[Federal Register Volume 62, Number 80 (Friday, April 25, 1997)]
[Rules and Regulations]
[Pages 20094-20098]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-10585]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-14; Amendment 39-9997; AD 97-09-01]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney PW2000 Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to Pratt & Whitney PW2000 series turbofan engines. This 
action requires initial and repetitive inspections for cracks in the 
forward face of the first stage high pressure turbine (HPT) disks at 
the base of the fir tree lug at the outer diameter (OD) snap fillet 
radius where the side plates mate with the disk, and rework to the 
first stage HPT disk. Additionally, this AD establishes a new, reduced 
cyclic life limit for certain disks. This amendment

[[Page 20095]]

is prompted by reports of two uncontained disk failures resulting from 
a fir tree lug fracturing, subsequently releasing two blades and a fir 
tree lug, which penetrated the engine HPT turbine case. The actions 
specified in this AD are intended to prevent fracture of the first 
stage HPT disk, resulting in a possible uncontained engine failure and 
damage to the aircraft.

DATES: Effective May 12, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of May 12, 1997.
    Comments for inclusion in the Rules Docket must be received on or 
before June 24, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 97-ANE-14, 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.
    The service information referenced in this AD may be obtained from 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; telephone (860) 
565-6600, fax (860) 565-4503. This information may be examined at the 
FAA, New England Region, Office of the Assistant Chief 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 Fisher, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7149, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA has received reports of two 
fractured first stage high pressure turbine (HPT) disks on Pratt & 
Whitney (PW) PW2000 series turbofan engines. The investigation revealed 
higher than expected stresses in an area known as the forward face of 
the first stage HPT disk at the base of the fir tree lug at the outer 
diameter (OD) snap fillet radius where the side plates mate with the 
disk. The FAA has determined that this snap fillet radius cannot be 
adequately inspected utilizing the prior method of fluorescent 
penetrant inspection, due to features on the disk that obstruct the 
view of the snap fillet radius. Pratt & Whitney has subsequently 
developed an eddy current inspection (ECI) probe which fits snugly into 
the snap fillet radius area for significantly improved crack 
detectability. In addition, the FAA has determined that the cracks form 
prior to the currently published disk cyclic life limit. This 
condition, if not corrected, could result in fracture of the first 
stage HPT disk, resulting in a possible uncontained engine failure and 
damage to the aircraft.
    The FAA has reviewed and approved the technical contents of PW 
Service Bulletin (SB) No. PW2000 72-588, Revision 1, dated March 31, 
1997, that describes procedures for inspections for cracks in the 
forward face of the first stage HPT disk at the base of the fir tree 
lug at the OD snap fillet radius where the side plates mate with the 
disk utilizing an eddy current inspection technique, and PW Alert 
Service Bulletin (ASB) No. PW2000 A72-592, dated March 18, 1997, that 
describes procedures for rework to the forward and aft faces of the 
first stage HPT disk OD snap fillet radii at the base of the fir tree 
lug.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other engines of the same type design, this AD is 
being issued to prevent a possible uncontained engine failure. The 
disks were manufactured using different types of materials and 
processing, and are identified by serial numbers. This AD requires 
initial and repetitive ECI for cracks in the forward face of the first 
stage HPT disk at the base of the fir tree lug at the OD snap fillet 
radius where the side plates mate with the disk. The AD also requires 
rework, consisting of removing material and increasing the radius of 
both the forward and rear face of the disk at the base of the fir tree 
lug where the side plates mate with the disk, and reidentification of 
reworked parts. In addition, this AD establishes a new, reduced cyclic 
life limit for disks that have been reworked prior to 5,000 cycles in 
service since new (CSN). Accomplishing the rework lowers stresses and 
assures that disks that are reworked after 5,000 CSN can reach the full 
published cyclic life limit. Currently there is no terminating action 
available to the inspection requirements of this AD. The actions are 
required to be accomplished in accordance with the SB and ASB described 
previously.
    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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-ANE-14.'' The postcard will be date stamped and 
returned to the commenter.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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,

[[Page 20096]]

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, 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 adding the following new 
airworthiness directive:

97-09-01  Pratt & Whitney: Amendment 39-9997. Docket 97-ANE-14.

