AD 2001-21-03

[Federal Register Volume 66, Number 204 (Monday, October 22, 2001)]
[Rules and Regulations]
[Pages 53332-53335]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 01-26324]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-62-AD; Amendment 39-12473; AD 2001-21-03]
RIN 2120-AA64


Airworthiness Directives; General Electric Company GE90 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), applicable to certain General Electric Company (GE) GE90 series 
turbofan engines. That AD currently requires inspecting and purging the 
P3B and Ps3 lines and associated fittings and ports of moisture. This 
amendment will allow the installation of improved hardware as 
terminating action to requirements of the AD, and remove the GE90-92B 
engine model from the AD applicability. This amendment is prompted by 
the recent FAA approval of redesigned P3B and Ps3 sense lines, and the 
removal of the GE90-92B engine from the applicability. The actions 
specified in this AD are intended to prevent corruption of Ps3 signals, 
which could result in simultaneous loss of thrust control of both 
engines.

DATES: Effective date November 26, 2001. The incorporation by reference 
of certain publications listed in the regulations is approved by the 
Director of the Federal Register as of November 26, 2001.

ADDRESSES: The service information referenced in this AD may be 
obtained from General Electric Company via Lockheed Martin Technology 
Services, 10525 Chester Road, Suite C, Cincinnati, OH 45215; telephone: 
(513) 672-8400, fax: (513) 672-8422. 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: John E. Golinski, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone: (781) 
238-7135; fax: (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 99-27-15, 
Amendment 39-11496 (65 FR 692, January 6, 2000), which is applicable to 
General Electric Company (GE) models GE90-76B, -77B, -85B, and -90B 
turbofan engines was published in the Federal Register on June 12, 2001 
(66 FR 31569). That action proposed to allow the installation of 
improved hardware in accordance with the Accomplishment Instructions, 
Section 3 of GE Alert Service Bulletin (ASB) No. GE90 73-A0060, 
Revision 3, dated September 14, 2000 as terminating action to 
requirements of the AD. That action also proposed to remove the GE90-
92B engine model from the AD applicability. Also, that action proposed 
an installation deadline for the improved hardware of October 31, 2001. 
The deadline is changed for this final rule to December 31, 2001, to 
support the timing for when the final rule is published in the Federal 
Register. In doing this, no additional risk to the fleet will incur, 
based on information from GE that in response to the proposal, all 
remaining engines are now retrofitted with redesigned hardware.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Remove Reference to P3B Signal Blockage From Unsafe Condition 
Description

    One comment from the manufacturer requests that the unsafe 
condition statement in the AD be revised to remove P3B signal blockage 
and partial blockage as some of the causes of loss of engine thrust 
control. Blockage and

[[Page 53333]]

partial blockage of the P3B signal could result in a change to the 
engine acceleration schedule, and possibly a reduction in compressor 
stall margin, but a loss of thrust control would not occur. The FAA 
agrees. Reference to P3B signal blockage and partial blockage is 
removed from the unsafe condition statement in this AD.

Delete Certain Hardware From the Old Configuration Table

    Another comment from the manufacturer requests that three hardware 
items in the paragraph (k) Old Configuration Table be deleted to avoid 
confusion, because these items may be used in other locations on the 
engine. The FAA agrees. The hardware items which are a single tube 
clamp, double tube clamp, and bracket assembly, are deleted from the 
Old Configuration Table in this AD.

Delete Last Phrase of Unsafe Condition Description

    One commenter requests the deletion of the last phrase of the 
unsafe condition description, ``which if it occurs in a critical phase 
of flight, could result in loss of airplane control.'' The commenter 
did not provide a reason or justification for the request. The FAA 
partially agrees. As stated in the original AD, the FAA is especially 
concerned about the possibility of simultaneous loss of thrust control 
on both engines due to ice blockage of each engine's Ps3 pressure 
sensing system under certain atmospheric conditions. Corruption of Ps3 
signals could result in simultaneous loss of thrust control of both 
engines. The unsafe condition description is rewritten for 
clarification as follows: ``The actions specified in this AD are 
intended to prevent corruption of Ps3 signals, which could result in 
simultaneous loss of thrust control of both engines.''
    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.

