AD Amdt-39-12228

final rule

Airworthiness Directives; General Electric Company CF34 Series Turbofan Engines

AD Number
Amdt-39-12228
Status
final_rule
Effective Date
Product Category
engine
Docket
Docket No. 99-NE-49-AD
FR Citation
66 FR 26787
Technical illustration of an aircraft turbine engine assembly
Problem area Engine

Applicability

TypeManufacturerModelDetails
engine General Electric Company CF34 Series Airworthiness Directives; General Electric Company CF34 Series Turbofan Engines

Unsafe Condition

Critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane.

AI-generated summary from the source AD text. Verify against the official source before acting.

Required Actions

Revise the CF34 Engine Maintenance Program to include mandatory inspections for specific parts at each piece-part exposure, as detailed in Table 804. Inspections must be performed using the specified methods (Fluorescent Penetrant Inspection or Eddy Current Inspection) for the listed parts and areas.

AI-generated summary from the source AD text. Verify against the official source before acting.

Compliance Time

Within 30 days after the effective date of this AD.

AI-generated summary from the source AD text. Verify against the official source before acting.

Affected Aircraft

General Electric Company CF34-3A1 and -3B1 series turbofan engines, installed on but not limited to Bombardier Canadair CL 600-2B19(RJ) aircraft.

AI-generated summary from the source AD text. Verify against the official source before acting.

Federal Register Abstract

This amendment revises an existing airworthiness directive (AD), applicable to General Electric Company CF34 series turbofan engines, that currently requires revisions to the Engine Maintenance Program specified in the manufacturer's Instructions for Continued Airworthiness (ICA) for General Electric Company (GE) CF34 series turbofan engines. Those revisions require enhanced inspection of selected critical life-limited parts at each piece-part exposure. The existing AD also requires that an air carrier's approved continuous airworthiness maintenance program incorporate these inspection procedures. This amendment removes inspection requirements for parts removed from engines mounted on-wing. This amendment is prompted by the high removal rate and subsequent piece-part exposure of fan disks due to certain maintenance procedures. This additional exposure has resulted in fan disk focused inspection rates that exceed the intent of the focused inspection initiative. The actions specified by this AD are intended to prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane.

Document Text

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[Federal Register Volume 66, Number 94 (Tuesday, May 15, 2001)]
[Rules and Regulations]
[Pages 26787-26789]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-12005]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-49-AD; Amendment 39-12228; AD 2000-03-03 R1]
RIN 2120-AA64


Airworthiness Directives; General Electric Company CF34 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment revises an existing airworthiness directive 
(AD), applicable to General Electric Company CF34 series turbofan 
engines, that currently requires revisions to the Engine Maintenance 
Program specified in the manufacturer's Instructions for Continued 
Airworthiness (ICA) for General Electric Company (GE) CF34 series 
turbofan engines. Those revisions require enhanced inspection of 
selected critical life-limited parts at each piece-part exposure. The 
existing AD also requires that an air carrier's approved continuous 
airworthiness maintenance program incorporate these inspection 
procedures. This amendment removes inspection requirements for parts 
removed from engines mounted on-wing. This amendment is prompted by the 
high removal rate and subsequent piece-part exposure of fan disks due 
to certain maintenance procedures. This additional exposure has 
resulted in fan disk focused inspection rates that exceed the intent of 
the focused inspection initiative. The actions specified by this AD are 
intended to prevent critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to the 
airplane.

DATES: Effective June 19, 2001.

ADDRESSES: The information referenced in this AD 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., 
7th Floor, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Kevin Donovan, Aerospace Engineer 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7743, fax (238) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by revising AD 2000-03-03, 
Amendment 39-11560 (65 FR 5759), which is applicable to General 
Electric Company CF34 series turbofan engines, was published in the 
Federal Register on August 18, 2000 (65 FR 50468). The action removed 
inspection requirements for parts removed from engines mounted on-wing.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Change to Aircraft Model Designation

    One comment asks that the Applicability Section be changed to 
reflect the Department of Transportation (DOT) aircraft model 
designation rather than the Bombardier aircraft model designation.
    The FAA agrees. The model designation has been changed to reflect 
the DOT designation.

[[Page 26788]]

Remove ASB Reference

    A comment requests that the FAA remove the reference to Alert 
Service Bulletin (ASB) 72-A0103 contained in subparagraph (A) of the 
change to the instructions for continue airworthiness (ICA's).
    The FAA agrees. The language of the ASB has subsequently been 
incorporated into the manual cited, SEI-756, chapter 72-00-00. 
Therefore, reference to the ASB in the required change to the ICA's is 
not needed.
    After careful review of the available data, including the comments 
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.

Regulatory Impact

    This 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 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 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 
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, 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 removing Amendment 39-11560 (65 FR 
5759, February 7, 2000), and by adding a new airworthiness directive 
(AD), Amendment 39-12228 to read as follows:

2000-03-03 R1  General Electric Company: Amendment 39-12228. Docket 
99-NE-49-AD. Revises AD 2000-03-03, Amendment 39-11560.

    Applicability: General Electric Company (GE) CF34-3A1 and -3B1 
series turbofan engines, installed on but not limited to Bombardier 
Canadair CL 600-2B19(RJ) aircraft.

