Airworthiness Directives; General Electric Company CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 Series Turbofan Engines

[Federal Register Volume 71, Number 36 (Thursday, February 23, 2006)]
[Rules and Regulations]
[Pages 9257-9260]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 06-1594]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18648; Directorate Identifier 2004-NE-26-AD; 
Amendment 39-14494; AD 2006-04-12]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34-1A, -3A, 
-3A1, -3A2, -3B, and -3B1 Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) for General Electric Company (GE) CF34-3A1 and -3B1 series 
turbofan engines. That AD requires initial and repetitive visual 
inspections and eddy current inspections (ECIs) of certain stage 5 low 
pressure turbine (LPT) disks and stage 6 LPT disks, installed in GE 
CF34-3A1 and -3B1 series turbofan engines. Those engines are installed 
in certain Bombardier Canadair Regional Jet (RJ) airplanes. This AD 
requires the same initial and repetitive visual inspections and ECIs, 
but adds SNs to the affected disk population for RJ airplanes. This AD 
also adds GE CF34-1 and -3 series turbofan engines with certain stage 5 
and stage 6 LPT disks, to the applicability section. Those engines are 
installed in certain Bombardier Canadair Business Jet (BJ) airplanes. 
Also, this AD requires eventual replacement of the affected disks as 
terminating action to the repetitive inspections. This AD results from 
the discovery of an additional population of suspect stage 5 LPT disks 
and stage 6 LPT disks that could fail due to low-cycle fatigue cracking 
that may start at the site of an electrical arc-out on the disk. We are 
issuing this AD to prevent low-cycle-fatigue (LCF) failure of stage 5 
LPT disks and stage 6 LPT disks, which could lead to uncontained engine 
failure.

DATES: This AD becomes effective March 30, 2006. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of March 30, 2006.

ADDRESSES: You can get the service information identified in this AD 
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.
    You may examine the AD docket on the Internet at http://dms.dot.gov 
or in Room PL-401 on the plaza level of the Nassif Building, 400 
Seventh Street, SW., Washington, DC.

FOR FURTHER INFORMATION CONTACT: Tara Fitzgerald, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7130; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR part 39 
with a proposed airworthiness directive (AD). The proposed AD applies 
to GE CF34-1A, -3A, -3A1, -3A2, -3B, and -3B1 series turbofan engines. 
We published the proposed AD in the Federal Register on September 1, 
2005 (70 FR 52043). That action proposed to require the same initial 
and repetitive visual inspections and ECIs as AD 2004-15-03R1, but adds 
SNs to the affected disk population for RJ airplanes. That action also 
proposed to add GE CF34-1 and -3 series turbofan engines with certain 
stage 5 and stage 6 LPT disks, installed in certain Bombardier Canadair 
BJ airplanes, to the applicability section. Also, that action requires 
eventual replacement of the affected disks as terminating action to the 
repetitive inspections.

Examining the AD Docket

    You may examine the docket that contains the AD, any comments 
received, and any final disposition in person at the Docket Management 
Facility Docket Office between 9 a.m. and 5 p.m., Monday through 
Friday, except Federal holidays. The Docket Office (telephone (800) 
647-5227) is located on the plaza level of the Department of 
Transportation Nassif Building at the street address stated in 
ADDRESSES. Comments will be available in the AD docket shortly after 
the DMS receives them.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Request To Clarify the Nine-Month Time Limit

    One commenter requests that we clarify the nine-month time limit 
imposed by compliance section paragraphs (f)(1) and (f)(2). We do not 
agree. The compliance section in the proposed AD does not contain a 
nine-month time limit. The commenter appears to have commented in 
error, on the previous AD, AD 2004-15-03R1, which does contain a nine-
month time limit.

Request To Provide Reference to Business Jet Version of Service 
Bulletin

    The same commenter states that in the compliance section, for the 
Bombardier Canadair CL600-2B19 airplane, the GE service bulletin 
referenced is for engines used in airline service (RJ). The commenter 
requests that we also provide reference to the Business Jet version of 
the GE service bulletin, so they can apply it to their Bombardier 
Canadair CL600-2B19 airplane. We do not agree. The Bombardier Canadair 
CL600-2B19 airplane is designated as an RJ airplane. We have correctly 
referenced the RJ version of the GE service bulletin in the proposed AD 
and the AD for Bombardier Canadair CL600-2B19 airplanes. The commenter 
appears to have commented in error, on the previous AD, AD 2004-15-
03R1, which does not apply to CF-34 series engines on BJ airplanes.

