[Federal Register Volume 65, Number 43 (Friday, March 3, 2000)]
[Proposed Rules]
[Pages 11505-11507]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-5012]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-57-AD]
RIN 2120-AA64


Airworthiness Directives; CFM International, S.A. CFM56-3, -3B, 
and -3C Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to CFM International, S.A. CFM56-3, -
3B, and -3C series turbofan engines. This proposal would discontinue 
use of certain lubricants no longer on the manufacturer's approved 
list. In addition, this proposal would require a one-time fan disk 
dovetail wear measurement, and if wear exceeds certain limits, require 
an ultrasonic inspection for cracks in the fan disk, and, if necessary, 
require removal from service of fan disks and replacement with 
serviceable parts. This proposal is prompted by reports of fan disk 
heavy wear and cracks. The actions specified by the proposed AD are 
intended to prevent fan disk failure, which could result in an 
uncontained engine failure and damage to the aircraft.

DATES: Comments must be received by April 3, 2000.

ADDRESSES: Submit comments to the Federal Aviation Administration 
(FAA), New England Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 98-ANE-57-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299. Comments may also be submitted to the Rules 
Docket by using the following Internet address: ``[email protected]''. Comments may be inspected at this location between 
8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.
    The service information referenced in the proposed rule may be 
obtained from CFM International, S.A., Technical Publications 
Department, 1 Neumann Way, Cincinnati, OH 45215; telephone 513-552-
2981, fax 513-552-2816. This information may be examined at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Glorianne Niebuhr, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone 781-
238-7132, fax 781-238-7199.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted 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 notice 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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-ANE-57-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    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. 98-ANE-57-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    The Federal Aviation Administration (FAA) has received reports of 
fan disk heavy wear and cracks on CFM International, S.A. CFM56-3, -3B, 
and -3C series turbofan engines. In one case, an inflight engine 
shutdown resulted from fan blade failure at the root area just above 
the pressure face. In addition, one fan disk was found cracked during a 
routine fluorescent penetrant inspection (FPI) and exhibited heavy wear 
on the pressure face. Investigation revealed high stress around the 
dovetail pressure face resulting from the use of certain fan disk 
dovetail lubricants coupled with the presence of certain fan blade/
damper configurations. This condition, if not corrected, could result 
in fan disk failure, which could result in an uncontained engine 
failure and damage to the aircraft.

Service Information

    The FAA has reviewed and approved the technical contents of CFM 
International, S.A. CFM56-3/-3B/-3C Service Bulletin (SB) No. 72-854, 
Revision 2, dated November 29, 1999, that describes procedures for the 
one-time on-wing fan disk dovetail wear measurement and fan disk 
ultrasonic inspection. This AD allows the ultrasonic inspection to be 
done on-wing or in the shop.

Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would discontinue use of certain lubricants no longer on 
the manufacturer's approved list. In addition, this proposal would 
require a one-time fan disk dovetail wear measurement, and if wear 
exceeds certain limits, require an ultrasonic inspection for cracks in 
the fan disk, and, if necessary, require removal from service of fan 
disks and replacement with serviceable parts. The compliance times are 
based upon the fan blade/damper configuration and engine thrust rating. 
The actions would be required to be accomplished in accordance with the 
SB described previously.

Economic Analysis

    There are approximately 600 engines of the affected design in the 
worldwide fleet. The FAA estimates that 510 engines installed on 
aircraft of US registry would be affected by this proposed AD, that it 
would take approximately 9 work hours per engine to accomplish the 
inspections and replacement of blades and dampers, and that the average 
labor rate is $60 per work hour. Required parts would cost 
approximately $10,700 per engine for the required fan blade/damper 
configuration. The manufacturer has informed the FAA that an estimated 
140 engines may need fan disk replacement, at $56,799 per engine. In 
addition, the FAA estimates that 159 work hours would be required to 
remove the engine from the aircraft, replace the fan disk, and return 
the engine to service. Based on these figures, the total cost impact of 
the proposed AD on US operators is estimated to be $15,019,860.

[[Page 11506]]

Regulatory Impact

    This proposal does not have federalism implications, as defined in 
Executive Order No. 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 proposal.
    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 adding the following new 
airworthiness directive:

CFM International, S.A.: Docket No. 98-ANE-57-AD.

    Applicability: CFM International, S.A (CFMI) CFM56-3, -3B, and -
3C series turbofan engines, installed on but not limited to Boeing 
737 series aircraft.

    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 (h) 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 fan disk failure, which could result in an 
uncontained engine failure and damage to the aircraft, accomplish 
the following:

Wear Measurement (Thrust Rating Category A Only)

    (a) For CFM56-3, -3B, and -3C series engines operating at the 
category A thrust rating on the effective date of this AD, that have 
never previously operated at the category B or C thrust ratings, 
perform a one time fan disk dovetail wear measurement in accordance 
with section 2.B.(1) of CFMI CFM56-3/-3B/-3C Service Bulletin (SB) 
No. 72-854, Revision 2, dated November 29, 1999, using the intervals 
defined in section 1.D.(1)(a) of the SB, and the current fan disk 
time and cycles on the effective date of the AD.

Inspection

    (1) Perform a local ultrasonic inspection for cracks in the fan 
disk in accordance with section 2.B.(2) of the SB, if required by 
the wear criteria described in section 1.D.(1)(b)1 of the SB.

