[Federal Register: March 20, 2003 (Volume 68, Number 54)]
[Rules and Regulations]               
[Page 13618-13619]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20mr03-3]                         

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-48-AD; Amendment 39-13090; AD 2003-06-03]
RIN 2120-AA64

 
Airworthiness Directives; General Electric Aircraft Engines CT7 
Series Turboprop Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain General Electric Aircraft Engines (GEAE) CT7 
series turboprop engines. This amendment requires initial and 
repetitive inspections of the propeller gearbox (PGB) oil filter 
impending bypass button (IBB) for extension (popping), requires 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, this 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. This amendment is 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. The actions specified by this AD are intended 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: Effective April 24, 2003. The incorporation by reference of 
certain publications listed in the regulations is approved by the 
Director of the Federal Register as of April 24, 2003.

ADDRESSES: The service information referenced in this AD may be 
obtained from General Electric Aircraft Engines CT7 Series Turboprop 
Engines, 1000 Western Ave, Lynn, MA 01910; telephone (781) 594-3140, 
fax (781) 594-4805. This information may be examined, by appointment, 
at the Federal Aviation Administration (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: Barbara Caufield, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7146; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an AD that is 
applicable to certain GEAE CT7 series turboprop engines was published 
in the Federal Register on June 13, 2002 (67 FR 40623). That action 
proposed to require initial and repetitive inspections of the PGB oil 
filter IBB for extension (popping), 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 action proposed to require 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 in accordance 
with GEAE CT7 Turboprop Service Bulletin CT7-TP S/B 72-0453, dated July 
27, 2001 and GEAE CT7 Turboprop Service Bulletin CT7-TP S/B 72-0452, 
dated July 27, 2001.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were received on the 
proposal or the FAA's determination of the cost to the public. The FAA 
has determined that air safety and the public interest require the 
adoption of the rule as proposed.

Economic Analysis

    There are approximately 150 engines of the affected design 
installed on airplanes of U.S. registry that would be affected by this 
AD. The FAA estimates that each IBB inspection would take approximately 
0.25 work hours per engine, and the average labor rate is $60 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. 
Replacement of a PGB would take approximately 48 hours. Therefore, the 
total cost of the AD to U.S. operators would be approximately 
$21,138,750.

Regulatory Analysis

    This final rule does not have federalism implications, as defined 
in Executive Order 13132, because it 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. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this final rule.
    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 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. A final evaluation has been prepared for this action 
and it is contained 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, 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:

[[Page 13619]]

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 
to read as follows:

2003-06-03 General Electric Aircraft Engines: Amendment 39-13090. 
Docket No. 99-NE-48-AD.
    Applicability: This airworthiness directive (AD) is applicable 
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 CT7-TP S/B 
72-0452, dated July 27, 2001. These engines are installed on but not 
limited to SAAB 340 series airplanes.

    Note 1: This AD applies to each engine 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 engines 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 (f) 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: Compliance with this AD is required as indicated, 
unless already done.
    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, do the 
following:
    (a) Inspect the PGB oil filter impending bypass button (IBB) for 
extension in accordance with 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.
    (b) If the PGB oil filter IBB is extended, replace the oil 
filter and perform follow-on inspections in accordance with 3.A of 
the Accomplishment Instructions of GEAE CT7 Turboprop Service 
Bulletin CT7-TP S/B 72-0453, dated July 27, 2001.
    (c) 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 in accordance with the Accomplishment 
Instructions of GEAE CT7 Turboprop Service Bulletin CT7-TP S/B 72-
0452, dated July 27, 2001.
    (d) 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 Service Bulletin CT7-TP S/B 72-0452, dated July 27, 2001, 
replace the PGB before accumulating an additional 2,000 engine 
flight hours after the effective date of this AD.

Terminating Action

    (e) Replacement of left-hand and right-hand idler gears in 
accordance with paragraph (c) of this AD, or replacement of the PGB 
in accordance with paragraph (d) of this AD constitutes terminating 
action to the repetitive inspections required by paragraph (a) of 
this AD.

Alternative Methods of Compliance

    (f) 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, Engine Certification Office (ECO). 
Operators must submit their request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Special Flight Permits

    (g) Special flight permits may be issued only for an airplane 
that has not more than one engine with a PGB oil filter IBB 
extended, to operate the airplane to a location where the 
requirements of this AD can be done.

Documents That Have Been Incorporated By Reference

    (h) The inspections must be done in accordance with the 
following General Electric Aircraft Engines service bulletins (SBs):

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         Document No.             Pages     Revision          Date
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SB CT7-TP S/B 72-0452 Total     All.....  Original...  July 27, 2001
 Pages: 12.
SB CT7-TP S/B 72-0453 Total     All.....  Original...  July 27, 2001
 Pages: 5.
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    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 General Electric Aircraft 
Engines CT7 Series Turboprop Engines, 1000 Western Ave, Lynn, MA 
01910; telephone (781) 594-3140, fax (781) 594-4805. Copies may be 
inspected 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.

Effective Date

    (i) This amendment becomes effective on April 24, 2003.


    Issued in Burlington, Massachusetts, on March 12, 2003.
Mark C. Fulmer,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 03-6505 Filed 3-19-03; 8:45 am]

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