[Federal Register: July 8, 2003 (Volume 68, Number 130)]
[Proposed Rules]
[Page 40573-40576]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr08jy03-19]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2001-NE-21-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Company CF34-3A1, -3B,
and -3B1 Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The Federal Aviation Administration (FAA) proposes to revise
an existing airworthiness directive (AD) applicable to General Electric
Company (GE) CF34-3A1, -3B, and -3B1 turbofan engines with scavenge
screens part numbers (P/Ns) 4047T95P01 and 5054T86G02 installed in the
B-sump oil scavenge system. That AD currently requires initial and
repetitive visual inspections and cleaning of the B-sump scavenge
screens until a screenless fitting is installed. This proposal requires
the same initial and repetitive visual inspections and cleaning of the
B-sump scavenge screens until a screenless fitting is installed. This
proposal also corrects a typographical error, and introduces a less
restrictive terminating action schedule. This proposal is prompted by
the need to correct a typographical error and by the need to introduce
a less restrictive terminating action schedule. The actions specified
by the proposed AD are intended to prevent B-sump scavenge screen
blockage due to coking which could result in ignition of B-sump oil in
the secondary air system, fan drive shaft separation, and uncontained
engine failure.
DATES: Comments must be received by September 8, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 2001-NE-21-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at
this location, by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. Comments may also be sent via
the Internet using the following address: ``9-ane-adcomment@faa.gov.''
Comments sent via the Internet must contain the docket number in the
subject line.
The service information referenced in the proposed rule may be
obtained from GE Aircraft Engines, 1000 Western Avenue, Lynn, MA 01910;
Attention: CF34 Product Support Engineering, Mail Zone: 34017;
telephone (781) 594-6323; fax (781) 594-0600. This information may be
examined, by appointment, at the FAA, New England Region, Office of the
Regional Counsel, 12 New England Executive Park, Burlington, MA.
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:
Comments Invited
Interested persons are invited to participate in the making of the
[[Page 40574]]
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this action may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2001-NE-21-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRM's
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 2001-NE-21-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
On March 6, 2003, the FAA issued AD 2003-05-10, Amendment 39-13086
(68 FR 12806, March 18, 2003), to require initial and repetitive visual
inspections and cleaning of the B-sump scavenge screens until a
screenless fitting is installed. That action was prompted by six
reports of B-sump oil scavenge system failure causing engine in-flight
shutdowns. That condition, if not corrected, could result in ignition
of B-sump oil in the secondary air system, fan drive shaft separation,
and uncontained engine failure.
Since AD 2003-05-10 was issued, the FAA has recognized that a
typographical error needs to be corrected in the Differences Between
This AD and the Manufacturer's Service Information paragraph, and that
a less restrictive terminating action schedule needs to be established.
Manufacturer's Service Information
The FAA has reviewed and approved the technical contents of GE
Aircraft Engines (GE) Alert Service Bulletin (ASB) CF34-AL S/B 79-
A0014, Revision 3, dated January 31, 2003; and ASB CF34-BJ S/B 79-
A0015, Revision 3, dated January 31, 2003; that describe procedures for
initial and repetitive visual inspections and cleaning of the B-sump
scavenge screens. The FAA has also reviewed and approved GE ASB CF34-AL
S/B 79-A0016 and ASB CF34-BJ S/B 79-A0017, both dated June 17, 2002.
These ASBs describe the procedures for introducing the screenless B-
sump scavenge fittings and for reworking to eliminate the screens from
the existing scavenge screen fittings located at the forward and aft
end of the lube and scavenge pump assembly, thereby terminating the
repetitive inspections.