Economic Analysis

    There are about 208 engines of the affected design in the worldwide 
fleet. The FAA estimates that 28 engines installed on aircraft of U.S. 
registry would be affected by this AD, that it would take about one 
work hour per engine to do the inspection and purging, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
total AD cost effect on U.S. operators for one inspection is estimated 
to be $1,680. The FAA also estimates that it would take about four work 
hours per engine to do the proposed P3B/Ps3 sense line replacement, and 
that the average labor rate is $60 per work hour. The manufacturer has 
stated that it may provide the redesigned hardware at no cost to 
operators. Based on this information, the total AD cost effect on U.S. 
operators for sense line replacement is estimated to be $6,720.

Regulatory Analysis

    This final 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 final 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 the DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 
will not have a significant economic effect, 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 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, 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 removing Amendment 39-11496 (65 FR 
692, January 6, 2000) and by adding a new airworthiness directive, 
Amendment 39-12473, to read as follows:

2001-21-03    General Electric Company: Amendment 39-12473. Docket 
No. 99-NE-62-AD. Supersedes AD 99-27-15, Amendment 39-11496.

    Applicability: General Electric Company (GE) Models GE90-76B, -
77B, -85B, and -90B turbofan engines. These engines are installed 
on, but not limited to Boeing 777 series airplanes.

    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 (m) 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 the requirements of this AD is 
required as indicated, unless already done.
    To prevent corruption of Ps3 signals, which could result in 
simultaneous loss of thrust control of both engines, do the 
following:
    Determination of Further Action
    (a) If the engine has been configured as specified in one of the 
following service bulletins (SB's), or has one of the following 
serial numbers (SN's), no further action is required.

(1) SB GE90 S/B 75-0031, Revision 1, dated August 29, 2000.
(2) SB GE90 S/B 75-0031, Revision 2, dated September 14, 2000.
(3) SB GE90 S/B 75-0031, Revision 3, dated March 30, 2001.
(4) Engine SN is 900-326, 900-328, 900-332, 900-333, 900-334, or 
higher.

Initial Inspection, Cleaning, Moisture Purging, and Blending

    (b) For engines that are not configured or listed by SN as 
specified in paragraph (a) of this AD, do the following:
    (1) Inspect, clean, moisture purge, and if necessary, blend any 
high metal, nicks, or burrs on fitting threads, on one engine 
installed on Boeing 777 series aircraft, within 10 cycles-in-service 
(CIS) after the effective date of this AD in accordance with the 
Accomplishment Instructions, Section 3 of GE Alert Service Bulletin 
(ASB) No. GE90 73-A0060, Revision 3, dated September 14, 2000.
    (2) Inspect, clean, moisture purge, and if necessary, blend any 
high metal, nicks, or burrs on fitting threads, on the other engine 
installed on the Boeing 777 series aircraft, within 20 CIS after the 
effective date of this AD in accordance with the Accomplishment 
Instructions, Section 3 of GE ASB No. GE90

[[Page 53334]]

73-A0060, Revision 3, dated September 14, 2000.

Credit for Previous Inspections, Cleaning, and Moisture Purging

    (c) For engines that have complied with the initial and 
repetitive inspections of AD 99-27-15, GE ASB No. GE90 73-A0060, 
Revision 1, dated March 1, 2000; GE ASB No. GE90 73-A0060, Revision 
2, dated May 12, 2000; GE ASB No. GE90 73-A0060, Revision 3, dated 
September 14, 2000; or with an FAA approved alternative method of 
compliance, perform repetitive inspections as specified in paragraph 
(d) of this AD.

Repetitive Inspections

    (d) Thereafter, inspect, clean, and moisture purge, and if 
necessary, blend any high metal, nicks, or burrs on fitting threads 
of each engine in accordance with the Accomplishment Instructions, 
Section 3, of GE ASB No. GE90 73-A0060, Revision 3, dated September 
14, 2000, within:
    (1) 30 CIS since-last-inspection, OR,
    (2) If applicable, 125 CIS since-last-inspection for one-engine-
only per airplane.

Replacement Engines

    (e) For replacement engines, perform the initial inspection, 
cleaning, and moisture purging, and if necessary, blend any high 
metal, nicks, or burrs on fitting threads as specified in paragraph 
(b) of this AD, except perform initial inspection before 
accumulating 30 CIS or 125 CIS, depending on the existing inspection 
interval for the engine that was replaced.

