AD 2002-08-11

[Federal Register Volume 67, Number 78 (Tuesday, April 23, 2002)]
[Rules and Regulations]
[Pages 19663-19666]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 02-9844]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-47-AD; Amendment 39-12719; AD 2002-08-11]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes an existing airworthiness directive 
(AD), that is applicable to certain Pratt & Whitney JT9D series 
turbofan engines. That AD currently requires revisions to the 
Airworthiness Limitations Section (ALS) of the manufacturer's 
Instructions for Continued Airworthiness (ICA) to include required 
enhanced inspection of selected critical life-limited parts at each 
piece-part exposure. This action adds additional critical life-limited 
parts for enhanced inspection. This amendment is prompted by an FAA 
study of in-service events involving uncontained failures of critical 
rotating engine parts. The actions specified by this AD are intended to 
prevent critical life-limited rotating engine part failure, which could 
result in an uncontained engine failure and damage to the airplane.

DATES: Effective date May 28, 2002.

ADDRESSES: The information referenced in this AD may be examined, by 
appointment, 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: Tara Goodman, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (781) 
238-7130, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding AD 2000-01-13, 
Amendment 39-11511 (65 FR 2864, January 19, 2000), which is applicable 
to Pratt & Whitney (PW) JT9D series turbofan engines, was published in 
the Federal Register on November 20, 2001, (66 FR 58075). That action 
proposed to require revisions to the Airworthiness Limitations Section 
(ALS) of the

[[Page 19664]]

manufacturer's Instructions for Continued Airworthiness (ICA) to 
include required enhanced inspection of selected critical life-limited 
parts at each piece-part exposure.

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.

Add the -20 Model

    One commenter requests that the JT9D-20 engine model be added to 
the applicability paragraph.
    The FAA agrees. Although the JT9D-20 engine model was included in 
the Mandatory Inspections Table of the proposed rule, it was 
inadvertently omitted from the applicability paragraph of the proposed 
rule, and is now included in this final rule.

Modify Part Nomenclature

    One commenter requests that in the Mandatory Inspections Table, 
under the Part Nomenclature column, the words ``and Hubs'' be added to 
all four references to ``All LPT Stage 3-6 Disks'' to be consistent 
with manufacturer nomenclature.
    The FAA agrees. The four references in the Mandatory Inspections 
Table now read ``All LPT Stage 3-6 Disks and Hubs'' in this final rule.

Difference Between Existing AD and Proposal Paragraph (a)

    One commenter states that paragraph (a) of AD 2000-01-13 differs 
from the proposal paragraph (a). The AD paragraph (a) directs the 
revision to the Engine Time Limit Section (TLS) of the manufacturer's 
Engine Manuals by specifically listed Engine Manual part numbers, while 
the proposal states the necessity to revise the manufacturer's 
Airworthiness Limitation Section (ALS) of the Instructions for 
Continued Airworthiness (ICA). The commenter requests clarification.
    The FAA agrees with adding clarification. The wording in paragraph 
(a) of AD 2000-01-13 was changed in the proposal to be consistent with 
other engine models, however, the JT9D engine manuals are not 
consistent with the manuals of the other PW engine models. Also, the 
proposal included the engine manual part numbers in the table. 
Therefore, the FAA changes the wording of paragraph (a) in this final 
rule to read: ``Within the next 30 days after the effective date of 
this AD, revise the Engine-Time Limits-Airworthiness Limitations 
Section of the manufacturer's Engine Manual (EM) (JT9D manual part 
numbers provided in the Table of this AD) and for air carrier 
operations revise the approved continuous airworthiness maintenance 
program, by adding the following:''

