Airworthiness Directives; General Electric Aircraft Engines CF34 Series Turbofan Engines

[Federal Register Volume 64, Number 103 (Friday, May 28, 1999)]
[Rules and Regulations]
[Pages 28905-28907]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13484]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-19-AD; Amendment 39-11179; AD 99-11-08]
RIN 2120-AA64


Airworthiness Directives; General Electric Aircraft Engines CF34 
Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to General Electric Aircraft Engines (GE) CF34 series 
turbofan engines, that requires installation of a main fuel control 
(MFC) that incorporates a flange vent groove and installation of an MFC 
with improved overspeed protection. This amendment is prompted by 
reports of rapid uncommanded engine acceleration events. The actions 
specified by this AD are intended to prevent uncommanded engine 
accelerations, which could result in an engine overspeed, uncontained 
engine failure, and damage to the airplane.

DATES: Effective date: July 27, 1999. The incorporation by reference of 
certain publications listed in the regulations is approved by the 
Director of the Federal Register as of July 27, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from GEAE Technical Publications, Attention: N. Hanna MZ340M2, 
1000 Western Avenue, Lynn, MA 01910; telephone (781) 594-2906, fax 
(781) 594-0600. This information may be examined 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: Norman Brown, Controls Specialist, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7181, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to General Electric Aircraft Engines 
(GE) CF34 series turbofan engines was published in the Federal Register 
on September 18, 1998 (63 FR 49877). That action proposed to require, 
within 800 hours time in service (TIS), or 120 days after the effective 
date of this AD, whichever occurs first, installation of an MFC 
incorporating a flange vent groove. In addition, the action proposed to 
require installation of an MFC with improved overspeed protection: for 
CF34-3A1 and -3B1 series engines, installed on Canadair Regional Jet 
airplanes, within 4,000 hours TIS after the effective date of this AD, 
or 24 months after the effective date of this AD, whichever occurs 
first; and for CF34-1A, -3A, -3A1, -3A2, and -3B series engines, 
installed on Canadair Challenger airplanes, at the next hot section 
inspection, or within 60 months after the effective date of this AD, 
whichever occurs first. The actions are required to be accomplished in 
accordance with GE CF34 Alert Service Bulletin (ASB) No. A73-18, 
Revision 1, dated September 24, 1997; CF34 ASB No. A73-32, Revision 2, 
dated May 29, 1998; CF34 ASB No. A73-33, Revision 1, dated May 29, 
1998; and CF34 ASB No. A73-19, Revision 1, dated February 20, 1998.
    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.
    Since the publication of the notice of proposed rule making (NPRM), 
GE has issued Revision 2, dated May 29, 1998, to ASB A73-32 that added 
effectivity information to the Planning Information section of ASB A73-
32. GE has also issued Revision 1, dated May 29, 1998 to ASB 73-33 that 
added effectivity information to the Planning Information section of 
ASB A73-33. The ASB revisions have not affected the technical or 
economic content of this proposed AD. We have added the updated ASB 
revisions to paragraphs (a), (b)(1), and (b)(2) of the compliance 
section of this AD. GE has implemented the vent groove and improved 
overspeed protection design changes in new MFC's. In addition, we have 
made editorial changes to the compliance section of this AD to improve 
readability and to remove ambiguity. We changed the requirement ``with 
a flange vent groove reworked in accordance with'' in paragraph (a) to 
``with a flange vent groove modified in accordance with.'' We made the 
change so that you are not restricted to installing only reworked 
MFC's, and to allow you to install a new MFC with the design 
improvements. We added the base part number 6078T55 of the MFC to each 
of the P0X numbers to remove any ambiguity over the MFC's that must be 
replaced. We changed the requirement ``Install a reworked MFC with 
improved overspeed protection'' in paragraph (b) to ``Install a 
serviceable MFC with improved overspeed protection.'' We made the 
change to allow you to install a new MFC that incorporates the improved 
overspeed protection design change, and so you are not restricted to 
installing only reworked MFC's. We added the word ``within'' to the 
requirements of paragraphs (b)(1), (b)(2), and (b)(3) to allow you to 
perform the actions before reaching the specified calendar times after 
the effective date of the AD. We removed the new MFC P/N's from 
paragraphs (b)(1), (b)(2), and (b)(3) and changed ``install MFC'' to 
``install a serviceabl MFC.'' We removed the
P/N's so that you will not have to request an alternate method of 
compliance in accordance with paragraph (d) of this AD if a new MFC P/N 
is certificated for use on the applicable engines. We also added a new 
paragraph (c) that defines a serviceable MFC.
    After careful review of the available data, including the changes 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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 DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic

[[Page 28906]]

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 from 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:

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 the following new 
airworthiness directive:

99-11-08  General Electric Aircraft Engines: Amendment 39-11179. 
Docket 98-ANE-19-AD.

