[Federal Register: June 21, 2002 (Volume 67, Number 120)]
[Proposed Rules]               
[Page 42202-42204]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr21jn02-12]                         

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NE-09-AD]
RIN 2120-AA64

 
Airworthiness Directives: General Electric Company CF6-80A1/A3 
and CF6-80C2A PMC Series Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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

SUMMARY: The Federal Aviation Administration (FAA) proposes to adopt a 
new airworthiness directive (AD) that is applicable to General Electric 
Company (GE) CF6-80A1/A3 and CF6-80C2A PMC series turbofan engines. 
This proposal would require performing either a Directional Pilot Valve 
(DPV) pressure switch moisture purge procedure and an operational check 
of the fan reverser or replacing the DPV assembly with a serviceable 
assembly and performing an operational check of the fan reverser. 
Thereafter, this AD would require one of these actions on a repetitive 
basis. This proposal is prompted by a review of fan reverser safety 
analyses resulting from the discovery of an undetectable failure mode 
of the DPV pressure switch on certain GE CF6-80C2A and CF6-80A engine 
models. The actions specified in the proposed AD are intended to 
prevent inadvertent fan reverser deployment, which, if it occurred in-
flight, could result in loss of control of the airplane.

DATES: Comments must be received by August 20, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 2002-NE-09-AD, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location, by appointment, between 8:00 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. Comments may also be sent via 
the Internet using the following address: ``9-ane-adcomment@faa.gov''. 
Comments sent via the Internet must contain the docket number in the 
subject line.
    The service information referenced in the proposed rule may be 
obtained from Middle River Aircraft Systems, Mail Point 46, 103 
Chesapeake Park Plaza, Baltimore, MD, 21220-4295, telephone: (410) 682-
0094, fax: (410) 682-0100. This information may be examined, by 
appointment, at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Ann C. Mollica, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park; Burlington, MA, 01803; telephone (781) 238-
7740; 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 in triplicate 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 action 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 action must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 2002-NE-09-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRM's

    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. 2002-NE-09-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    The FAA received a report of inadvertent thrust reverser deployment 
on a Pratt & Whitney powered Airbus Industrie A300-600 series airplane. 
Following that event, the FAA reviewed thrust reverser safety analyses 
on other

[[Page 42203]]

make and model engines, including GE CF6-80A1/A3 and CF6-80C2A series 
turbofan engines. The thrust reverser is also known as the fan reverser 
on these engine models. A review of the thrust reverser actuation 
system (TRAS) component failure analyses and system safety analyses 
revealed that hidden failure modes involving the DPV assembly can 
exist, and an inadvertent deployment of the fan reverser could occur as 
a result.
    The FAA had received reports of DPV pressure switch failures on 
several GE CF6-80 engines as early as 1998. Results of an investigation 
into the root cause of these events indicates that freezing of 
accumulated moisture within the switch prevented normal functioning of 
the switch. Under certain circumstances, ice formation within the 
pressure switch does not allow an internal spring to unload, and 
therefore results in a switch failure. When the pressure switch fails 
to actuate, it will erroneously indicate the TRAS is not pressurized, 
when it in fact is pressurized. These failures are not detectable in 
certain CF6-80A and CF6-80C2A engine models.
    The DPV assembly controls the direction of the operation of the 
center drive unit when the TRAS is activated. High pressure downstream 
of the pressure regulating and shutoff valve (PRSOV) can be caused by 
auto restow, PRSOV open failures, or significant PRSOV leakage. The DPV 
pressure switch is used to detect PRSOV open failures and significant 
PRSOV leakage. If high pressure downstream of the PRSOV exists in 
combination with an undetected DPV pressure switch failure to actuate 
condition, an inadvertent deployment of the fan reverser could occur.
    The FAA reviewed the system safety analysis with respect to the 
impact of the DPV pressure switch component failure rate and 
detectability of this failure mode. The FAA found that for certain CF6-
80C2A and CF6-80A engine series, if this condition of switch freezing 
is not corrected, an inadvertent deployment could occur in-flight, and 
could result in loss of control of the airplane.