Conclusion

    We have carefully reviewed the available data, including the 
comments received, and determined that air safety and the public 
interest require adopting the AD as proposed.

Costs of Compliance

    About 683 GE CF34-3A1 and -3B1 series turbofan engines are 
installed on Bombardier Canadair RJ airplanes of U.S. registry. We 
estimate that 355 of those engines will be affected by this AD. About 
690 CF34-1A, -3A, -3A1, -3A2, and -3B series turbofan engines are 
installed in Bombardier Canadair BJ airplanes of U.S. registry. We 
estimate that 249 of those engines will be affected by this AD. We also 
estimate that it will take about 70 work hours per engine to perform 
the disk inspections when the LPT module is exposed in the shop, and 
about 94 work hours per engine to perform the disk inspections when the 
LPT module is forced off-

[[Page 9258]]

wing. We also estimate that the average labor rate is $65 per work 
hour. Prorated stage 5 LPT disks will cost about $42,650 (RJ), and 
$71,083 (BJ) per engine and prorated stage 6 LPT disks will cost about 
$30,110 (RJ) and $50,183 (BJ) per engine. We also estimate that about 
24 stage 5 LPT disks and about 24 stage 6 LPT disks will be found with 
the arc-out condition and require replacement. Based on these figures, 
we estimate the total cost of the AD to U.S. operators to be 
$14,409,772.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

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 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 this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under 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 at the 
address listed under ADDRESSES.

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 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 removing Amendment 39-13773 (69 FR 
50299, August 16, 2004), and by adding a new airworthiness directive, 
Amendment 39-14494, to read as follows:

2006-04-12 General Electric Company: Amendment 39-14494. Docket No. 
FAA-2004-18648; Directorate Identifier 2004-NE-26-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective March 
30, 2006.

Affected ADs

    (b) This AD supersedes AD 2004-15-03R1, Amendment 39-13773.

Applicability

    (c) This AD applies to the following two groups of engine 
models:
    (1) General Electric Company (GE) CF34-3A1 and -3B1 series 
turbofan engines with stage 5 low pressure turbine (LPT) disks, part 
number (P/N) 6078T92P01 or stage 6 LPT disks P/N 6078T89P01, or 
both, with serial numbers (SNs) listed in Figure 3 or Figure 4 of GE 
Alert Service Bulletin (ASB) No. CF34-AL S/B 72-A0173, Revision 05, 
dated May 24, 2005. These engines are installed on Bombardier 
Canadair CL600-2B19 Regional Jet (RJ) airplanes.
    (2) GE CF34-1A, -3A, -3A1, -3A2, and -3B series turbofan engines 
with stage 5 LPT disks P/N 4922T16P01, 5024T53P01, 5024T53P02, or 
6078T92P01 or stage 6 LPT disks P/Ns 4922T17P01, 5023T45P03, 
5023T45P04, or 6078T89P01, or both, with SNs listed in Figure 3 or 
Figure 4 of GE ASB No. CF34-BJ S/B 72-A0148, Revision 02, dated May 
24, 2005. These engines are installed on Bombardier Canadair Models 
CL-600-2A12 (CL-601), CL-600-2B16 (CL-601-3A), (CL-601-3R), and (CL-
604) Business Jet (BJ) airplanes.

Unsafe Condition

    (d) This AD results from the discovery of an additional 
population of suspect stage 5 LPT disks and stage 6 LPT disks that 
could fail due to low-cycle fatigue cracking that may start at the 
site of an electrical arc-out on the disk. We are issuing this AD to 
prevent low-cycle-fatigue (LCF) failure of stage 5 LPT disks and 
stage 6 LPT disks, which could lead to uncontained engine failure.

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.

Initial Inspection or Replacement

    (f) Using the compliance schedule in Table 1 of this AD, do the 
following:
    (1) For engines installed in Bombardier Canadair RJ airplanes, 
if a stage 5 LPT disk or stage 6 LPT disk listed in Figure 3 of GE 
ASB No. CF34-AL S/B 72-A0173, Revision 05, dated May 24, 2005 or 
listed in any previous issue of ASB No. CF34-AL S/B 72-A0173 did not 
complete a visual inspection and eddy current inspection (ECI) using 
paragraphs 3.C.(1) through 3.D.(2) and paragraphs 3.E. through 
3.E.(6) of the Accomplishment Instructions of that SB before June 1, 
2005, then replace that disk at the next piece-part exposure.