Idle Leak Check or Dual Signoff Procedure Check

    (f) After accomplishing the inspection and maintenance actions 
specified in paragraphs (b) through (e) of this AD, and before entry 
into service, do EITHER of the following:
    (1) Perform an idle leak check to confirm no P3B or Ps3 sense 
system faults in accordance with Accomplishment Instructions, 
Section 3, paragraph (15), of GE ASB No. GE90 73-A0060, Revision 3, 
dated September 14, 2000. OR,
    (2) Perform a dual signoff procedure check to confirm there are 
no loose fittings that could cause P3B and Ps3 sense system faults, 
in accordance with Accomplishment Instructions, Section 3, paragraph 
(15), of GE ASB No. GE90 73-A0060, Revision 3, dated September 14, 
2000. Idle leak checks that were performed using GE ASB No. GE90 73-
A0060, dated December 23, 1999, and idle leak checks or dual signoff 
procedure checks that were performed using GE ASB No. GE90 73-A0060, 
Revision 1, dated March 1, 2000, or GE ASB No. GE90 73-A0060, 
Revision 2, dated May 12, 2000, may be considered as alternative 
methods of compliance for this requirement.

Installation of Redesigned Hardware

    (g) At the next engine shop visit after the effective date of 
this AD, but not later than December 31, 2001, install the 
redesigned P3B and Ps3 tubes, hoses, clamps, and bracket assembly in 
accordance with Accomplishment Instructions, Section 3.A. through 
3.H. of GE ASB No. GE90 S/B 75-0031, Revision 3, dated March 30, 
2001.

Definition

    (h) For the purposes of this AD, an engine shop visit is defined 
as any time an engine has maintenance performed that involves 
separation of a major flange, such as removal of the low pressure 
turbine module, or high pressure compressor top case half.

Credit for Installation of Redesigned Hardware

    (i) Hardware installation that was performed using GE ASB No. 
GE90 S/B 75-0031, Revision 2, dated September 14, 2000; or GE ASB 
No. GE90 S/B 75-0031, Revision 1, dated August 29, 2000, may be 
considered as alternative methods of compliance for this 
requirement.

No Simultaneous Actions

    (j) Do not perform the actions required by this AD concurrently 
on both engines installed on Boeing 777 series aircraft.

Old Configuration Hardware

    (k) After the effective date of this AD, do not install any of 
the old configuration hardware listed in the following table.

             Old Configuration Hardware Not To Be Installed
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                         Part                               Part No.
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Ps3 Tube..............................................     350-151-505-0
                                                           350-184-806-0
                                                           350-114-005-0
Ps3 Hose..............................................     649-794-573-0
P3B Tube..............................................     350-151-604-0
                                                           350-184-904-0
                                                           350-114-105-0
P3B Hose..............................................     649-794-572-0
------------------------------------------------------------------------

Terminating Action

    (l) Installation of redesigned hardware as specified in 
paragraph (g) of this AD constitutes terminating action for 
requirements of paragraph (d) and paragraph (e) of this AD.

Alternative Methods of Compliance

    (m) 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 requests 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

    (n) 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.

Documents That Have Been Incorporated By Reference

    (o) The inspections and installation of redesigned hardware must 
be done in accordance with the following General Electric alert 
service bulletins (ASB's):

----------------------------------------------------------------------------------------------------------------
                 Document No.                     Pages     Revision                     Date
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ASB No. GE90 73-A0060.........................        1-8          3  September 14, 2000.
    Total pages: 8
ASB No. GE90 S/B 75-0031......................       1-36          3  March 30, 2001.
    Total pages: 36
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[[Page 53335]]

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 General Electric Company via 
Lockheed Martin Technology Services, 10525 Chester Road, Suite C, 
Cincinnati, OH 45215; telephone: (513) 672-8400, fax: (513) 672-
8422. 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.

Effective Date of This AD

    (p) This amendment becomes effective on November 26, 2001.

    Issued in Burlington, Massachusetts, on October 10, 2001.
Donald E. Plouffe,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 01-26324 Filed 10-19-01; 8:45 am]
BILLING CODE 4910-13-U