Manufacturer's Service Information

    The FAA has reviewed and approved the technical contents of Middle 
River Aircraft Systems Alert Service Bulletin (ASB) CF6-80A1/A3 SB 
78A4030, dated April 4, 2002, applicable to GE CF6-80A1/A3 series 
engines, and ASB CF6-80C2A PMC SB 78A1118, dated April 4, 2002, 
applicable to GE CF6-80C2A series engines, that describe procedures for 
DPV pressure switch moisture purges, and refer to applicable manuals 
which describe the replacement of the DPV assembly.

FAA's Determination of an Unsafe Condition and Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other GE CF6-80A1/A3 and CF6-80C2A PMC series 
turbofan engines of the same type design, this amendment is being 
proposed to prevent inadvertent fan reverser deployment. The proposed 
AD would require one of the following within 1,400 flight hours time-
since-new (TSN) or 600 flight hours time in service (TIS) after the 
effective date of this AD, whichever occurs later:
    (1) Performing the DPV pressure switch moisture purge procedure, 
and performing an operational check of the fan reverser; or
    (2) Replacing the DPV assembly with a serviceable assembly and 
performing an operational check of the fan reverser.

Thereafter, this proposed AD would require one of these actions at 
intervals not to exceed 1,400 flight hours TIS since the last DPV 
pressure switch of the same type design moisture purge. The actions 
would be required to be done in accordance with the service bulletin 
described previously.

Economic Analysis

    There are approximately 678 GE CF6-80A1/A3 and CF6-80C2A PMC series 
turbofan engines of the affected design in the worldwide fleet. The FAA 
estimates that 120 engines installed on airplanes of U.S. registry 
would be affected by this proposed AD. The FAA also estimates that it 
would take approximately 0.5 work hour per engine to purge the pressure 
switch and conduct an operational check and 0.5 work hour per engine to 
replace the DPV assembly and conduct an operational check. 
Approximately 5 percent of the fleet is expected to have the DPV 
assembly replaced instead of purging the DPV pressure switch each year. 
The average labor rate is $60 per work hour. Required parts to replace 
the DPV assembly would cost approximately $11,733 per engine.
    At 1,400 hour intervals, based on an annual utilization rate of 
1,600 hours, approximately 58 DPV purges or replacements will occur per 
year for CF6-80A1/A3 engines installed on US-operated A310 airplanes. 
Based on the 5 percent expectation, 55 purges will occur and three 
replacements will occur.
    At 1,400 hour intervals, based on an annual utilization rate of 
2,600 hours, approximately 130 DPV purges will occur per year for the 
CF6-80C2 PMC engines installed on US-operated A300-600 PMC airplanes. 
Based on the 5 percent expectation, 123 purges will occur and seven 
replacements will occur.
    There are no US-operated A310 airplanes with CF6-80C2 PMC engines.
    Based on these figures, the total yearly cost of the proposed AD on 
U.S. operators is estimated to be: $5,640 for labor and $117,330 for 
parts for a total cost of $122,970 per year.

Regulatory Analysis

    This proposed 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 proposed rule.
    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:

General Electric Company: Docket No. 2002-NE-09-AD.

[[Page 42204]]

Applicability

    This airworthiness directive (AD) is applicable to General 
Electric Company (GE) CF6-80A1/A3 and CF6-80C2A PMC series turbofan 
engines. These engines are installed on, but not limited to Airbus 
Industrie A300-600 and A310 series 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 (j) 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 as indicated, unless already 
done.
    To prevent inadvertent fan reverser deployment, which, if it 
occurred in-flight, could result in loss of control of the airplane, 
do the following:

GE CF6-80A1/A3  Series Engines

    (a) For GE CF6-80A1/A3 series engines, perform one of the 
following no later than 1,400 flight hours time-since-new (TSN) or 
600 flight hours time-in-service (TIS) after the effective date of 
this AD, whichever occurs later:
    (1) Perform the directional pilot valve (DPV) pressure switch 
moisture purge, in accordance with Paragraph 3.C. of the 
Accomplishment Instructions of Middle River Aircraft Systems Alert 
Service Bulletin (ASB) CF6-80A1/A3 SB 78A4030, dated April 4, 2002, 
or
    (2) Replace the DPV assembly with a serviceable assembly.
    (b) After each purge or replacement done in accordance with 
paragraphs (a)(1) or (a)(2) of this AD, perform an operational check 
of the fan reverser in accordance with Paragraph 3.E. of the 
Accomplishment Instructions of ASB CF6-80A1/A3 SB 78A4030, dated 
April 4, 2002.
    (c) Thereafter, for GE CF6-80A1/A3 series engines, at intervals 
not to exceed 1,400 hours TIS since the last pressure switch purge 
or replacement of the DPV assembly, perform one of the following:
    (1) Perform the DPV pressure switch moisture purge, in 
accordance with Paragraph 3.C. of the Accomplishment Instructions of 
Middle River Aircraft Systems ASB CF6-80A1/A3 SB 78A4030, dated 
April 4, 2002, or
    (2) Replace the DPV assembly with a serviceable assembly.
    (d) After each purge or replacement done in accordance with 
paragraphs (c)(1) or (c)(2) of this AD, perform an operational check 
of the fan reverser in accordance with Paragraph 3.E. of the 
Accomplishment Instructions of ASB CF6-80A1/A3 SB 78A4030, dated 
April 4, 2002.

GE CF6-80C2A  Series Engines

    (e) For GE CF6-80C2A1/A2/A3/A5/A8 series engines, perform one of 
the following no later than 1,400 flight hours TSN or 600 flight 
hours TIS after the effective date of this AD, whichever occurs 
later:
    (1) Perform the DPV pressure switch moisture purge, in 
accordance with Paragraph 3.C. of the Accomplishment Instructions of 
Middle River Aircraft Systems ASB CF6-80C2A PMC SB 78A1118, dated 
April 4, 2002, or
    (2) Replace the DPV assembly with a serviceable assembly.
    (f) After each purge or replacement done in accordance with 
paragraphs (e)(1) or (e)(2) of this AD, perform an operational check 
of the fan reverser, in accordance with Paragraph 3.E. of the 
Accomplishment Instructions ASB CF6-80C2A PMC SB 78A1118, dated 
April 4, 2002, 2002.
    (g) Thereafter, for GE CF6-80C2A1/A2/A3/A5/A8 series engines, 
perform one of the following at intervals not to exceed 1,400 hours 
TIS since the last pressure switch purge or replacement of the DPV 
assembly:
    (1) Perform the DPV pressure switch moisture purge, in 
accordance with Paragraph 3.C. of the Accomplishment Instructions of 
Middle River Aircraft Systems ASB CF6-80C2A PMC SB 78A1118, dated 
April 4, 2002, or
    (2) Replace the DPV assembly with a serviceable assembly.
    (h) After each purge or replacement done in accordance with 
paragraphs (g)(1) or (g)(2) of this AD, perform an operational check 
of the fan reverser, in accordance with Paragraph 3.E. of the 
Accomplishment Instructions of ASB CF6-80C2A PMC SB 78A1118, dated 
April 4, 2002.

Serviceable DPV Assembly

    (i) For the purpose of this AD, a serviceable DPV assembly is an 
assembly that has:
    (1) Accumulated zero time since new, or
    (2) Passed the tests in the Middle River Aircraft Systems 
Component Maintenance Manual GEK 85007 (78-31-51), Revision No. 7 or 
later, Directional Pilot Solenoid Valve, Page Block 101, Testing and 
Troubleshooting, and that has zero flight hours TIS since passing 
the tests, or
    (3) Been successfully purged according to paragraphs (a)(1), (c) 
(1), (e)(1) or (g)(1) of this AD immediately before installation on 
the fan reverser.

Alternative Methods of Compliance

    (j) 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 must submit their request through an appropriate FAA 
Principal Maintenance Inspector, 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 airworthiness directive, 
if any, may be obtained from the ECO.

Special Flight Permits

    (k) 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 airplane to a location where the 
requirements of this AD can be done.

    Issued in Burlington, Massachusetts, on June 14, 2002.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 02-15642 Filed 6-20-02; 8:45 am]
BILLING CODE 4910-13-P