Differences Between This Proposed AD and the Manufacturer's Service
Information
GE ASB CF34-AL S/B 79-A0014, Revision 3, dated January 31, 2003,
recommends for engines with more than 4,000 hours time-since-new (TSN)
or more than 1,000 hours time-since-last-shop-visit (TSLSV), initial
visual inspections and cleaning of the B-sump scavenge screens ``by the
next A-check''. GE ASB CF34-BJ S/B 79-A0015, Revision 3, dated January
31, 2003, recommends for engines with more than 4,000 hours TSN or more
than 1,000 hours TSLSV, initial visual inspections and cleaning of the
B-sump scavenge screens within 300 hours for the CF34-3A1 engine model
or within 400 hours for the CF34-3B engine model. However, this
proposed AD would require initial visual inspections and cleaning of
the B-sump scavenge screens within 500 hours after the effective date
of this proposed AD. The time intervals have been changed from those
cited in the ASBs to provide consistency for all engine models and to
eliminate the use of aircraft maintenance terminology. The times are
approximately equivalent to the A-check intervals.
GE ASBs CF34-AL S/B 79-A0016, dated June 17, 2002; and CF34-BJ S/B
79-A0017, dated June 17, 2002; recommend for engines with more than
4,000 hours TSN or more than 1,000 hours TSLSV, replacement of existing
scavenge screens P/Ns 4047T95P01 and 5054T86G02, installed in the B-
sump oil scavenge system, with screenless fittings ``by the next A-
check''. However, this proposed AD would require installation of
screenless fittings, or fittings that have been reworked to remove the
screens, in the B-sump oil scavenge system within 500 hours after the
effective date of this proposed AD. The installation requirement has
been changed from that cited in the ASBs to eliminate the use of
aircraft maintenance terminology. The time is approximately equivalent
to the A-check interval.
FAA's Determination of an Unsafe Condition and Proposed Actions
Since an unsafe condition has been identified that is likely to
exist or develop on other GE CF34-3A1, -3B, and -3B1 turbofan engines
of the same type design, this proposed AD is being issued to prevent B-
sump scavenge screen blockage due to coking, which could result in
ignition of B-sump oil in the secondary air system, fan drive shaft
separation, and uncontained engine failure. This proposed AD would
require:
[sbull] Initial visual inspection and cleaning of the scavenge
screens, P/Ns 4047T95P01 and 5054T86G02, installed in the B-sump oil
scavenge system.
[sbull] Repetitive visual inspection and cleaning of the scavenge
screens, P/Ns 4047T95P01 and 5054T86G02, installed in the B-sump oil
scavenge system, within 200 hours time-since-last inspection (TSLI) if
no coking is found.
[sbull] Repetitive visual inspection and cleaning of the scavenge
screens, P/Ns 4047T95P01 and 5054T86G02, installed in the B-sump
scavenge system, within 100 hours TSLI if any coking is found.
[sbull] Replacement of existing scavenge screens, P/Ns 4047T95P01
and 5054T86G02, installed in the B-sump oil scavenge system, with
screenless fittings.
The actions must be done in accordance with the service bulletins
described previously.
Economic Analysis
There are approximately 940 engines of the affected design in the
worldwide fleet. The FAA estimates that 576 engines installed on
aircraft of U.S. registry would be affected by this proposed AD. The
FAA also estimates that it would take approximately 10.0 work hours per
engine to perform the proposed actions, and that the average labor rate
is $65 per work hour. Required parts would cost approximately $1,050
per engine. Based on these figures, the total cost of the proposed AD
to U.S. operators is estimated to be $979,200.
Regulatory Analysis
This proposed rule does not have federalism implications, as
defined in Executive Order 13132, because it
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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 proposed rule.
For the reasons discussed above, I certify that this 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) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action 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, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 removing Amendment 39-13086 (68 FR
12806, March 18, 2003), and by adding a new airworthiness directive, to
read as follows:
General Electric Company: Docket No. 2001-NE-21-AD. Revises AD 2003-
05-10, Amendment 39-13086.
Applicability: This airworthiness directive (AD) is applicable
to General Electric Company (GE) CF34-3A1, -3B, and -3B1 turbofan
engines with scavenge screens part numbers (P/Ns) 4047T95P01 and
5054T86G02 installed in the B-sump oil scavenge system. These
engines are installed on, but not limited to, Bombardier Inc.