    Applicability: Pratt & Whitney (PW) PW2000 series turbofan 
engines, installed on but not limited to Boeing 757 series, Ilyushin 
IL-96 series, and McDonnell Douglas Model C-17 (military) aircraft.

    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 (k) 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: Required as indicated, unless accomplished 
previously.
    To prevent fracture of the first stage high pressure turbine 
(HPT) disk, resulting in a possible uncontained engine failure and 
damage to the aircraft, accomplish the following:
    (a) Prior to further flight, for first stage HPT disks that are 
accessible in the shop, as defined in paragraph (j)(2) of this AD, 
on the effective date of this AD, perform eddy current inspections 
(ECI) of the first stage HPT disks for cracks in the forward face of 
the disk at the base of the fir tree lug at the outer diameter (OD) 
snap fillet radius where the side plates mate with the disk, in 
accordance with the Accomplishment Instructions of PW Service 
Bulletin (SB) No. PW2000 72-588, Revision 1, dated March 31, 1997, 
or Original, dated February 17, 1997.
    (b) For first stage HPT disks that are identified by serial 
number (S/N) in Table 1 of this AD, rework the forward and aft faces 
of the first stage HPT disk OD snap fillet radii at the base of the 
fir tree lug in accordance with PW Alert Service Bulletin (ASB) No. 
PW2000 A72-592, dated March 18, 1997, as follows:

                                 Table 1                                
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
                                   S/N                                  
                                                                        
N54398             N54399             N54400            N54401          
N54402             N54403             N54404            N54405          
N54406             N54407             N54408            N54409          
N54410             N54411             N54412            N54413          
N54414             N54415             N54416            N54417          
N54418             N54419             N55114            N55115          
N55116             N55117             P00624            P00625          
P00626             P00627             P00628            P00788          
P00812             P00813             P00814            P00815          
P00816             P00817             P00818            P00986          
P00987             P01018             P01457            P36249          
P36250             P36251             P36252            P36253          
P36254             P36255             P36256            P36258          
P36259             P36306             P36307            P36308          
P36309             P36310             P36311            P36312          
P36378             P36634             P36636            P36637          
P36638             P36639             P36805            P36806          
P37113             P37114             P37115            P37116          
P37117             P37118             P37324            P37325          
P37326             P37327             P37328            P37348          
P37349             P37351             P37352            P37353          
P37354             P90203             P90204            P90205          
P90206             P90207             P90208            P90209          
P90210             P90211             P90212            P90385          
P90386             P90387             P90388            P90389          
P90390             P91685             P91686            P91687          
P91688             P91854             P91855            P91856          
P91857             P91867             P91931            P91932          
P91933             P91934             P91935            R28552          
R28553             R28554             R28555            R28612          
R28613             R28614             R28615            R28617          
R28618             R28680             R28681            R28682          
R28683             R28684             R28685            R28686          
R28687             R28711             R28712            R28713          
R28714             R28715             R28716            R28718          
R28719             R28720             R28752            R28753          
R28755             R28756             R28757            R28758          
R28761             R28800             R28801            R28802          
R28803             R28804             R28805            R28806          
R28807             R28808             R28809            R28810          
R28811             R28812             R28813            R28847          
R28848             R28901             R28903            R28904          
R28905             R28906             R28907            R28908          
R28909             R28913             R28914            R28915          
R28933             R28934             R28935            R28936          
R28937             R28951             R28952            R28953          
R28954             R28955             R28956            S16633          
S16634             S16636             S16637            S16638          
S16639             S16641             S16642            S16643          
S16645             S16646             S16647            S16648          
S16649             S16650             S16651            S16652          
S16654             S16655             S16656            S16657          
S16658             S16659             S16660            S16661          
S16662             S16663             S16664            S16665          
S16666             S16667             S16668            S16669          
S16670             S16671             S16672            S16673          
S16674             S16675             S16676            S16677          
S16678             S16679             S16680            S16681          
S16682             S16683             S16684            S16685          
S16687             S16688             S16689            S16690          
S16691             S16692             S16693            S16694          
S16695             S16697             S16698            S16699          
S16700             S16701             S16702            S16703          
S16705             S16707             S16708            S16709          
S16710             S16712             S16713            S16715          
S16716             S16717             S16718            S16719          
S16720             S16721             S16723            S16724          
S16725             S16727             S16728            S16730          
S16731             S16732             S16733            S16735          
S16738             S16739             S16741            S16742          
S16743             S16744             S16745            S16746          
S16747             S16748             S16749            S16750          
S16751             S16752             S16753            S16756          
S16757             S16758             S16760            S16761          
S16762             S16763             S16765            S16766          
S16768             S16769             S16772            S16773          
S16774             S16775             S16776            S16777          
S16778             S16780             S16782            S16783          
S16784             S16786             S16787            S16789          
S16790             S16792             S16793            S16795          
S16798             S16800             S16802            S16803          
S16804             S16805             S16806            S16807          
S16808             S16810             S16811            S16814          
S16815             S16816             S16818            S16819          
S16821             S16822             S16824            S16825          
S16827             S16829             S16831            S16832          
------------------------------------------------------------------------