    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 use the authority 
provided in paragraph (c) to request approval from the FAA. This 
approval may address either no action, if the current configuration 
eliminates the unsafe condition, or different actions necessary to 
address the unsafe condition described in this AD. Such a request 
should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any engine from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to 
the airplane, accomplish the following:

Inspections

    (a) Within the next 30 days after the effective date of this AD, 
revise the CF34 Engine Maintenance Program, Chapter 5-21-00, of the 
GE CF34 Series Turbofan Engine Manual, SEI-756. For air carrier 
operations, revise the approved continuous airworthiness maintenance 
program, by adding the following:
    ``9. CF34-3A1 and CF34-3B1 Engine Maintenance Program--Mandatory 
Inspection Requirements.
    (A) This procedure is used to identify specific piece-parts that 
require mandatory inspections that must be accomplished at each 
piece-part exposure using the applicable Chapters referenced in 
Table 804 for the inspection requirements. The inspection 
requirements listed in Table 804 are not required for any piece-part 
exposure resulting when the engine remains on-wing while performing 
maintenance practice, special procedure Number 41 listed in SEI-756, 
chapter 72-00-00.
    (B) Piece-part exposure is defined as follows: Note: Fan disk 
piece-part includes the fan disk with the 56 fan pin bushings 
installed.
    (1) For engines that utilize the ``On Condition'' maintenance 
requirements: The part is considered completely disassembled to the 
piece-part level when done in accordance with the disassembly 
instructions in the GEAE authorized overhaul Engine Manual, and the 
part has accumulated more than 100 cycles-in-service since the last 
piece-part opportunity inspection, provided that the part was not 
damaged or related to the cause for its removal from the engine.
    (2) For engines that utilize the ``Hard Time'' maintenance 
requirements: The part is considered completely disassembled when 
done in accordance with the disassembly instructions used in the 
``Minor Maintenance'' or ``Overhaul'' instructions in the GEAE 
engine authorized Engine Manual, and the part has accumulated more 
than 100 cycles-in-service since the last piece-part opportunity 
inspection, provided that the part was not damaged or related to the 
cause for its removal from the engine.
    C. Refer to Table 804 below for the mandatory inspection 
requirements.

              Table 804.--Mandatory Inspection Requirements
------------------------------------------------------------------------
                                  Manual/chapter
       Part nomenclature         section/subject    Mandatory Inspection
------------------------------------------------------------------------
Fan Disk (all)................  72-21-00,          All areas (FPI); \1\
                                 INSPECTION.        Bores (ECI).\2\
Stage 1 high pressure turbine   72-46-00,          All areas (FPI); \1\
 (HPT) Rotor Disk (all).         INSPECTION.        Bores (ECI); \2\
                                                    Boltholes (ECI); \2\
                                                    Air Holes (ECI).\2\
Stage 2 HPT Rotor Disk (all)..  72-46-00,          All Areas (FPI); \1\
                                 INSPECTION.        Bores (ECI).\2\
    (a) Boltless Rim            .................  Boltholes (FPI); \1\
     Configuration.                                 Air Holes (FPI).\1\
    (b) Bolted Rim              .................  Boltholes (ECI); \2\
     Configuration.                                 Air Holes (ECI).\2\
HPT Rotor Outer Torque          72-46-00,          All areas (FPI); \1\
 Coupling (all).                 INSPECTION.        Bore (ECI) \2\
------------------------------------------------------------------------
\1\ FPI = Fluorescent Penetrant Inspection Method.
\2\ ECI = Eddy Current Inspection.``


[[Page 26789]]

    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding the provisions of section 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
shall be performed only in accordance with the CF34 Engine 
Maintenance Program, Chapter 5-21-00, of the General Electric 
Company, CF34 Series Turbofan Engine Manual, SEI-756.

Alternative Method of Compliance

    (c) 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 shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector (PMI), 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 AD, if any, may be 
obtained from the ECO.

Special Flight Permits

    (d) Special flight permits may be issued in accordance with 
sections 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.

Continuous Airworthiness Maintenance Program

    (e) FAA-certificated air carriers that have an approved 
continuous airworthiness maintenance program in accordance with the 
record keeping requirement of Sec. 121.369(c) of the Federal 
Aviation Regulations [14 CFR 121.369(c)] must maintain records of 
the mandatory inspections that result from revising the CF34 Engine 
Maintenance Program and the air carrier's continuous airworthiness 
program. Alternately, certificated air carriers may establish an 
approved system of record retention that provides a method for 
preservation and retrieval of the maintenance records that include 
the inspections resulting from this AD, and include the policy and 
procedures for implementing this alternate method in the air 
carrier's maintenance manual required by Sec. 121.369(c) of the 
Federal Aviation Regulations [14 CFR 121.369(c)]; however, the 
alternate system must be accepted by the appropriate PMI and require 
the maintenance records be maintained either indefinitely or until 
the work is repeated. Records of the piece-part inspections are not 
required under Sec. 121.380(a)(2)(vi) of the Federal Aviation 
Regulations [14 CFR 121.380(a)(2)(vi)]. All other operators must 
maintain the records of mandatory inspections required by the 
applicable regulations governing their operations.

    Note 3: The requirements of this AD have been met when the 
engine manual changes are made and air carriers have modified their 
continuous airworthiness maintenance plans to reflect the Engine 
Maintenance Program requirements specified in the GE CF34 Series 
Turbofan Engine Manual.

    This amendment becomes effective on May 30, 2001.

    Issued in Burlington, Massachusetts, on May 7, 2001.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-12005 Filed 5-14-01; 8:45 am]
BILLING CODE 4910-13-U

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