[Federal Register Volume 68, Number 130 (Tuesday, July 8, 2003)]
[Proposed Rules]
[Pages 40573-40576]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-17178]


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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: ``[email protected].'' 
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
------------------------------------------------------------------------
(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.
------------------------------------------------------------------------

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