Airworthiness Directives; Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, -17AR, -209, -217, -217A, -217C, and -219 Turbofan Engines

[Federal Register Volume 71, Number 168 (Wednesday, August 30, 2006)]
[Rules and Regulations]
[Pages 51459-51465]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-14238]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NE-30-AD; Amendment 39-14728; AD 2006-17-07]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D-1, -1A, -1B, -7, -
7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, -17AR, -209, -217, -
217A, -217C, and -219 Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) for Pratt & Whitney (PW) JT8D-209, -217, -217A, -217C, and -219 
turbofan engines. That AD currently requires initial and repetitive 
visual inspections for fretting and fluorescent magnetic particle 
inspections (FMPI) for cracking in the area of the tierod holes on 8th 
stage high pressure compressor (HPC) front hubs (from here on, referred 
to as HPC front hubs) that have operated at any time with PWA 110-21 
coating. This AD requires either replacing HPC front hubs and HPC disks 
that have operated at any time with PWA 110-21 coating and that 
operated in certain engine models, or, visually inspecting and FMPI for 
cracking of those parts and re-plating them if they pass inspection. 
This AD also requires adding JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -
11, -15, -15A, -17, -17A, -17R, and -17AR engines to the applicability. 
This AD results from an investigation by PW, which concluded that any 
HPC front hub or HPC disk coated with PWA 110-21 that ever operated on 
JT8D-15, -15A, -17, -17A, -17R, -17AR, -209, -217, -217A, -217C, and -
219 turbofan engines, could crack before reaching their published life 
limit. We are issuing this AD to prevent a rupture of an HPC front hub 
or an HPC disk that could result in an uncontained engine failure and 
damage to the airplane.

DATES: This AD becomes effective October 4, 2006. The Director of the 
Federal Register approved the incorporation by reference of certain 
publications listed in the regulations as of October 4, 2006.

ADDRESSES: You can get the service information identified in this AD 
from Pratt & Whitney, 400 Main St., East Hartford, CT 06108, telephone 
(860) 565-7700; fax (860) 565-1605.
    You may examine the AD docket at the FAA, New England Region, 
Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA. You may examine the service information, at the FAA, 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Keith Lardie, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; telephone (781) 238-
7189; fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR Part 39 
with a proposed AD. The proposed AD applies to PW JT8D-209, -217, -
217A, -217C, and -219 turbofan engines. We published the proposed AD in 
the Federal Register on December 30, 2005 (70 FR 77342). That action 
proposed to require either replacing HPC front hubs

[[Page 51460]]

and HPC disks that have operated at any time with PWA 110-21 coating 
and that operated in certain engine models, or, visually inspecting and 
FMPI for cracking of those parts and re-plating them if they pass 
inspection. That action also proposed to require adding JT8D-1, -1A, -
1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR 
engines to the applicability.

Examining the AD Docket

    You may examine the AD Docket (including any comments and service 
information), by appointment, between 8 a.m. and 4:30 p.m., Monday 
through Friday, except Federal holidays. See ADDRESSES for the 
location.

Comments

    We provided the public the opportunity to participate in the 
development of this AD. We have considered the comments received.

Question the Need To Inspect Every Stage of the Disks

    Two commenters question the need to inspect disks from additional 
HPC stages. The commenters ask how many instances of cracking, to what 
severity, in what types of coating, which operators, and how many 
cycles were accumulated.
    We do not agree. Our data shows that cracking was found in several 
HPC front hubs, as well as in other stages, if any mating surface 
between the HPC front hub and the 8-9 spacer is coated with PWA 110-21. 
Disks in other HPC stages have different initiation rates and, 
therefore, a lower risk of failing. But each stage has the same cause 
of cracking and carries a risk of failure that exceeds our risk 
criteria, if allowed to go until overhaul. We have no data that 
indicates the risk is operations dependent. We did not change the AD.