    (1) For disks that have accumulated 10,000 or more cycles since 
new (CSN) on the effective date of this AD, inspect and rework 
within 1,600 cycles in service (CIS) after the effective date of 
this AD.
    (2) For disks that have accumulated less than 10,000 CSN on the 
effective date of this AD, inspect and rework at the next shop 
visit, or 11,600 CSN, whichever occurs first.
    (c) For first stage HPT disks that are identified by S/N in 
Table 2 of this AD, rework the forward and aft faces of the first 
stage HPT disk OD snap fillet radii at the base of the fir tree lug 
in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, 
as follows:

                                 Table 2                                
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
                                   S/N                                  
                                                                        
M43410             M43411             M68250            M68251          
M68252             M68253             M68254            M68255          
M68256             M68344             M68345            M68346          
M68347             M68348             M68349            M68350          
M68536             M68537             M68538            M68539          
M68540             M68541             M68696            M68697          
M68698             M68699             M68700            M68701          
M68702             M68703             M68915            M68916          
M68917             M68918             M68919            M68997          
M68998             M69000             M69001            M85382          
M85383             M85384             M85385            M85386          
M85387             N09764             N09765            N09766          
N09767             N09768             N09769            N09770          
N09771             N09772             N09773            N09774          
N09775             N09776             N09777            N09778          
N11389             N11390             N11391            N11392          
N11393             N11394             N11395            N11396          
N11397             N11398             N11399            N11400          
N11401             N11402             N11403            N11404          
N11405             N11406             N11407            N12830          
N12831             N12832             N12833            N12834          
N12835             N12836             N12838            N12839          
N12840             N12841             N12842            N12843          

[[Page 20097]]

                                                                        
N12844             N12845             N12846            N12847          
N12848             N54390             N54391            N54392          
N54393             N54395             N54396            N54397          
------------------------------------------------------------------------

    (1) For disks that have accumulated 7,000 or more CSN on the 
effective date of this AD, inspect and rework within 800 CIS after 
the effective date of this AD.
    (2) For disks that have accumulated less than 7,000 CSN on the 
effective date of this AD, inspect and rework at the next shop 
visit, or 7,800 CSN, whichever occurs first.
    (d) For first stage HPT disks that are identified by S/N in 
Table 3 of this AD, rework the forward and aft faces of the first 
stage HPT disk OD snap fillet radii at the base of the fir tree lug 
in accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, 
as follows:

                                 Table 3                                
------------------------------------------------------------------------
                                                                        