Removal

    (i) Remove from service prior to further flight fan disks that 
do not meet the ultrasonic inspection criteria defined in paragraph 
2.B.(2) (d) 8b of the SB, and replace with a serviceable part.
    (ii) Remove from service within 50 cycles in service (CIS), fan 
disks that meet the ultrasonic inspection criteria defined in 
paragraph 2.B.(2) (d)8b of the SB, if the wear measurement is 
greater than or equal to 9 mils.
    (2) Install dampers, as required, in accordance with the 
compliance times and criteria described in section 1.D.(1)(b)1 of 
the SB.

Wear Measurement (Thrust Rating Category A, if the Engine Was 
Previously Operated at Thrust Rating Categories B or C)

    (b) For CFM56-3, -3B, and -3C series engines operating at the 
category A thrust rating on the effective date of this AD, that have 
previously operated at the category B or category C thrust ratings, 
perform a one-time fan disk dovetail wear measurement in accordance 
with section 2.B.(1) of CFMI CFM56-3/-3B/-3C SB No. 72-854, Revision 
2, dated November 29, 1999, using the intervals defined in section 
1.D.(1)(a) of the SB, and the current fan disk time and cycles on 
the effective date of the AD.

Inspection

    (1) Perform a local ultrasonic inspection for cracks in the fan 
disk in accordance with section 2.B.(2) of the SB, if required by 
the wear criteria described in section 1.D.(1)(b)2 of the SB.

Removal

    (i) Remove from service prior to further flight fan disks that 
do not meet the ultrasonic inspection criteria defined in paragraph 
2.B.(2)(d)8b of the SB, and replace with a serviceable part.
    (ii) Remove from service within 50 CIS, fan disks that meet the 
ultrasonic inspection criteria defined in paragraph 2.B.(2)(d)8b of 
the SB, if the wear measurement is greater than or equal to 9 mils.
    (2) Install dampers, as required, in accordance with the 
compliance times and criteria described in section 1.D.(1)(b)2 of 
the SB.

Wear Measurement (Thrust Rating Category B, Regardless of Whether the 
Engine Was Previously Operated at Thrust Rating Categories A or C)

    (c) For CFM56-3B and -3C series engines operating at the 
category B thrust rating on the effective date of this AD, 
regardless of whether the engine was previously operated at thrust 
rating categories A or C, perform a one-time fan disk dovetail wear 
measurement in accordance with section 2.B.(1) of CFMI CFM56-3/-3B/-
3C SB No. 72-854, Revision 2, dated November 29, 1999, using the 
intervals defined in section 1.D.(1)(a) of the SB, and the current 
fan disk time and cycles on the effective date of the AD.

Inspection

    (1) Perform a local ultrasonic inspection for cracks in the fan 
disk in accordance with section 2.B.(2) of the SB, if required by 
the wear criteria described in section 1.D.(1)(c) of the SB.

Removal

    (i) Remove from service prior to further flight fan disks that 
do not meet the ultrasonic inspection criteria defined in paragraph 
2.B.(2)(d)8b of the SB, and replace with a serviceable part.
    (ii) Remove from service within 50 CIS, fan disks that meet the 
ultrasonic inspection criteria defined in paragraph 2.B.(2)(d)8b of 
the SB, if the wear measurement is greater than or equal to 9 mils.
    (2) Remove and replace fan blades and install dampers, as 
required, in accordance with the compliance times and criteria 
described in section 1.D.(1)(c) of the SB.

Wear Measurement (Thrust Rating Category C, Regardless of Whether the 
Engine Was Previously Operated at Thrust Rating Categories A or B)

    (d) For CFM56-3C series engines operating at the category C 
thrust rating on the effective date of this AD, regardless of 
whether the engine was previously operated at category A or B thrust 
ratings, perform a one-time fan disk dovetail wear measurement in 
accordance with section 2.B.(1) of CFMI CFM56-3/-3B/-3C SB No. 72-
854, Revision 2, dated November 29, 1999, using the intervals 
defined in section 1.D.(1)(a) of the SB, and the current fan disk 
time and cycles on the effective date of the AD.

[[Page 11507]]

Inspection

    (1) Perform a local ultrasonic inspection for cracks in the fan 
disk in accordance with section 2.B.(2) of the SB, if required by 
the wear criteria described in section 1.D.(1)(d) of the SB.

Removal

    (i) Remove from service prior to further flight fan disks that 
do not meet the ultrasonic inspection criteria defined in paragraph 
2.B.(2)(d)8b of the SB, and replace with a serviceable part.
    (ii) Remove from service within 50 CIS, fan disks that meet the 
ultrasonic inspection criteria defined in paragraph 2.B.(2)(d)8b of 
the SB, if the wear measurement is greater than or equal to 5 mils.
    (2) [Reserved]
    (e) If the fan disk is determined to be serviceable, clean and 
lubricate the fan disk and fan blade using the instructions in 
paragraph 2.B.(2)(d)8d of the SB.

Definitions

    (f) The category A, B, and C thrust ratings listed in paragraphs 
(a) through (d) of this AD are defined in chapter 05 of the CFM56-3 
model series Engine Shop Manual, CFMI-TP.SM.5.

Lubricants

    (g) After the effective date of this AD, the following 
lubricants are no longer approved for use on the CFMI CFM56-3, -3B, 
and -3C series engines: Sandstrom 27A, ZIP D5460, Surf-kote A 1625, 
Tiolube 70 and Tiolube 75/75.

Alternative Methods of Compliance

    (h) 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 request 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.

Ferry Flights

    (i) 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 aircraft to a location where 
the requirements of this AD can be accomplished.

    Issued in Burlington, Massachusetts, on February 24, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-5012 Filed 3-2-00; 8:45 am]
BILLING CODE 4910-13-P