Request Clarification As To What Previous Actions Exempt an Engine From 
This AD

    Three commenters request clarification as to what previous actions 
exempt an engine from the requirements of this AD. They suggest that 
credit should be given to engines with HPC front hubs that have 
previously been inspected per PW Alert Service Bulletin (ASB) JT8D 
A6430 and associated AD 2002-23-14. They note that the proposed AD does 
not give this credit. They also suggest that the previous inspection 
under AD 2002-23-14 should be acceptable, even though the 7th stage HPC 
disks and 9th stage-through-12th stage HPC disks were not inspected. As 
currently written, the proposed AD would require operators to start the 
8th stage HPC front hub inspection program over because all of the 
proposed actions required may not have been performed previously. 
Industry would be required to remove previously inspected engines from 
service, reinspect the 8th stage HPC front hub, and inspect and 
``overhaul'' the entire HPC stack at tremendous expense and operational 
impact.
    We agree. All previous inspections before the effective date of 
this superseding AD are acceptable. The inspection schedule for all 
affected disks is based only on the HPC front hub inspection schedule. 
We will give credit for all engines that previously complied with AD 
2003-23-14. However, from the time of the effective date of this AD, 
all HPC disks and hubs stages 7-through-12 must be inspected for disk 
fretting when the front hub is inspected. We added the following 
statement to compliance paragraph (e) of this AD: ``Any engine with an 
HPC front hub that has been inspected using AD 2002-23-14, AD 2003-12-
07, or AD 2003-16-05, is considered in compliance with this AD.''

Inspection Schedule Seems Too Short an Interval

    Three commenters state that the inspection schedule for where the 
front hub is coated with Nickel-Cadmium and the 8-9 spacer is coated 
with PWA 110-21 seems too short an interval. Also, Rows (1) and (2) of 
Table 1 of the proposed AD seem inconsistent with the referenced PW 
ASBs. The commenters ask if this was the FAA's intent. For example, ASB 
JT8D A6430 is a less severe condition and allows the inspection to be 
postponed until next shop visit. Further, the ASBs force hub 
inspections (per the drawdown table) for hubs that operated with PWA 
110-21 coating. But for hubs that only operated plated with Nickel-
Cadmium (regardless of spacer coating type), the inspections are 
performed when the hub is accessible.
    We partially agree. The risk for front hubs plated with Nickel-
Cadmium is less severe than if the HPC front hub is coated with PWA 
110-21, so it is not accurate to maintain the same inspection limits. 
Our analysis does not agree with PW's that the risk is low enough to 
wait until next shop visit. We added Table 5 to maintain the inspection 
limits from AD 2002-23-14 in response to the comment.

Request To Clarify Inspection

    One commenter requests that we clarify that the inspection listed 
in PW ASB JT8D A6430, is valid for HPC front hubs coated with Nickel-
Cadmium. Paragraphs 1. through 1.A, and 2. through 2.C of that ASB only 
refer to HPC front hubs that are coated with PWA 110-21.
    We agree. We clarified the wording in this AD to indicate the 
correct inspection procedure.

Limit in Table 2 and Table 4 Should Be Changed

    Three commenters state that the limit in rows (iii) and (iv) of 
Table 2 and Table 4 of the proposed AD should be changed to match PW 
ASB JT8D A6430, Revision 2, dated December 23, 2004 and ASB JT8D A6468, 
dated December 23, 2004. It appears that the intent was to mirror the 
compliance as specified in the ASBs, but as-written, the compliance in 
rows (iii) and (iv) do not agree with the ASBs. Specifically, any disk 
with fewer than 5,000 cycles-in-service has conflicting requirements in 
rows (iii) and (iv).
    We agree and made that change in the AD.

Request To Change ``Hub Accessibility'' to ``Shop Visit''

    One commenter requests that we change the phrase ``hub 
accessibility'' to ``shop visit'' for determining the compliance 
schedule. The commenter points out that we defined ``shop visit'' in 
the proposed AD but did not use it in the compliance.
    We partially agree. Since ``shop visit'' is not being used in the 
AD, we omitted all definitions and clarifications of ``shop visit''. We 
also included a definition of ``accessible'' in the AD, to parallel the 
ASB.