(Canadair) Model CL-600-2A12, CL-600-2B16, and CL-600-2B19
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 (d) 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 B-sump scavenge screen blockage due to coking, which
could result in ignition of B-sump oil in the secondary air system,
fan drive shaft separation, and uncontained engine failure, do the
following:
Initial Inspection and Cleaning of B-Sump Screens
(a) Perform an initial visual inspection and cleaning of
scavenge screens, P/Ns 4047T95P01 and 5054T86G02, installed in the
B-sump oil scavenge system, in accordance with Paragraphs 3A through
3B of the Accomplishment Instructions of GE Aircraft Engines (GE)
Alert Service Bulletin (ASB) CF34-AL S/B 79-A0014, Revision 3, dated
January 31, 2003; or ASB CF34-BJ S/B 79-A0015, Revision 3, dated
January 31, 2003; and the following table:
Initial Inspection and Cleaning Schedule
------------------------------------------------------------------------
Engine hours time-since-new (TSN) or time-
since-last-shop-visit (TSLSV) Inspect and clean
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(1) Fewer than 4,000 hours TSN or fewer than Before 4,000 hours TSN or
4,000 hours TSLSV if it can be confirmed TSLSV.
that both the B-sump scavenge screens were
cleaned and the B-sump and combustor frame
(strut tubes) were removed from the engine
and cleaned at that prior shop visit.
(2) Fewer than 1,000 hours TSLSV if it can Before 1,000 hours TSLSV.
NOT be confirmed that both the B-sump
scavenge screens were cleaned and the B-sump
and combustor frame (strut tubes) were
removed from the engine and cleaned at that
prior shop visit.
(3) 4,000 hours or greater TSN or 4,000 hours Within 500 hours time-in-
or greater TSLSV if it can be confirmed that service (TIS) after the
both the B-sump scavenge screens were effective date of this
cleaned and the B-sump and combustor frame AD.
(strut tubes) were removed from the engine
and cleaned at that prior shop visit, or
1,000 hours or greater TSLSV if it can NOT
be confirmed that both the B-sump scavenge
screens were cleaned and the B-sump and
combustor frame (strut tubes) were removed
from the engine and cleaned at that prior
shop visit.
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Repetitive Inspections and Cleaning
(b) Perform repetitive visual inspections and cleaning of
scavenge screens, P/Ns 4047T95P01 and 5054T86G02, installed in the
B-sump oil scavenge system, in accordance with Paragraphs 3A through
3B of the Accomplishment Instructions of GE ASB CF34-AL S/B 79-
A0014, Revision 3, dated January 31, 2003; and ASB CF34-BJ S/B 79-
A0015, Revision 3, dated January 31, 2003; and the following:
(1) At intervals not to exceed 200 hours time-since-last-
inspection (TSLI), if no coke is found in screens during initial or
any prior inspections, or
(2) At intervals not to exceed 100 hours TSLI, if coke is found
in screens during initial or any prior inspections.
Terminating Actions
(c) Install new screenless fittings or fittings that have been
reworked to remove the screens, in the B-sump oil scavenge system,
in accordance with GE ASB CF34-AL S/B 79-A0016, dated June 17, 2002;
or ASB CF34-BJ S/B 79-A0017, dated June 17, 2002, and the following
schedule:
(1) For engines with more than 4,000 hours TSN, within 500 hours
TIS after the effective date of the AD, or within 1,000 hours TSLSV,
whichever occurs first.
(2) For engines with less than or equal to 4,000 hours TSN,
prior to 4,500 hours TSN.
This constitutes terminating action to the inspections required
in paragraph (b) of this AD.
Alternative Methods of Compliance
(d) 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.
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Special Flight Permits
(e) Special flight permits may be issued in accordance with
Sec. Sec. 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 done.
Issued in Burlington, Massachusetts, on June 30, 2003.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 03-17178 Filed 7-7-03; 8:45 am]
BILLING CODE 4910-13-P