Expand Cycles-In-Service Inspection Waiver

    One commenter states that there are circumstances where the part 
inspection would not normally be done. An example of this would be 
during the rotor balancing process; the inspection would be called out 
where the rotors may require removal and reinstallation of all blades 
at rearranged locations to meet balance requirements. The commenter 
proposes that paragraph (2)(ii) of the proposed change to the Engine 
Time Limits Section be reworded to allow 2,500 cycles-in-service since 
the last piece-part opportunity inspection for parts not damaged or 
related to the removal cause. This would ensure at least one mid-life 
inspection opportunity for the disk and hub, and would prevent 
unnecessary inspections due to rotor balance and other work 
requirements.
    The FAA disagrees. The commenter suggests that the 100 cycles-in-
service inspection waiver provided in the piece-part opportunity 
definition is too low and should be expanded to 2,500 cycles. The 100 
cycle waiver is intended to allow short-term relief from mandatory 
inspections for a part recently inspected in accordance with the engine 
manual requirements. The 100 cycle waiver is specifically aimed at 
disassembled parts removed from an engine following a test cell reject 
or some other event that caused the parts removal shortly after 
successful completion of mandatory inspections. Waiver of mandatory 
inspections in this instance also requires that the part was not 
damaged related to the cause for its removal from the engine. Mandatory 
inspections are required on fully disassembled parts regardless of 
time-since-new (TSN) or time-since-overhaul (TSO).
    The FAA is aware that cracks can be missed during part inspections 
and that each time a part is processed through an inspection line, the 
probability of detecting a crack is increased. Typical on-condition 
maintenance plans make it likely that a given part could be returned to 
service for thousands of cycles without the need for additional focused 
inspection. Recognizing two opposing aspects of part removal and 
inspection, which are the need for a brief exemption period following 
conduct of mandatory inspections and the benefits of increased 
frequency of inspection, the FAA established the 100 cycle threshold. 
No consideration for crack growth time was given in the choice of this 
number. It is strictly based on keeping the frequency of mandatory 
inspections as high as practicable and therefore increases the 
probability of crack detection while providing a brief window of 
exemption from mandatory inspection if certain conditions are met. 
Therefore, the 100 cycle limit will remain in paragraph (2)(ii) of the 
changes to the Engine Time Limits Section of the AD and no exemption 
will be allowed for infrequent circumstances that create a piece-part 
opportunity.
    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

    The FAA estimates that 837 engines installed on airplanes of US 
registry would be affected by this AD, that it would take approximately 
1 work hour per engine to do the proposed actions. The average labor 
rate is $60 per work hour. Based on these figures the total cost of the 
proposed AD on U.S. operators is estimated to be $954,180.

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.

[[Page 19665]]

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 removing Amendment 39-11511 (65 FR 
2864, January 19, 2000) and by adding a new airworthiness directive, 
Amendment 39-12719, to read as follows:

2002-08-11 Pratt & Whitney: Amendment 39-12719. Docket No. 98-ANE-
47-AD. Supersedes AD 2000-01-13, Amendment 39-11511.

    Applicability: This airworthiness directive (AD) is applicable 
to Pratt & Whitney (PW) JT9D-3A, -7, -7A, -7H, -7AH, -7F, -7J, -20, 
-20J, -59A, -70A, -7Q, -7Q3, -7R4D, -7R4D1, -7R4E, -7R4E1, -7R4E4, -
7R4G2, and -7R4H1 series turbofan engines, installed on but not 
limited to Boeing 747 and 767 series, McDonnell Douglas DC-10 
series, and Airbus Industrie A300 and A310 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 (c) 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 critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to 
the airplane, do the following:

Inspections

    (a) Within the next 30 days after the effective date of this AD, 
revise the Engine-Time Limits-Airworthiness Limitations Section of 
the manufacturer's Engine Manual (EM) (JT9D manual part numbers 
provided in the Table of this AD) and for air carrier operations 
revise the approved continuous airworthiness maintenance program, by 
adding the following:

Mandatory Inspections

    (1) Perform inspections of the following parts at each piece-
part opportunity in accordance with the instructions provided in the 
applicable manual provisions:

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                                                                                                            FPI per
            Engine model                     Engine manual part number             Part nomenclature         manual                Inspection
                                                                                                            section
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7/7A/7AH/7F, 7H/7J/20/20J...........  *646028 (or the equivalent customized    All Fan Hubs.............     72-31-04  02
                                       versions 770407 and 770408).
 
