[Federal Register Volume 67, Number 20 (Wednesday, January 30, 2002)]
[Rules and Regulations]
[Pages 4349-4351]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-1984]



[[Page 4349]]

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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-17-AD; Amendment 39-12622; AD 2002-01-27]
RIN 2120-AA64


Airworthiness Directives; General Electric Company GE90 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), that is applicable to General Electric Company (GE) GE90-76B, -
77B, -85B, -90B, and -92B model turbofan engines. That AD currently 
requires initial and repetitive eddy current inspections (ECI) for 
cracks in the high pressure compressor (HPC) stage 2-6 spool, and, if 
necessary, replacement with serviceable parts. That amendment was 
prompted by reports of cracks in the stage 3-4 and stage 4-5 interstage 
seal teeth and spacer arms. This amendment deletes reference to the 
GE90-92B engine model, deletes reference to HPC spool part number (P/N) 
350-005-769-0 and directs the removal from service of affected part 
number spools by either engine cycles or calendar date, whichever 
occurs first. This amendment is prompted by the introduction of a new 
design HPC stage 2-6 spool and four additional HPC stage 2-6 spool
P/N's that are terminating action for the repetitive inspection 
requirements for certain P/N spools. The actions specified by this AD 
are intended to prevent failure of the HPC stage 2-6 spool due to 
cracks, which could result in an uncontained engine failure and damage 
to the airplane.

DATES: Effective February 14, 2002. The incorporation by reference of 
certain publications listed in the rule is approved by the Director of 
the Federal Register as of February 14, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before April 1, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Regional 
Counsel, Attention: Rules Docket No. 98-ANE-17-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: ``[email protected]''. 
Comments sent via the Internet must contain the docket number in the 
subject line.
    The service information referenced in this AD may be obtained from 
General Electric Technical Services, Attention: Leader for 
distribution/microfilm, 10525 Chester Road, Cincinnati, OH 45215; 
telephone (513) 672-8400 Ext. 130, fax (513) 672-8422. 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; 
or at the Office of the Federal Register, 800 North Capitol Street, 
NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Ian Dargin, Aerospace Engineer, Engine 
Certification Office, FAA, Engine and Propeller Directorate, 12 New 
England Executive Park, Burlington, MA 01803-5299; telephone (781) 238-
7178, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: On July 6, 1998, the Federal Aviation 
Administration (FAA) issued airworthiness directive (AD) 98-15-03, 
Amendment 39-10654 (63 FR 37761, July 14, 1998), to require:
     Initial and repetitive eddy current inspection (ECI) for 
cracks in the high pressure compressor (HPC) stage 2-6 spool spacer 
arms, forward and aft of the stage 3-4 and stage 4-5 interstage seal 
teeth, and, if necessary, replacement with serviceable parts.
     A shop level ECI for cracks in the HPC stage 2-6 spool 
interstage seal teeth, and, if necessary, replacement with serviceable 
parts.
    That action was prompted by reports of cracked HPC stage 2-6 spools 
installed on General Electric Company (GE) GE90-76B, -77B, -85B, -90B, 
and -92B model turbofan engines. That condition, if not corrected, 
could result in failure of the HPC stage 2-6 spool due to cracks, which 
could result in an uncontained engine failure and damage to the 
airplane.
    Since that AD was issued, the FAA has determined that either of the 
inspection methods required by the current AD may be used to satisfy 
either inspection requirement if done in accordance with the applicable 
Service Bulletins. Furthermore, certain spools have been approved as 
terminating the need for continuing inspections. Lastly, the FAA has 
determined that the affected spools are required to be removed from 
service no later than a specified number of engine cycles or by June 
30, 2005, whichever occurs first.
    The manufacturer has confirmed the design integrity of two of the 
spools affected by the current AD, P/N 350-005-770-0 (except for SN 
LAO37677) and P/N 350-005-771-0. Based on additional test and analysis, 
these spools need no further inspection. In addition, the manufacturer 
has introduced a new design HPC stage 2-6 spool, P/N 350-005-780-0 and 
a repair procedure which creates two other spools part numbers, P/N 
350-005-775-0 and P/N 350-005-776-0. With spools having any of these 
five part numbers installed, this AD will no longer apply to the 
engine, terminating the requirement for additional inspections. Also, 
reference to the GE90-92B model is removed from the AD applicability 
because the manufacturer has informed the FAA that no engines of that 
model were produced and has requested the FAA remove this model 
designation from the GE90 Type Certificate. In addition, HPC spool P/N 
350-005-769-0 is deleted since the manufacturer has informed the FAA 
that this P/N spool has never been produced and will not be produced.