------------------------------------------------------------------------
D301AA0002               D301AA0003               D301AA0004            
D301AA0005               D301AA0006               D301AA0008            
D301AA0009               D301AA0010               D301AA0011            
D301AA0013               D301AA0015               D301AA0018            
D301AA0019               D301AA0020               D301AA0021            
D301AA0022               D301AA0023               D301AA0024            
D301AA0025               D301AA0027               D301AA0028            
D301AA0029               D301AA0031               D301AA0032            
D301AA0033               D301AA0034               D301AA0035            
D301AA0038               D301AA0039               D301AA0040            
D301AA0041               D301AA0042               D301AA0044            
D301AA0045               D301AA0046               D301AA0047            
D301AA0048               D301AA0049               D301AA0050            
D301AA0051               D301AA0052               D301AA0053            
D301AA0054               D301AA0055               D301AA0056            
D301AA0057               D301AA0059               D301AA0061            
D301AA0062               D301AA0064               D301AA0065            
D301AA0066               D301AA0067               D301AA0068            
D301AA0069               D301AA0070               D301AA0071            
D301AA0072               D301AA0074               D301AA0075            
D301AA0077               D301AA0080               D301AA0081            
D301AA0082               D301AA0083               D301AA0084            
D301AA0085               D301AA0086               D301AA0087            
D301AA0088               D301AA0089               D301AA0090            
D301AA0091               D301AA0092               D301AA0093            
D301AA0094               D301AA0095               D301AA0096            
D301AA0098               D301AA0101               D301AA0102            
D301AA0103               D301AA0104               D301AA0105            
D301AA0106               D301AA0107               D301AA0108            
D301AA0110               D301AA0111               D301AA0114            
D301AA0118               D301AA0121               D301AA0123            
D301AA0124               D301AA0125               D301AA0127            
D301AA0129               D301AA0130               D301AA0131            
D301AA0132               D301AA0133               D301AA0135            
D301AA0137               D301AA0138               D301AA0140            
D301AA0141               D301AA0144               D301AA0145            
D301AA0146               D301AA0147               D301AA0148            
D301AA0149               D301AA0150               D301AA0151            
D301AA0152               D301AA0154               D301AA0156            
D301AA0157               D301AA0159               D301AA0161            
D301AA0163               D301AA0164               D301AA0165            
D301AA0166               D301AA0167               D301AA0171            
D301AA0174               D301AA0175               D301AA0177            
D301AA0179               D301AA0180               D301AA0182            
D301AA0187               D301AA0189               D301AA0198            
D301AA0201               D301AA0205               D301AA0358            
D301AA0359               D301AA0360               D301AA0361            
D301AA0362               D301AA0363               D301AA0364            
D301AA0367               D301AA0368               D301AA0369            
D301AA0370               D301AA0371               D301AA0372            
D301AA0375               D301AA0376               D301AA0377            
D301AA0379               D301AA0380               D301AA0381            
D301AA0382               D301AA0383               D301AA0384            
D301AA0386               D301AA0387               D301AA0388            
D301AA0390               D301AA0391               D301AA0392            
D301AA0393               D301AA0394               D301AA0395            
D301AA0396               D301AA0399               D301AA0401            
D301AA0402               D301AA0403               D301AA0404            
D301AA0406               D301AA0407               D301AA0408            
D301AA0412               D301AA0414               D301AA0415            
D301AA0416               D301AA0418               D301AA0419            
D301AA0420               D301AA0421               D301AA0422            
D301AA0423               D301AA0424               D301AA0425            
D301AA0426               D301AA0427               D301AA0428            
D301AA0431               D301AA0432               D301AA0434            
D301AA0435               D301AA0437               D301AA0438            
D301AA0439               D301AA0440               D301AA0443            
D301AA0444               D301AA0445               D301AA0446            
D301AA0447               D301AA0449               D301AA0450            
DKLBA78421               DKLBA78423               DKLBA78427            
DKLBA78429               DKLBA78431               DKLBA78432            
DKLBA78433               DKLBA78434               DKLBA78435            
DKLBA78436               DKLBA78437               DKLBA78438            
DKLBA78439               DKLBA78441               DKLBA78442            
DKLBA78443               DKLBA78444               DKLBA78446            
DKLBA78448               DKLBA78449               DKLBA78453            
DKLBA78454               DKLBA78455               DKLBA78456            
DKLBA78457               DKLBA78458               DKLBA78459            
DKLBA78465               DKLBA78467               DKLBA78468            
DKLBA78469               DKLBA78472               DKLBA78475            
DKLBA78482               DKLBA78483               DKLBA78484            
DKLBA78485               DKLBA78486               DKLBA78487            
DKLBA78488               DKLBA78489               DKLBA78490            
DKLBA78491               DKLBA78492               DKLBA78493            
DKLBA78496               DKLBA78497               DKLBA78498            
DKLBA78500               DKLBA78502               DKLBA78503            
DKLBA78504               DKLBA78505               DKLBA78506            
DKLBA78507               DKLBA78508               DKLBA78509            
DKLBA78510               DKLBA78512               DKLBA78514            
DKLBA78515               DKLBA78517               DKLBA78518            
DKLBA78519               DKLBA78520               DKLBA78521            
DKLBA78522               DKLBA78524               DKLBA78525            
DKLBA78526               DKLBA78527               DKLBA78528            
DKLBA78529               DKLBA78530               DKLBA78531            
DKLBA78533               DKLBA78534               DKLBA78536            
DKLBA78537               DKLBA78538               DKLBA78540            
DKLBA78541               DKLBA78542               DKLBA78543            
DKLBA78544               DKLBA78545               DKLBA78550            
DKLBA78551               DKLBA78552               DKLBA78553            
DKLBA78554               DKLBA78557               DKLBA78558            
DKLBA78559               DKLBA78560               DKLBA78561            
DKLBA78562               DKLBA78564               DKLBA78568            
DKLBA78569               DKLBA78575               DKLBA78577            
DKLBA78578               DKLBA78579               DKLBA78580            
DKLBA78581               DKLBA78582               DKLBA78584            
DKLBA78585               DKLBA78587               DKLBA78589            
DKLBA78590               DKLBA78593               DKLBA78594            
DKLBA78596               DKLBA78598               DKLBA78600            
DKLBA78601               DKLBA78603               DKLBA78604            
DKLBA78605               DKLBA78606               DKLBA78607            
DKLBA78609               DKLBA78610               DKLBA78611            
DKLBA78613               DKLBA78614               DKLBA78615            
DKLBA78616               DKLBA78617               DKLBA78618            
DKLBA78620               DKLBA78622               DKLBA78625            
DKLBA78627               DKLBA78628               DKLBA78632            
DKLBA78633               DKLBA78635               DKLBA78636            
DKLBA78638               DKLBA78639               DKLBA78640            
DKLBA78642               DKLBA78644               DKLBA78645            
DKLBA78646               DKLBA78648               DKLBA78649            
DKLBA78650               DKLBA78651               DKLBA78652            
DKLBA78653               DKLBA78654               DKLBA78655            
DKLBA78656               DKLBA78657               DKLBA78658            
DKLBA78660               DKLBA78661               DKLBAH8318            
DKLBAH8319               DKLBAH8320               DKLBAH8321            
DKLBAH8322               DKLBAH8323               DKLBAH8324            
DKLBAH8325               DKLBAH8327               DKLBAH8328            
DKLBAH8329               DKLBAH8330               DKLBAH8331            
DKLBAH8332               DKLBAH8333               DKLBAH8336            
DKLBAH8337               DKLBAH8339               DKLBAH8340            
DKLBAH8343               DKLBAH8344               DKLBAH8346            
DKLBAH8347               DKLBAH8348               DKLBAH8349            
DKLBAH8350               DKLBAH8351               DKLBAH8352            
DKLBAH8353               DKLBAH8354               DKLBAH8355            
DKLBAH8356               DKLBAH8357               DKLBAH8360            
DKLBAH8361               DKLBAH8362               DKLBAH8364            
DKLBAH8365               DKLBAM0972               DKLBAM0973            
L82270                   L82271                   L82272                
L82356                   L82649                   L82650                
L83308                   L83309                   L83310                
L83311                   L83312                   M15709                
M15710                   M15718                   M42710                
M42711                   M42768                   M42769                
M42770                   M42771                   M43103                
M43104                   M43105                   M43396                
M43397                   M43398                   M43399                
M43400                   M43401                   M43409                
------------------------------------------------------------------------

