[Federal Register: September 8, 2003 (Volume 68, Number 173)]
[Proposed Rules]
[Page 52868-52870]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08se03-20]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NE-48-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Aircraft Engines CT7
Series Turboprop Engines
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to supersede an existing airworthiness
directive (AD) for certain General Electric Aircraft Engines (GEAE) CT7
series turboprop engines. That AD currently requires propeller gearbox
(PGB) oil filter impending bypass button (IBB) inspections, oil filter
inspections, replacement of left-hand and right-hand idler gears at
time of PGB overhaul, and replacement of certain SN PGBs before
accumulating 2,000 flight hours. This proposed AD would require the
same actions, and adds additional SNs of affected PGBs. This proposed
AD is prompted by reports of PGBs equipped with certain gears that do
not meet design specifications, resulting in the same failure addressed
in the existing AD. We are proposing this AD to prevent separation of
PGB left-hand and right-hand idler gears, which could result in
uncontained PGB failure and internal bulkhead damage, possibly
prohibiting the auxiliary feathering system from fully feathering the
propeller on certain PGBs.
DATES: We must receive any comments on this proposed AD by November 7,
2003.
ADDRESSES: Use one of the following addresses to submit comments on
this proposed AD:
[sbull] By mail: Federal Aviation Administration (FAA), New England
Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-
NE-48-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 can get the service information identified in this proposed AD
from General Electric Aircraft Engines, CT7 Series Turboprop Engines,
1000 Western Ave, Lynn, MA 01910; telephone (781) 594-3140, fax (781)
594-4805.
You may examine the AD docket at the FAA, New England Region,
Office of the Regional Counsel, 12 New England Executive Park,
Burlington, MA.
FOR FURTHER INFORMATION CONTACT: Eugene Triozzi, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (781)
238-7148; fax (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to submit any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``AD Docket No. 99-NE-48-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 proposed
AD. If a person contacts us verbally, and that contact relates to a
substantive part of this proposed 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 proposed 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 that affect you. You may get more information about
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov
Examining the AD Docket
You may examine the AD Docket (including any comments and service
information), by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. See ADDRESSES for the
location.
Discussion
On March 12, 2003, the FAA issued AD 2003-06-03 (Amendment 39-
13090, 68 FR 13618, March 20, 2003). That AD requires initial and
repetitive inspections of the PGB oil filter IBB for extension
(popping), and follow-on inspections, maintenance, and replacement
actions if the PGB oil filter IBB is popped, and if necessary,
replacement of the PGB with a serviceable PGB. In addition, that
amendment requires replacement of certain left-hand and right-hand
idler gears at time of overhaul of PGBs, and the replacement of certain
SN PGBs before accumulating 2,000 flight hours. That AD was prompted by
an on-going investigation that concluded that low-time PGB removals are
due to accelerated wear of the PGB idler gears, rather than improperly
hardened PGB input pinions. That condition, if not corrected, could
result in uncontained PGB failure and internal bulkhead damage,
possibly prohibiting the auxiliary feathering system from fully
feathering the propeller on certain PGBs.
Actions Since AD 2003-06-03 was Issued
Since that AD was issued, the FAA has learned that a certain
population of PGBs have been discovered equipped with certain gears
that do no meet design specifications. This can result in the same PGB
failure described in AD 2003-06-03.
Relevant Service Information
For AD 2003-06-03, the FAA previously reviewed and approved the
technical contents of:
[sbull] GEAE CT7 Turboprop Service Bulletin (SB) CT7-TP S/B 72-
0453, dated July 27, 2001, that describes procedures for inspections of
the PGB oil filter IBB for extension, and if the oil filter IBB is
extended, follow-on inspections, maintenance, and replacement actions.
This SB also identifies PGBs by SN that require inspection; and
[sbull] GEAE CT7 Turboprop SB CT7-TP S/B 72-0452, dated July 27,
2001, that requires replacement of certain SNs of left-hand and right-
hand idler gears
[[Page 52869]]
with serviceable gears. This SB also identifies affected PGBs by SN.
[sbull] For this proposal, the FAA has reviewed and approved the
technical contents of GEAE CT7 Turboprop Alert Service Bulletin CT7-TP
S/B 72-A0466, dated April 17, 2003, that lists the population of SNs of
PGBs susceptible to gears not meeting design specifications.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other products
of this same type design. Therefore, we are proposing this AD, which
would require:
[sbull] Initial and repetitive inspections of the propeller gearbox
(PGB) oil filter IBB for extension (popping).
[sbull] Follow-on inspections, maintenance, and replacement actions
if the PGB oil filter IBB is popped, and if necessary, replacement of
the PGB with a serviceable PGB.
[sbull] Replacement of certain left-hand and right-hand idler gears
at time of overhaul of PGBs, and the replacement of certain SN PGBs
before accumulating 2,000 flight hours after April 24, 2003, the
effective date of AD 2003-06-03.
The proposed AD would require that you do these actions using the
service information described previously.
Changes to 14 CFR Part 39--Effect on the Proposed AD
On July 10, 2002, we published a new version of 14 CFR part 39 (67
FR 47997, July 22, 2002), which governs the FAA's AD system. This
regulation now includes material that relates to altered products,
special flight permits, and alternative methods of compliance. 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.
