-month
period. The actions specified in this AD are intended to prevent a
dual-engine in-flight shutdown or power loss due to a compressor stall
during deceleration from takeoff power to climb power.
DATES: Effective June 2, 2003, to all persons except those persons to
whom it was made immediately effective by emergency AD 2003-08-52,
issued on April 15, 2003, which contained the requirements of this
amendment. The Director of the Federal Register approved the
incorporation by reference of certain publications listed in the
regulations as of June 2, 2003.
We must receive any comments on this AD by July 15, 2003.
[[Page 26479]]
ADDRESSES: Use one of the following addresses to submit comments on
this AD:
[sbull] By mail: The Federal Aviation Administration (FAA), New
England Region, Office of the Regional Counsel, Attention: Rules Docket
No. 2003-NE-16-AD, 12 New England Executive Park, Burlington, MA 01803-
5299.
[sbull] By fax: (781) 238-7055.
[sbull] By e-mail: 9-ane-adcomment@faa.gov. You may get the service information referenced in this AD from GE
Aircraft Engines Customer Support Center, M/D 285, 1 Neumann Way,
Evendale, OH 45215, telephone (513) 552-3272, fax (513) 552-3329, e-
mail GEAE.csc@ae.ge.com. You may examine the AD docket, by appointment, at the FAA, New
England Region, Office of the Regional Counsel, 12 New England
Executive Park, Burlington, MA. You may examine the service
information, by appointment, at the FAA, New England Region, Office of
the Regional Counsel, 12 New England Executive Park, Burlington, MA; or
at the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Anthony W. Cerra Jr., Aerospace
Engineer, Engine Certification Office, FAA, Engine and Propeller
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299,
telephone (781) 238-7128; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: On April 15, 2003, we issued emergency AD
2003-08-52, that is applicable to GEAE CT7-9B turbofan engines. That
emergency AD requires rigging the compressor VG to VG schedule N. That
action was prompted by reports of 12 compressor stall events that
occurred over a six-month period. This is in contrast to recent
historical experience of four to six stall events per year. The stall
events have occurred on deceleration when transitioning from takeoff
power to climb power. Of the 10 events under investigation, nine had
the compressor VG rigged to the VG schedule N1. The manufacturer's
maintenance manuals and related service bulletins permit the compressor
VG to be rigged to either the VG schedule N or the VG schedule N1. The
VG schedule N provides a higher stall margin at the expense of a small
reduction of engine performance margin as compared to the VG schedule
N1. Since 1992, the manufacturer has recommended that overhaul shops
use the VG schedule N only. VG schedule N provides more stall margin on
used engines, which inherently have a lower stall margin due to wear or
deterioration. Other factors that contribute to lower stall margins
include dirty compressors and the increased compressor clearances that
occur during the first takeoff of the day. This condition, if not
corrected, could result in a dual-engine in-flight shutdown or power
loss due to a compressor stall during deceleration from takeoff power
to climb power.
Relevant Service Information
We have reviewed and approved the technical contents of GEAE Alert
Service Bulletin (ASB) No. CT7-TP S/B 72-A0328, Revision 1, dated April
8, 2003. That ASB describes procedures for rigging the compressor VG to
the VG schedule N.
FAA's Determination and Requirements of This AD
The unsafe condition described previously is likely to exist or
develop on other GEAE CT7-9B turboprop engines of the same type design.
Therefore, we are issuing this AD to prevent a dual-engine in-flight
shutdown or power loss due to a compressor stall during deceleration
from takeoff power to climb power. This AD requires:
[sbull] If both engines on the airplane are rigged to VG schedule
N1, rigging the compressor VG on one engine to VG schedule N within 30
flight hours (FH) or 3 days after the effective date of this AD,
whichever occurs later and,
[sbull] Rigging the remaining engine compressor VG to VG schedule N
within 100 FH or 10 days after the effective date of this AD, whichever
occurs earlier.