                      Table 1.--Compliance Schedule
------------------------------------------------------------------------
                                        Then perform the actions defined
 On the effective date of this AD, if    in paragraph (f) of this AD at
             the disk has               next piece-part exposure, not to
                                           exceed the accumulation of
------------------------------------------------------------------------
(i) 14,750 or more cycles-since-new    An additional 250 cycles-in-
 (CSN) and has not been fluorescent     service (CIS) after the
 penetrant inspected (FPI) at an        effective date of this AD.
 earlier piece-part exposure.
(ii) 14,750 or more CSN and has been   An additional 500 CIS after the
 FPI at an earlier piece-part           effective date of this AD.
 exposure.
(iii) 14,500 or more CSN but fewer     An additional 500 CIS after the
 than 14,750 CSN.                       effective date of this AD.
(iv) 14,250 or more CSN but fewer      An additional 750 CIS after the
 than 14,500 CSN.                       effective date of this AD.
(v) 13,000 or more CSN but fewer than  An additional 1,000 CIS after the
 14,250 CSN.                            effective date of this AD.
(vi) 2,500 or more CSN but fewer than  An additional 4,000 CIS after the
 13,000 CSN.                            effective date of this AD, or
                                        14,000 CSN, whichever comes
                                        first.
(vii) Fewer than 2,500 cycles-since-   6,500 CSN.
 new (CSN).
------------------------------------------------------------------------


[[Page 9259]]

    (2) For engines installed in Bombardier Canadair BJ airplanes, 
perform an initial visual inspection and ECI of stage 5 LPT disks 
and stage 6 LPT disks listed in Figure 3 of GE ASB No. CF34-BJ S/B 
72-A0148, Revision 02, dated May 24, 2005, before January 1, 2010. 
Use paragraphs 3.C.(1) through 3.D.(2) and paragraphs 3.E. through 
3.E.(6) of Accomplishment Instructions of GE ASB No. CF34-BJ S/B 72-
A0148, Revision 02, dated May 24, 2005 to do the inspections.

Repetitive Inspections

    (g) For engines installed in Bombardier Canadair RJ airplanes 
with stage 5 LPT disks and stage 6 LPT disks listed in Figure 3 of 
GE ASB No. CF34-AL S/B 72-A0173, Revision 05, dated May 24, 2005, 
that were initially visually inspected and ECI'ed before June 1, 
2005, do the following:
    (1) Perform repetitive visual inspections and ECIs within every 
3,100 cycles-since-last-inspection (CSLI), until the life limit of 
the disk is reached.
    (2) Use paragraphs 3.C.(1) through 3.D.(2) and paragraphs 3.E. 
through 3.E.(6) of Accomplishment Instructions of GE ASB No. CF34-AL 
S/B 72-A0173, Revision 05, dated May 24, 2005 to do the inspections.
    (h) For engines installed in Bombardier Canadair BJ airplanes, 
with stage 5 LPT disks and stage 6 LPT disks initially inspected as 
specified in paragraph (f)(2) of this AD, do the following:
    (1) Perform repetitive visual inspections and ECIs within every 
3,100 CSLI, until the life limit of the disk is reached.
    (2) Use paragraphs 3.C.(1) through 3.D.(2) and paragraphs 3.E. 
through 3.E.(6) of Accomplishment Instructions of GE ASB No. CF34-BJ 
S/B 72-A0148, Revision 02, dated May 24, 2005, to do the 
inspections.

Disks That Pass Inspection

    (i) Reinstall disks that pass the inspections in paragraphs (f), 
(g), and (h) of this AD into the same LPT module from which they 
were removed.

Stage 5 and Stage 6 LPT Disk Removal

    (j) Remove any disk from service if there is an arc-out found on 
that disk.
    (k) At the next piece-part exposure for engines installed in 
Bombardier Canadair RJ airplanes, remove from service stage 5 LPT 
disks and stage 6 LPT disks listed in Figure 4 of GE ASB No. CF34-AL 
S/B 72-A0173, Revision 05, dated May 24, 2005.
    (l) At the next piece-part exposure for engines installed in 
Bombardier Canadair BJ airplanes, remove from service stage 5 LPT 
disks and stage 6 LPT disks listed in Figure 4 of GE ASB No. CF34-BJ 
S/B 72-A0148 Revision 02, dated May 24, 2005.