                                                                               All HPC Stage 5-15 Disks      72-35-00  03
                                                                                and Rear Compressor
                                                                                Drive Turbine Shafts.
                                                                               All HPT Stage 1-2 Disks       72-51-00  03
                                                                                and Hubs.
                                                                               All LPT Stage 3-6 Disks       72-52-00  03
                                                                                and Hubs.
--------------------------------------------------------------------------------------------------------------------------------------------------------
59A/70A.............................  754459.................................  All Fan Hubs.............     72-31-00  Heavy Maintenance Check.
                                                                               All HPC Stage 5-15 Disks      72-35-00  Heavy Maintenance Check.
                                                                                and Rear Compressor
                                                                                Drive Turbine Shafts.
                                                                               All HPT Stage 1-2 Disks       72-51-00  Heavy Maintenance Check-3.
                                                                                and Hubs.
                                                                               All LPT Stage 3-6 Disks       72-52-00  Heavy Maintenance Check-3.
                                                                                and Hubs.
--------------------------------------------------------------------------------------------------------------------------------------------------------
7Q/7Q3..............................  777210.................................  All Fan Hubs.............     72-31-00  03
                                                                               All HPC Stage 5-15 disks      72-35-00  03
                                                                                and Rear Compressor
                                                                                Drive Turbine Shafts.
                                                                               All HPT Stage 1-2 Disks       72-51-00  03
                                                                                and Hubs.
                                                                               All LPT Stage 3-6 Disks       72-52-00  03
                                                                                and Hubs.
--------------------------------------------------------------------------------------------------------------------------------------------------------
7R4.................................  785058, 785059, and 789328.............  All Fan Hubs.............     72-31-00  03
                                                                               All HPC Stage 5-15 Disks      72-35-00  03
                                                                                and Rear Compressor
                                                                                Drive Turbine Shafts.
                                                                               All HPT Stage 1-2 Disks       72-51-00  03
                                                                                and Hubs.
                                                                               All LPT Stage 3-6 Disks       72-52-00  03
                                                                                and Hubs.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* P/N 770407 and 770408 are customized versions of P/N 646028 engine manual.

    (2) For the purposes of these mandatory inspections, piece-part 
opportunity means:
    (i) The part is considered completely disassembled when done in 
accordance with the disassembly instructions in the manufacturer's 
engine manual; and
    (ii) The part has accumulated more than 100 cycles-in-service 
since the last piece-part opportunity inspection, provided that the 
part was not damaged or related to the cause for its removal from 
the engine.''
    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding contrary provisions in section 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
must be performed only in accordance with the Engine-Time Limits-
Airworthiness Limitations Section of the JT9D Engine Manual.

Alternative Method of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be

[[Page 19666]]

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

    (d) 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.

Continuous Airworthiness Maintenance Program

    (e) FAA-certificated air carriers that have an approved 
continuous airworthiness maintenance program in accordance with the 
record keeping requirement of Sec. 121.369(c) of the Federal 
Aviation Regulations (14 CFR 121.369(c)) of this chapter must 
maintain records of the mandatory inspections that result from 
revising the Time Limits section of the Instructions for Continuous 
Airworthiness (ICA) and the air carrier's continuous airworthiness 
program. Alternatively, certificated air carriers may establish an 
approved system of record retention that provides a method for 
preservation and retrieval of the maintenance records that include 
the inspections resulting from this AD, and include the policy and 
procedures for implementing this alternate method in the air 
carrier's maintenance manual required by Sec. 121.369(c) of the 
Federal Aviation Regulations (14 CFR 121.369(c)); however, the 
alternate system must be accepted by the appropriate PMI and require 
the maintenance records be maintained either indefinitely or until 
the work is repeated. Records of the piece-part inspections are not 
required under Sec. 121.380(a)(2)(vi) of the Federal Aviation 
Regulations (14 CFR 121.380(a)(2)(vi)). All other operators must 
maintain the records of mandatory inspections required by the 
applicable regulations governing their operations.

    Note 3: The requirements of this AD have been met when the 
engine manual changes are made and air carriers have modified their 
continuous airworthiness maintenance plans to reflect the 
requirements in the Engine Manuals.

Effective Date

    (f) This amendment becomes effective on May 28, 2002.

    Issued in Burlington, Massachusetts, on April 12, 2002.
Thomas A. Boudreau,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 02-9844 Filed 4-22-02; 8:45 am]
BILLING CODE 4910-13-U