    (1) For disks that have accumulated 7,000 or more CSN on the 
effective date of this AD, inspect and rework within 1,100 CIS after 
the effective date of this AD.
    (2) For disks that have accumulated less than 7,000 CSN on the 
effective date of this AD, inspect and rework at the next shop 
visit, or 8,100 CSN, whichever occurs first.
    (e) For disks that have previously been inspected in accordance 
with PW SB No. PW2000 72-588, Revision 1, dated March 31, 1997, or 
Original, dated February 17, 1997, but not reworked in accordance 
with PW ASB No. PW2000 A72-592, dated March 18, 1997, rework in 
accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, at 
the next shop visit when the part is accessible, as defined in 
paragraph (j)(2) of this AD, or 4,000 CIS since inspection in 
accordance with PW SB No. PW2000 72-588, Revision 1, dated March 31, 
1997, or Original, dated February 17, 1997, whichever occurs first.
    (f) Prior to further flight, remove and replace disks with 
cracks. Disks with cracks cannot be reworked.
    (g) If reworked, reidentify the disk in accordance with the 
Accomplishment Instructions of PW ASB No. PW2000 A72-592, dated 
March 18, 1997.
    (h) For all first stage HPT disks that have been reworked in 
accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997, 
thereafter inspect in accordance with PW Temporary Revision 72-937, 
dated April 11, 1997, to Engine Manual, P/N 1A6231, Section 72-52-
02, Inspection Check 04, at each subsequent shop visit when the disk 
is accessible, as defined in paragraph (j)(2) of this AD, not to 
exceed 6,000 CIS since last inspection.
    (i) The following cyclic life limits apply to disks that are 
reworked in accordance with the Accomplishment Instructions of PW 
Alert Service Bulletin (ASB) No. PW2000 A72-592, dated March 18, 
1997:
    (1) Disks that have accumulated less than 5,000 CSN upon rework 
may accumulate an additional 10,000 CIS following rework, and then 
must be retired from service.
    (2) Disks that have accumulated 5,000 CSN or more upon rework 
may remain in service to the full 15,000 CSN published life limit, 
and then must be retired from service.
    (3) Except as provided in paragraph (k) of this AD, no 
alternative life limits may be approved for disks reworked in 
accordance with PW ASB No. PW2000 A72-592, dated March 18, 1997.
    (j) For the purpose of this AD, the following definitions apply:
    (1) A shop visit is defined as an engine removal where engine 
maintenance, prior to reinstalling the engine, entails separation of 
pairs of mating major engine flanges or the removal of a disk, hub, 
or spool.
    (2) An accessible disk is defined as a disk that is in the shop, 
has been removed from the HPT module, separated from the rotor, and 
debladed.