Optional Terminating Action

    (m) Replacement of an affected stage 5 LPT disk or affected 
stage 6 LPT disk, with a disk not listed in Figure 3 or Figure 4 of 
GE ASB No. CF34-AL S/B 72-A0173 Revision 05, dated May 24, 2005 or 
not listed in Figure 3 or Figure 4 of GE ASB No. CF34-BJ S/B 72-
A0148, Revision 02, dated May 24, 2005 is terminating action to the 
repetitive inspections and removals required by this AD for that 
disk.

Terminating Action

    (n) As terminating action to the repetitive inspections and 
removals in this AD, replace all disks by January 1, 2013 that are 
listed in Figure 3 and Figure 4 of GE ASB No. CF34-AL S/B 72-A0173, 
Revision 05, dated May 24, 2005, and that are listed in Figure 3 and 
Figure 4 of GE ASB No. CF34-BJ S/B 72-A0148, Revision 02, dated May 
24, 2005.

Actions Completed per Previous Releases of Alert Service Bulletins

    (o) Actions completed before the effective date of this AD using 
GE ASB No. CF34-AL S/B 72-A0173, dated April 2, 2004; or Revision 
01, dated May 20, 2004; or Revision 02, dated June 22, 2004; or 
Revision 03, dated July 20, 2004; or Revision 04, dated February 7, 
2005; or GE ASB No. CF34-BJ S/B 72-A0148, dated September 2, 2004; 
or Revision 01, dated March 10, 2005, are considered acceptable for 
compliance with the corresponding action in this AD.

Serviceable LPT Disk Definition

    (p) For the purpose of this AD, a serviceable LPT disk is a disk 
not listed in Figure 3 or Figure 4 of GE ASB No. CF34-AL S/B 72-
A0173, Revision 05, dated May 24, 2005, or Figure 3 or Figure 4 of 
GE ASB No. CF34-BJ S/B 72-A0148, Revision 02, dated May 24, 2005.

Piece-Part Exposure Definitions

    (q) For the purpose of this AD, the definition of piece-part 
exposure for the stage 5 LPT disk is when the disk is separated from 
the forward and aft bolted joints.
    (r) For the purpose of this AD, the definition of piece-part 
exposure for the stage 6 LPT disk is when the disk is separated from 
the forward bolted joint.

Replacement Engine or Replacement LPT Module Definition

    (s) For the purpose of this AD, the definition of a replacement 
engine or replacement LPT module is an engine or LPT module that 
does not have installed any of the suspect disks listed in Figure 3 
or Figure 4 of GE ASB No. CF34-AL S/B 72-A0173 Revision 05, dated 
May 24, 2005, or Figure 3 or Figure 4 of GE ASB No. CF34-BJ S/B 72-
A0148, Revision 02, dated May 24, 2005.

Alternative Methods of Compliance

    (t) 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.

Related Information

    (u) GE ASB No. CF34-AL S/B 72-A0178 and ASB No. CF34-BJ S/B 72-
A0152 contain the information necessary to identify and inspect the 
suspect disks that are the subject of this AD.

Material Incorporated by Reference

    (v) You must use the General Electric Company service 
information specified in Table 2 of this AD to perform the actions 
required by this AD. The Director of the Federal Register approved 
the incorporation by reference of the documents listed in Table 2 of 
this AD in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. 
Contact 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, for a copy of this 
service information. You may review copies at the Docket Management 
Facility; U.S. Department of Transportation, 400 Seventh Street, 
SW., Nassif Building, Room PL-401, Washington, DC 20590-0001, on the 
internet at http://dms.dot.gov, or at the National Archives and 
Records Administration (NARA). For information on the availability 
of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

                                      Table 2.--Incorporation by Reference
----------------------------------------------------------------------------------------------------------------
        Alert Service Bulletin No.                   Page              Revision                Date
----------------------------------------------------------------------------------------------------------------
CF34-AL S/B 72-A0173, Total Pages: 37....  ALL.....................           05  May 24, 2005.
CF34-BJ S/B 72-A0148, Total Pages: 39....  ALL.....................           02  May 24, 2005.
----------------------------------------------------------------------------------------------------------------



[[Page 9260]]

    Issued in Burlington, Massachusetts, on February 14, 2006.
Ann C. Mollica,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 06-1594 Filed 2-22-06; 8:45 am]
BILLING CODE 4910-13-P

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T03:48:30.377057+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

4380fab23f8266833840b2970b3bb884d62fa8df679859772d2f9a625149d595

Text SHA-256

820ad367dbd5918c2650a623405fd27beb7a6d8ebe5364c2e45caa9ad54c2f5d