Airworthiness Directives; CFM International (CFMI) Model CFM56-7B Turbofan Engines

[Federal Register Volume 66, Number 20 (Tuesday, January 30, 2001)]
[Rules and Regulations]
[Pages 8165-8167]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-2610]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-03-AD; Amendment 39-12097; AD 2001-02-12]
RIN 2120-AA64


Airworthiness Directives; CFM International (CFMI) Model CFM56-7B 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to CFMI model CFM56-7B turbofan engines. This action 
requires a one-time on-wing torque inspection, and torque if needed, of 
all the PS3 pressure line fittings to insure proper torque. This 
amendment is prompted by service events which resulted in two in-flight 
shutdowns (IFSD's) and an aborted takeoff due to the disconnection of 
one of the PS3 line fittings. The actions specified in this AD are 
intended to prevent air leakage from incorrectly torqued fittings of 
the PS3 line, which could result in engine power loss.

DATES: Effective February 14, 2001.
    Comments for inclusion in the Rules Docket must be received on or 
before April 2, 2001.

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-03-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. 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.

FOR FURTHER INFORMATION CONTACT: Diane Cook, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone 781-238-
7133, fax 781-238-7199.

SUPPLEMENTARY INFORMATION: The FAA has received reports of two in-
flight shutdowns and one aborted take-off on three different Boeing 
737NG airplanes powered by CFM56-7B turbofan engines. In all of these 
cases, the engine rolled back to idle speed and would not accelerate. 
The investigation revealed that the PS3 pressure line B-nut fitting at 
the 6 o'clock position had disconnected in two of these events and the 
PS3 pressure B-nut fitting at the combustion case port location had 
disconnected in the third event. An operator, involved in one of the 
IFSD events, completed on-wing torque inspections of the PS3 pressure 
line fittings of its CFMI CFM56-7B fleet. As a result of these 
inspections, one engine was found with a loose B-nut fitting at the 6 
o'clock location and two engines were found with loose cap fittings at 
the 6 o'clock location. The two engines with loose caps were on the 
same airplane. The investigation also initiated PS3 pressure line 
fitting torque inspections on 10 engines that were on Boeing's flight 
line. These inspections revealed one engine with a loose B-nut fitting 
at the 6 o'clock position and one engine with a loose cap fitting at 
the 6 o'clock position. General Electric and SNECMA also inspected 
CFM56-7B engines that were in assembly. No loose fittings were found. 
The investigation to determine the cause of the loose PS3 pressure line 
fittings continues. Action to insure correct torque of these fittings 
on current production engines has been initiated by adding a new torque 
inspection requirement for the PS3 pressure line fittings at the end of 
the main engine assembly process. However, based on the inspection 
results indicated above, it has been determined that mandating action 
on in-service engines to ensure that the PS3 pressure line fittings are 
correctly torqued is required.

Requirements of This AD

    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of the same

[[Page 8166]]

type design, this AD is being issued to prevent air leakage from 
incorrectly torqued fittings of the PS3 line, which could result in 
engine power loss.
    This AD requires a one-time, on-wing torque inspection of all the 
PS3 pressure line fittings to insure correct torque and, if necessary, 
torquing of those fittings to their correct value within 25 days after 
the effective date of this AD.

Immediate Adoption of This AD

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the 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 that 
summarizes each FAA-public contact concerned with the substance of this 
AD 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-03-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    This proposed rule 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 proposed rule.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and is not a ``significant regulatory action'' 
under Executive Order 12866. It has been determined further that this 
action involves an emergency regulation under DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979). If it is determined 
that this emergency regulation otherwise would be significant under DOT 
Regulatory Policies and Procedures, a final regulatory evaluation will 
be prepared and placed in the Rules Docket. A copy of it, if filed, 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 adding the following new 
airworthiness directive:

2001-02-12  CFM International: Amendment 39-12097. Docket No. 2001-
NE-03-AD.

Applicability

    This airworthiness directive (AD) is applicable to all CFM 
International (CFMI) model CFM56-7B turbofan engines except for 
engines with serial numbers DAC 876-747 and higher, and SAC 888-XXX 
and 889-XXX: 166-168, 172-173, 175-178, 180 and higher. These 
engines are installed on, but not limited to, Boeing 737NG 
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 (b) 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 within 25 days after the 
effective date of this AD, unless already done.
    To prevent air leakage from incorrectly torqued fittings of the 
PS3 pressure line, which could result in engine power loss, do the 
following:
    (a) Check for and apply the correct torque in the tightening 
direction of all PS3 pressure line fittings as identified in Figure 
1 of this AD as Joint 1, Joint 2, Joint 3, Joint 4, Joint 5, and 
Joint 6 as follows:

    Note 2: CFM International Service Bulletin, CFM56-7B S/B 75-
0005, dated January 22, 2001, and the CFM56 Standard Practice 
Manual, CFMI-TP.SP.2, contain information on torquing the PS3 
pressure line fittings, including supporting the pressure line from 
countertorque.

    (1) Torque Joint 1 to ensure a torque value of 140 inch-pounds.
    (2) Due to accessibility limitations, check Joint 2 for finger 
looseness, and only if loose, torque to a value of 285 inch-pounds.
    (3) Torque Joint 3, Joint 5, and Joint 6 to ensure a torque 
value of 285 inch-pounds.
    (4) Torque Joint 4 to ensure a torque value of 100 inch-pounds.

[[Page 8167]]

[GRAPHIC] [TIFF OMITTED] TR30JA01.000

Alternative Methods of Compliance

    (b) 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, who may add comments and then send 
it to the Manager, ECO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Special Flight Permits

    (c) Special flight permits may be issued in accordance with 
Secs. 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.

Effective Date of This AD

    (d) This amendment becomes effective on February 14, 2001.

    Issued in Burlington, Massachusetts, on January 23, 2001.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller, Directorate, Aircraft 
Certification Service.
[FR Doc. 01-2610 Filed 1-29-01; 8:45 am]
BILLING CODE 4910-13-P

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