Request To Remove the Word ``Terminating''

    One commenter requests that we remove the word ``terminating'' as 
described for the required inspections. The commenter states that their 
understanding is that the inspection is a onetime inspection and is not 
repetitive.
    We agree. Only those HPC front hubs that are accessible and 
inspected before 5,000 cycles-in-service require re-inspection. We 
removed the word ``terminating'' from the AD.

Request To Change Table Titles

    One commenter requests that we change the titles of Table 2 and 
Table 4 of the proposed AD from ``HPC Disk Inspection Schedule'' to 
``HPC Front Hub Inspection Schedule'', for clarification. We agree and 
made the changes in the AD.

[[Page 51461]]

Request To Add Additional Entries to Table 1

    One commenter requests that we add additional entries to Table 1 of 
the proposed AD to clarify AD applicability for Nickel-Cadmium coated 
HPC front hubs installed on JT8D-STD engines. We agree and have added a 
fourth column to Table 1 in the AD.

Request To Clarify the Intent To Inspect 8th Stage Hubs That Are in 
JT8D-1A, -1B, -7, -7A, -7B, -9, -9A, and -11 Engines

    One commenter requests that we clarify the intent to inspect 8th 
stage hubs that are in JT8D-1A, -1B, -7, -7A, -7B, -9, -9A, and -11 
engines. The commenter states that Table 1 of the proposed AD appears 
to be in conflict with paragraph (f)(1) of the proposed AD.
    We partially agree. Paragraph (f)(1) is not in conflict with Table 
1, but we changed the AD to clarify that paragraph (f)(1) is for 
engines as applicable in Table 1.

Suggestion To Use Flowchart

    One commenter suggests that we replace Table 1 of the proposed AD 
with a yes/no flowchart, which would be much easier to use since the 
decision logic is clearly conveyed. The commenter states that the FAA 
requires operators to have simple and concise manuals to ensure 
technicians understand tasks to be performed at the appropriate 
intervals. Table 2 ``HPC Disk Inspection Schedule'' in the proposed AD 
is complex, with numerous back and forth reading to determine the 
correct inspection interval.
    We partially agree. Our table format is adequate. Therefore, we did 
not change the table format in the AD. But we also interpret the 
commenter's suggestion as a request for additional clarity in the 
table's wording, similar to other comments we received. As noted in 
response to other comments, we made several changes to the AD for 
clarification as a result of earlier comments. No further clarification 
is needed.

Request To List Engine Manual Inspection and Associated Limits

    One commenter requests that we revise the proposed AD language that 
mandates use of inspection criteria from the service bulletins, to list 
the Engine Manual inspection and associated limits. The commenter 
states that the proposed AD language requires a strict adherence to the 
exact PW procedures. Operators have other Certificate Management 
Organization-approved maintenance programs that use alternate materials 
or processes. As written, operators would have to request Alternative 
Means of Compliance (AMOCs) to use their equivalent processes.
    We do not agree. As the standard practices of PW change, we will 
reevaluate them. Operators should submit an AMOC if they want to use 
other methods than those in this AD. We did not change the AD.

Request To Only Allow Use of Electroless Nickel

    One commenter requests that we change the proposed AD to only allow 
the use of Electroless Nickel. The proposed AD allows operators to 
restore the coating with Nickel-Cadmium. The PW Engine Manual allows 
the electrical contact area used on the spacers during Nickel-Cadmium 
restoration to be covered with PWA 595 (Aluminide paint) placing the 
same coating in the same critical areas of concern. ASB JT8D A6468 
leaves the electrical contact areas bare after the Nickel-Cadmium is 
applied. The bare electrical contact areas are open to oxidation. Using 
Electroless Nickel would eliminate the potential for corrosion in bare 
electrical contact areas resulting from the Nickel-Cadmium process.
    We do not agree that Electroless Nickel should be the only coating 
used. That would mean that Nickel-Cadmium coating must also be 
eliminated. Electroless Nickel may only be used on the spacers; not the 
disks. The data we have shows that corrosion on spacers is not an issue 
in the field. However, eliminating Electroless Nickel would leave 
several disks without protection against corrosion. We did not change 
the AD.