[sbull] If only one engine is rigged to VG schedule N1, rigging the
compressor VG to VG schedule N within 100 FH or 10 days after the
effective date of this AD, whichever occurs earlier.
You must do the actions per GEAE ASB No. CT7-TP S/B 72-A0328, Revision
1, dated April 8, 2003, described previously.
FAA's Determination of the Effective Date
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment were impracticable and
contrary to the public interest and that good cause existed to make the
AD effective immediately on April 15, 2003, to all known U.S. owners
and operators of GEAE CT7-9B turboprop engines. These conditions still
exist, and we are publishing the AD in the Federal Register as an
amendment to section 39.13 of part 39 of the Federal Aviation
Regulations (14 CFR part 39) to make it effective to all persons.
Changes to 14 CFR Part 39--Effect on the AD
On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR
47997, July 22, 2002), which governs our AD system. This regulation now
includes material that relates to special flight permits, alternative
methods of compliance, and altered products. This material previously
was included in each individual AD. Since this material is included in
14 CFR part 39, we will not include it in future AD actions.
Interim Action
The investigation to determine the root causes of the decel stall
events is ongoing. We may take further rulemaking action when we have
identified the root causes.
Comments Invited
This AD is a final rule that involves requirements affecting flight
safety and was not preceded by notice and an opportunity for public
comment; however, we invite you to submit any written relevant data,
views, or arguments regarding this AD. Send your comments to an address
listed under ADDRESSES. Include ``AD Docket No. 2003-NE-16-AD'' in the
subject line of your comments. If you want us to acknowledge receipt of
your mailed comments, send us a self-addressed, stamped postcard with
the docket number written on it; we will date-stamp your postcard and
mail it back to you. We specifically invite comments on the overall
regulatory, economic, environmental, and energy aspects of the rule
that might suggest a need to modify it. If a person contacts us through
a nonwritten communication, and that contact relates to a substantive
part of this AD, we will summarize the contact and place the summary in
the docket. We will consider all comments received by the closing date
and may amend the AD in light of those comments.
We are reviewing the writing style we currently use in regulatory
documents. We are interested in your comments on whether the style of
this document is clear, and your suggestions to improve the clarity of
our communications with you. You may get more information about plain
language at http://www.plainlanguage.gov.
Regulatory Findings
We have determined that this AD will not have federalism
implications under Executive Order 13132. This AD will not have a
substantial direct effect on
[[Page 26480]]
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.
For the reasons discussed above, I certify that the 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. 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.
We prepared a summary of the costs to comply with this AD and
placed it in the AD Docket. You may get a copy of this summary by
sending a request to us at the address listed under ADDRESSES. Include
``AD Docket No. 2003-NE-16-AD'' in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by
reference, Safety.
Adoption of the Amendment
0
Accordingly, under 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
0
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]
0
2. The FAA amends Sec. 39.13 by adding the following new airworthiness
directive:
2003-08-52 GE Aircraft Engines: Amendment 39-13145. Docket No. 2003-
NE-16-AD.
Effective Date
(a) This amendment becomes effective June 2, 2003, to all
persons except those persons to whom it was made immediately
effective by emergency AD 2003-08-52, issued April 15, 2003.
Affected ADs
(b) None.
Applicability
(c) This AD applies to GEAE CT7-9B turboprop engines. These
engines are installed on, but not limited to Saab Aircraft AB 340B
airplanes.
Unsafe Condition
(d) This AD was prompted by reports of 12 compressor stall
events that occurred over a six month period. The actions specified
in this AD are intended to prevent a dual-engine in-flight shutdown
or power loss due to a compressor stall during deceleration from
takeoff power to climb power.
Compliance
(e) Compliance with the requirements of this AD is required as
indicated unless already done.
Determining Compressor VG Rigging Schedule
(f) Determine which schedule was used to rig the compressor VG.