Manufacturer's Service Information

    The FAA has reviewed and approved the technical contents of GE 
Service Bulletin No. GE90 S/B 72-0352, Revision 4, dated July 31, 2000, 
that describes ECI procedures for cracks in the HPC stage 2-6 spool 
interstage seal teeth, and GE Alert Service Bulletin (ASB) No. GE90 72-
A0357, Revision 4, dated July 31, 2000, that describes procedures for 
ECI for cracks in the HPC stage 2-6 spool spacer arm, forward and aft 
of the stage 3-4 and stage 4-5 interstage seal teeth. This ASB also 
removes the inspection requirement for HPC spools P/N 350-005-770-0 
(except for S/N LAO37677) and P/N 350-005-771-0.

FAA's Determination of an Unsafe Condition and Required Actions

    Although none of these affected engine models are used on any 
airplanes that are registered in the United States, the possibility 
exists that the engine models could be used on airplanes that are 
registered in the United States in the future. Since an unsafe 
condition has been identified that is likely to exist or develop on 
other GE90 series turbofan engines of this same type design, this AD is 
being issued to prevent failure of the HPC stage 2-6 spool due to 
cracks, which could result in an uncontained engine failure and damage 
to the airplane. This AD requires:
     Initial and repetitive ECI for cracks in the HPC stage 2-6 
spool spacer arms, forward and aft of the stage 3-4 and

[[Page 4350]]

stage 4-5 interstage seal teeth, and, if necessary, replacement with a 
serviceable part.
     A shop level ECI for cracks in the HPC stage 2-6 spool 
interstage seal teeth, and, if necessary, replacement with serviceable 
parts.
     Removal of affected part number HPC stage 2-6 spools from 
service based on either engine cycles or calendar date, whichever 
occurs first.
    The actions must be done in accordance with the service bulletins 
described previously.

Immediate Adoption of This AD

    Since there are currently no domestic operators of these engine 
models, notice and opportunity for prior public comment are 
unnecessary. Therefore, a situation exists that allows the immediate 
adoption of this regulation.

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 98-ANE-17-AD.'' The postcard will be date stamped and 
returned to the commenter.

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 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 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 39-10654 (63 FR 
37761, July 14, 1998), and by adding a new airworthiness directive, 
Amendment 39-12622, to read as follows:

2002-01-27  General Electric Company (GE): Amendment 39-12622. 
Docket No. 98-ANE-17-AD. Supersedes AD 98-15-03, Amendment 39-10654.
    Applicability. This airworthiness directive (AD) is applicable 
to General Electric Company (GE) GE90-76B, -77B, --85B, and -90B 
turbofan engines, with high pressure compressor (HPC) stage 2-6 
spools, part numbers (P/N's) 350-005-761-0, 350-005-765-0, and 350-
005-770-0 (serial number (SN) LAO37677 only), installed. These 
engines are installed on, but not limited to, Boeing 777 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 (f) 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 failure of the HPC stage 2-6 spool due to cracks, 
which could result in an uncontained engine failure and damage to 
the airplane, do the following:
    (a) Perform initial and repetitive eddy current inspections 
(ECI) of the spacer arm, forward and aft of the stage 3-4 and 4-5 
seal teeth, for cracks in accordance with the Accomplishment 
Instructions of GE Alert Service Bulletin (ASB) No. GE90 72-A0357, 
Revision 4, dated July 31, 2000, as follows:
    (1) Perform the initial inspection before exceeding 500 cycles-
since-new (CSN).
    (2) Thereafter, inspect at intervals not to exceed 250 cycles-
in-service since last inspection.
    (3) Remove the spool from the engine if the ECI reveals a crack 
indication and replace with a serviceable spool before returning the 
engine to service.
    (4) Inspections required by this paragraph may be performed 
using an ECI for cracks in the HPC stage 2-6 spool interstage seal 
teeth in accordance with GE Service Bulletin (SB) No. GE90 S/B 72-
0352, Revision 4, dated July 31, 2000.
    (b) At each shop visit as defined in paragraph (e) of this AD, 
perform ECI for cracks in the HPC stage 2-6 spool interstage seal 
teeth in accordance with the Accomplishment Instructions of GE SB 
No. GE90 S/B 72-0352, Revision 4, dated July 31, 2000.
    (1) Replace spools with a crack indication with a serviceable 
spool before returning the engine to service.
    (2) If the HPC stage 2-6 spool is not exposed, the inspection 
required by this paragraph may be performed using an ECI for cracks 
in the HPC spacer arm, forward and aft of the stage 3-4 and 4-5 seal 
teeth, in accordance with the Accomplishment Instructions of GE ASB 
No. GE90 72-A0357, Revision 4, dated July 31, 2000.
    (c) Remove from service HPC stage 2-6 spools, P/N 350-005-761-0, 
350-005-765-0 and 350-005-770-0 (SN LAO37677 only), before 
accumulating 4,800 CSN for spools on the GE90-76B and -77B engine 
models and 4,600 CSN for spools on the GE90-85B and the -90B engine 
models, or by June 30, 2005, whichever occurs first.

[[Page 4351]]

Credit for Previous Inspections

    (d) Inspections performed before the effective date of this AD 
using the following SB's may be counted toward satisfying the 
initial and repetitive inspection requirements of paragraph (a) of 
this AD:
    (1) Inspections completed using GE ASB No. GE90 72-A0357, 
Revision 2, dated April 21, 1998; or Revision 3, dated October 27, 
1999.
    (2) Inspections completed during shop visits using GE SB No. 
GE90 S/B 72-0352, Revision 2, dated March 31, 1998; or Revision 3, 
dated July 12, 1999.

Definitions

    (e) For the purpose of this AD, an engine shop visit is defined 
as any time an engine has maintenance performed that involves 
separation of a major engine flange (such as removal of a low 
pressure turbine module or HPC ``top case''). However, the 
replacement of the stage 3 and 4 variable stator vane bushings and 
sealing flanges using GE SB No. GE90 S/B 72-0537, dated June 22, 
2001 is not considered a shop visit.

Alternative Methods of Compliance

    (f) 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

    (g) 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 done.

Documents That Have Been Incorporated By Reference

    (h) The inspection must be done in accordance with the following 
General Electric Company GE90 Service Bulletin (SB) and Alert 
Service Bulletin (ASB):

----------------------------------------------------------------------------------------------------------------
          Document No.                         Pages                 Revision                 Date
----------------------------------------------------------------------------------------------------------------
SB GE90 S/B 72-0352............  All.............................            4  July 31, 2000.
Total pages: 33
ASB GE90 72-A0357..............  All.............................            4  July 31, 2000.
Total pages: 30
----------------------------------------------------------------------------------------------------------------

These incorporations by reference were 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 Technical 
Services, Attention: Leader for distribution/microfilm, 10525 
Chester Road, Cincinnati, OH 45215; telephone (513) 672-8400 Ext. 
130, fax (513) 672-8422. Copies may be inspected, by appointment, 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

    (i) This amendment becomes effective on February 14, 2002.

    Issued in Burlington, Massachusetts, on January 18, 2002.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-1984 Filed 1-29-02; 8:45 am]
BILLING CODE 4910-13-U