[[Page 20098]]

    (k) 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. The 
request should be forwarded through an appropriate FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Engine Certification Office.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Engine Certification Office.

    (l) 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 inspection and rework requirements of this AD can be 
accomplished.
    (m) The actions required by this AD shall be done in accordance 
with the following PW service documents:

----------------------------------------------------------------------------------------------------------------
            Document No.                Pages                  Revision                          Date           
----------------------------------------------------------------------------------------------------------------
SB No. PW2000                                                                                                   
    72-588.........................            1  1................................  Mar. 31, 1997.             
                                               2  Original.........................  Feb. 17, 1997.             
                                            3-12  1................................  Mar. 31, 1997.             
NDIP-899...........................         1-23  A................................  Mar. 25, 1997.             
    Total Pages: 35                                                                                             
SB No. PW2000                                                                                                   
    72-588.........................         1-12  Original.........................  Feb. 17, 1997.             
NDIP-899...........................         1-23  Original.........................  Feb. 16, 1997.             
SB No. PW2000                                                                                                   
    72-588.........................           38  Original.........................  Feb. 17, 1997.             
    Total Pages: 36                                                                                             
ASB No. PW2000                                                                                                  
    A72-592........................         1-16  Original.........................  Mar. 18, 1997.             
    Total Pages: 16                                                                                             
----------------------------------------------------------------------------------------------------------------

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 Pratt & Whitney, 400 Main St., East 
Hartford, CT 06108; telephone (860) 565-6600, fax (860) 565-4503. 
Copies may be inspected at the FAA, New England Region, Office of 
the Assistant Chief 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.
    (n) This amendment becomes effective on May 12, 1997.

    Issued in Burlington, Massachusetts, on April 17, 1997.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 97-10585 Filed 4-24-97; 8:45 am]
BILLING CODE 4910-13-U