Costs of Compliance
There are about 667 GEAE CT7 series turboprop engines of the
affected design in the worldwide fleet. We estimate that 400 engines
installed on airplanes of U.S. registry would be affected by this
proposed AD. We also estimate that each IBB inspection would take
approximately 0.25 work hours per engine, and the average labor rate is
$65 per work hour. Inspection and replacement of idler gears would take
approximately four work hours per engine at time of PGB overhaul.
Replacement cost for idler gears per PGB is estimated to be $140,670.
Therefore, the total cost on U.S. operators would be approximately
$56,378,500.
Regulatory Findings
We have determined that this proposed AD would not have federalism
implications under Executive Order 13132. This proposed AD would not
have a substantial direct effect 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.
For the reasons discussed above, I certify that the 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. Would 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 proposal 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. 99-NE-48-AD'' in your request.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, under the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend 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. The FAA amends Sec. 39.13 by removing Amendment 13090, 68 FR
13618, March 20, 2003, and by adding a new airworthiness directive,
Amendment 39-XXXXX, to read as follows:
General Electric Aircraft Engines: Docket No. 99-NE-48-AD.
Supersedes AD 2003-06-03, Amendment 39-13090.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by November 7,
2003.
Affected ADs
(b) This AD supersedes AD 2003-06-03, Amendment 39-13090.
Applicability
(c) This AD applies to General Electric Aircraft Engines (GEAE)
CT7 series turboprop engines, with propeller gearboxes (PGBs)
identified by serial number (SN) in Table 1 of GEAE CT7 Turboprop
Service Bulletin (SB) CT7-TP S/B 72-0452, dated July 27, 2001, and
Table 1 of GEAE CT7 Turboprop Alert Service Bulletin (ASB) CT7-TP S/
B 72-A0466, dated April 17, 2003. These engines are installed on but
not limited to SAAB 340 series airplanes.
Unsafe Condition
(d) This AD is prompted by reports of additional PGBs equipped
with certain gears that do not meet design specifications, resulting
in the same failure addressed in the AD being superseded. We are
issuing this AD to prevent separation of PGB left-hand and right-
hand idler gears, which could result in uncontained PGB failure and
internal bulkhead damage, possibly prohibiting the auxiliary
feathering system from fully feathering the propeller on certain
PGBs.
Compliance
(e) You are responsible for having the actions required by this
AD performed within the compliance times specified unless the
actions have already been done.
(f) Inspect the PGB oil filter impending bypass button (IBB) for
extension using the following schedule:
(1) Initially inspect within 50 hours time-in-service (TIS)
after the effective date of this AD.
(2) Thereafter, inspect each operational day.
(g) If the PGB oil filter IBB is extended, replace the oil
filter and perform follow-on inspections, using paragraph 3.A of the
Accomplishment Instructions of GEAE CT7 Turboprop SB CT7-TP S/B 72-
0453, dated July 27, 2001.
(h) At the next return of the PGB to a CT7 turboprop overhaul
facility after the effective date of this AD, replace left-hand and
right-hand idler gears. Use the Accomplishment Instructions of GEAE
CT7 Turboprop SB CT7-TP S/B 72-0452, dated July 27, 2001 to replace
the gears.
(i) If the PGB is mated to a Hamilton Standard propeller and the
left-hand and right-hand idler gears have not been replaced in
accordance with the Accomplishment Instructions of GEAE CT7
Turboprop SB CT7-TP S/B 72-0452, dated July 27, 2001, replace the
PGB before accumulating an additional 2,000 engine flight hours
after April 24, 2003, the effective date of AD 2003-06-03.
Terminating Action
(j) Replacement of left-hand and right-hand idler gears in
accordance with paragraph (h) of this AD, or replacement of the PGB
in accordance with paragraph (i) of this AD constitutes terminating
action to the repetitive inspections required by paragraph (f) of
this AD.
[[Page 52870]]
Alternative Methods of Compliance
(k) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance for this AD if
requested using the procedures found in 14 CFR 39.19.
Special Flight Permits
(l) Special flight permits may be issued only for an airplane
that does not have more than one engine with a PGB oil filter IBB
extended, to operate the airplane to allocation where the
requirements of this AD can be done.
Material Incorporated by Reference
(m) You must use the service information specified in Table 1 to
perform the inspections and replacements required by this AD.
Approval of incorporation by reference from the Office of the
Federal Register is pending for GEAE CT7 Turboprop ASB CT7-TP S/B
72-A0466, dated April 17, 2003. Table 1 follows:
Table 1.--Incorporation by Reference
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Service bulletin no. Page Revision Date
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SB CT7-TP S/B 72-0452................ ALL.................... Original............... July 27, 2001.
Total Pages: 12
SB CT7-TP S/B 72-0453................ ALL.................... Original............... July 27, 2001.
Total Pages: 5
ASB CT7-TP S/B 72-A0466.............. ALL.................... Original............... April 17, 2003.
Total Pages: 8
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Related Information
(n) None.
Issued in Burlington, Massachusetts, on September 2, 2003.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 03-22713 Filed 9-5-03; 8:45 am]
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