Request To Add Requirement That No PWA 110-21 Coated Units Be Re-
Installed

    One commenter requests that we standardize the coatings applied to 
all the steel disks and spacers, with a requirement that after the 
effective date of the AD, no PWA 110-21 coated units are to be 
installed in engines and or modules. PW ASB JT8D A6468 implies that the 
PWA 110-21 coating is no longer to be used. The detail in the 
accomplishment section of the ASB allows PWA 110-21 and Nickel-Cadmium 
to be applied to the disks and or hubs. Spacers can use one of three 
coatings, which are Nickel-Cadmium, PWA 110-21, or Electroless Nickel. 
Accomplishment of ASB JT8D A6468 is not proof that the units have 
eliminated PWA 110-21 coating from disks, hubs, and spacers. The 
current JT8D Engine Manual, P/N 481672, allows for any coating to be 
applied to the units under the proposed AD.
    We agree. 7th stage HPC disks, HPC front hubs, and stage 8-9 
spacers coated with PWA 110-21 are not serviceable. Removing the option 
to use PWA 110-21 coating from the engine manual prevents recoating and 
installing them. We changed the AD to prevent installation of those PWA 
110-21 coated parts.

Request To Continue This Inspection Program on All Units

    One commenter requests that we continue the inspection program even 
when operators install units that are not coated with PWA 110-21. The 
commenter states that the FAA is proposing to terminate the inspection 
program when the operators install units that have never used PWA 110-
21 or come in contact with PWA 110-21. This proposed AD could lead to 
noncompliance with the proposed AD, by the simple introduction of one 
unit that has been coated with PWA 110-21, as the FAA has not forced 
elimination of PWA 110-21 coating.
    We do not agree. This AD does not terminate the previous inspection 
program. The other disks are still subject to an inspection at the next 
shop visit per other ADs, mitigating the risk of cracking due to 
fretting. We did not change the AD.

Claim That Estimated Costs of Proposed AD Understated

    One commenter claims the estimated total cost to U.S. operators of 
the proposed AD is understated. The commenter estimates the labor hours 
to reassemble the areas accessed and make each engine serviceable, to 
be 172 hours. Further, the number of engines in service exceeds 1,573 
since all engines will be affected by the proposed AD, unless the 
inspection program for the hubs is synchronized with AD 2003-12-07.
    We do not agree. The commenter provided no data that indicates our 
estimate of affected U.S. engines is wrong, or that every engine will 
require 172 hours of work. Our analysis indicates this AD will result 
in only some engines being removed from service early. Further, we 
allow credit for previous inspections per AD 2002-23-14, as well as AD 
2003-12-07 and AD 2003-16-05. We did not change the AD.

Complete Visual Inspection Labor Hours Should Be Included

    One commenter states that the labor hours for the complete visual 
inspection

[[Page 51462]]

should be included in the cost of the proposed AD. The proposed AD 
implies that the inspection for corrosion as the result of fretting is 
a simple visual inspection. The inspection for corrosion requires a 
complete removal of the corrosion preventative coating and close visual 
examination with precision equipment or recognized standard to 
accurately determine the extent and depth of the corrosion in areas 
outside the spacer contact area
    We do not agree. The commenter provided no data to show that the AD 
will take longer than our estimate. We are only addressing costs 
related to the visual inspection for disk fretting. This AD is not 
about corrosion, and the inspection does not require specialized 
equipment. We did not change the AD.