    Applicability: General Electric Aircraft Engines (GE) CF34-1A, 
CF34-3A, -3A1, -3A2, and CF34-3B and -3B1 series turbofan engines, 
installed on but not limited to Bombardier, Inc. Canadair airplane 
models CL-600-2A12, -2B16, and -2B19.

    Note 1: This airworthiness directive (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: Required as indicated, unless accomplished 
previously.
    To prevent uncommanded engine accelerations, which could result 
in an engine overspeed, uncontained engine failure, and damage to 
the airplane, accomplish the following:
    (a) For all CF34-3A1 -3B, and -3B1 engines, with main fuel 
control (MFC) part numbers (P/N's) 6078T55P02, 6078T55P03, 
6078T55P04, 6078T55P05, 6078T55P06, 6078T55P07, 6078T55P08, 
6078T55P09, or 6078T55P10 installed, within 800 hours time in 
service (TIS), or 120 days after the effective date of this AD, 
whichever occurs first, install an MFC with a flange vent groove 
modified in accordance with the Accomplishment Instructions of GE 
CF34 Alert Service Bulletin (ASB) No. A73-18, Revision 1, dated 
September 24, 1997, or CF34 ASB No. A73-32, Revision 1, dated 
September 24, 1997, or Revision 2, dated May 29, 1998, as 
applicable.
    (b) Install a serviceable MFC with improved overspeed protection 
as follows:
    (1) For all CF34-1A, -3A, and -3A2 series engines, install a 
serviceable MFC at the next hot section inspection, or within 60 
months after the effective date of this AD, whichever occurs first, 
in accordance with step 2A through step 2G of the Accomplishment 
Instructions of CF34 ASB No. A73-33, dated November 21, 1997, or 
Revision 1, dated May 29, 1998.
    (2) For CF34-3A1, and -3B series engines installed on Canadair 
aircraft models CL601 or CL604 (Challenger airplanes), install a 
serviceable MFC at the next hot section inspection, or within 60 
months after the effective date of this AD, whichever occurs first, 
in accordance with step 2A through step 2G of the Accomplishment 
Instructions of CF34 ASB No. A73-33, dated November 21, 1997, or 
Revision 1, dated May 29, 1998.
    (3) For CF34-3A1 and -3B1 series engines installed on Canadair 
aircraft model CL601RJ (Regional Jet airplanes), install a 
serviceable MFC within 4,000 hours TIS after the effective date of 
this AD, or within 24 months after the effective date of this AD, 
whichever occurs first, in accordance with step 2A through step 2G 
of the Accomplishment Instructions of CF34 ASB No. A73-19, Revision 
1, dated February 20, 1998.
    (c) For the purposes of this AD, a serviceable MFC is defined as 
a new MFC that incorporates the improved overspeed protection 
modifications, or an MFC that has been reworked to provide the 
improved overspeed protection as provided by the applicable GE ASB.
    (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. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Engine Certification Office.

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

    (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 accomplished.
    (f) The MFC replacement must be done in accordance with the 
following General Electric Aircraft Engines alert service bulletins:

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          Document No.                    Pages                  Revision                      Date
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A73-18.........................  All....................  1.....................  September 24, 1997.
A73-19.........................  All....................  1.....................  February 20, 1998.
A73-32.........................  All....................  1.....................  September 24, 1997.
A73-32.........................  All....................  2.....................  May 29, 1998.
A73-33.........................  All....................  Original..............  November 21, 1997.
A73-33.........................  All....................  1.....................  May 29, 1998.
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[[Page 28907]]

    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 GEAE Technical Publications, 
Attention: N. Hanna MZ340M2, 1000 Western Avenue, Lynn, MA 01910; 
telephone (781) 594-2906, fax (781) 594-0600. 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.
    (g) This amendment becomes effective on July 27, 1999.

    Issued in Burlington, Massachusetts, on May 17, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-13484 Filed 5-27-99; 8:45 am]
BILLING CODE 4910-13-P

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