The serial numbers (SNs) contained in Table 1 of this AD are known
to have been rigged to VG schedule N1. Engines with SNs that are not
listed in Table 1 might be rigged to VG schedule N1. You must review
the engine records to determine if the engines are rigged to VG
schedule N1 using GEAE Service Bulletin (SB) No. CT7-TP S/B 72-0241,
dated April 6, 1990. Table 1 follows:
Table 1.--SNs of Engines Known to Have Been Rigged to VG Schedule N1
----------------------------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------------------------
785102 785104 785106 785107 785109 785111
785112 785113 785117 785118 785125 785128
785129 785131 785133 785136 785138 785148
785150 785151 785152 785154 785160 785185
785188 785211 785231 785232 785234 785235
785237 785239 785241 785257 785259 785265
785266 785275 785322 785325 785326 785334
785375 785391 785400 785459 785460 785462
785465 785474 785476 785477 785480 785481
785487 785499 785506 785534 785538 785554
785569 785591 785592 785598 785603 785700
785759
----------------------------------------------------------------------------------------------------------------
Rigging the Compressor VG to Schedule N
(g) If the compressor VGs of both engines on the airplane are
rigged to VG schedule N using GEAE SB CT7-TP S/B 72-0328 dated June
9, 1992 or GEAE Alert Service Bulletin (ASB) CT7-TP S/B 72-A0328,
Revision 1, dated April 8, 2003 no further action is required.
(h) If the compressor VGs on both engines on the airplane are
rigged to VG schedule N1, do the following:
(1) Within 30 flight hours (FH) or 3 days after the effective
date of this AD, whichever occurs later, rig the compressor VG on
one engine to VG schedule N in accordance with 3.A.(1) through
3.A.(12) of the Accomplishment Instructions of GEAE ASB No. CT7-TP
S/B 72-A0328, Revision 1, dated April 8, 2003.
(2) Within 100 FH or 10 days after the effective date of this
AD, whichever occurs earlier, rig the compressor VG on the remaining
engine to VG schedule N in accordance with 3.A.(1) through 3.A.(12)
of the Accomplishment Instructions of GEAE ASB No. CT7-TP S/B 72-
A0328, Revision 1, dated April 8, 2003.
(i) If the compressor VG on one engine on the airplane is rigged
to VG schedule N1, within 100 FH or 10 days after the effective date
of this AD, whichever occurs earlier, rig the compressor VG to VG
schedule N in accordance with 3.A.(1) through 3.A.(12) of the
Accomplishment Instructions of GEAE ASB No. CT7-TP S/B 72-A0328,
Revision 1, dated April 8, 2003.
Installation of Engines With VG Schedule N1
(j) After the effective date of this AD, do not install any CT7-
9B turboprop engine that is rigged to VG schedule N1 on to any Saab
Aircraft AB 340B airplane.
Alternative Methods of Compliance
(k) Alternative methods of compliance must be requested in
accordance with 14 CFR part 39.19, and must be approved by the
Manager, Engine Certification Office, Federal Aviation
Administration (FAA).
Material Incorporated by Reference
(l) The rigging of the compressor VG must be done in accordance
with GE Aircraft Engines Alert Service Bulletin (ASB) No. CT7-TP S/B
72-A0328, Revision 1, dated April 8, 2003. The Director of the
Federal Register approved the incorporation by reference of this
service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. You may get a copy from GE Aircraft Engines Customer Support
Center, M/D 285, 1 Neumann Way, Evendale, OH 45215, telephone (513)
552-3272, fax (513) 552-3329, email GEAE.csc@ae.ge.com. You may
review copies at the FAA, New England Region, Office of the Regional
Counsel, 12 New England Executive Park, Burlington, MA; or at the
Office of the Federal Register, 800 North Capitol Street, NW, suite
700, Washington, DC.
Related Information
(m) Additional information to help minimize the occurrence of
multiple-engine in-flight shutdowns or power loss may be
[[Page 26481]]
found in GEAE All Operator's Wire CT7-03-02, dated April 3, 2003.
Issued in Burlington, MA on May 7, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 03-11972 Filed 5-15-03; 8:45 am]
BILLING CODE 4910-13-P