Claim That Costs of Records Research Not Included

    Two commenters claim the proposed AD does not include the cost of 
records research. They suggest that operators will have to do extensive 
research of the engine and HPC module records. The only reliable 
records are the hub hours and cycles accumulated, indicating hub 
utilization in the engines. One of the commenters estimates that each 
engine search will require 8 labor hours.
    We do not agree. The cost to research records is not a valid cost 
for including in an estimate of cost of compliance for proposed ADs. We 
did not change the AD.

Additional Conditional Inspection Adds to the Cost

    One commenter states that the proposed AD includes a conditional 
requirement to inspect the remaining steel HPC disks and or hubs 
whenever the 8th stage hub is inspected. Unless it is synchronized with 
AD 2003-12-07, this additional conditional inspection adds to the cost 
of compliance to the proposed AD. Airworthiness Directive 2003-12-07 
currently requires inspection of the disks every four to eight calendar 
years, depending on the disk configuration or at two to four years, at 
shop exposure.
    We do not agree. Our costs estimate considers inspections that 
occur before a scheduled shop visit as a result of this AD. We do not 
consider the costs to comply with other ADs or requirements to be costs 
directly associated with this AD. We did not change the AD.

Claim That Including JT8D-1 Through -17AR Series Engines Is Unnecessary

    Two commenters claim that including the JT8D-1 through -17AR series 
engines into (the AD superseding) AD 2002-23-14 (JT8D-200 series) is 
unnecessary, based on the similarity of current requirements of AD 
2003-12-07 and AD 2003-16-05. AD 2003-12-07 has a more restrictive 
inspection interval than the inspections of the proposed AD. 
Discontinuing PWA 110-21 coating at the next disk spacer overhaul and 
only allowing Nickel-Cadmium recoating would be a more effective method 
to enhancing safety than the proposed AD. In addition, the HPC 7-12 
stage disk ``Corrosion ADs'' drive the inspection of HPC 7-through-12 
stage disks per the engine manual Inspection 01 and Inspection 02 for 
the applicable disks. Inspection 01 specifies the accomplishment of 
Inspection 03 (FMPI) and Inspection 04 (Fretting Inspection). During 
the accomplishment of AD 2003-16-05, the disks are stripped, visually 
and FMPI inspected, re-identified, and replated with Nickel-Cadmium. 
These procedures are identical to the procedures listed in this 
proposed AD.
    We do not agree. AD 2002-23-14 is only more restrictive for low- 
and medium-utilization carriers. For high-utilization carriers and 
older engines, this AD is more restrictive, which is why we proposed 
this AD. The inspections in AD 2003-12-07 and AD 2003-16-05, are 
similar, but not identical, nor are their compliance times the same as 
this AD. We did not change the AD.

Clarification of Definition

    In preparing the responses to the commenters requesting clarity, we 
found that our proposed definition of accessible in paragraph (o) could 
be clearer, and should coincide with how the term is used in Tables 2 
and 4. We did not change the meaning of the definition, but changed it 
from ``(o) For the purposes of this AD accessibility of the HPC front 
hub is removing the hub from the engine and deblading that hub'' to 
read ``(q) For the purpose of this AD, ``accessible'' is defined as 
when the HPC front hub is removed from the engine and the hub is 
debladed.'' It is now paragraph (q) because we added prohibition 
paragraphs (o) and (p) to this AD.

Conclusion

    We carefully reviewed the available data, including the comments 
received, and determined that air safety and the public interest 
require adopting the AD with the changes described previously. We 
determined that these changes will neither increase the economic burden 
on any operator nor increase the scope of the AD.

Costs of Compliance

    About 1,573 JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -
15A, -17, -17A, -17R, and -17AR turbofan engines, and 1,280 JT8D-200 
series turbofan engines, installed on airplanes of U.S. registry will 
be affected by this AD. We estimate it will take about 12 work-hours 
per engine to perform the proposed actions, and the average labor rate 
is $65 per work-hour. We also estimate 175 of those engines will be 
removed before reaching scheduled maintenance, and will require an 
additional 60 work-hours to disassemble and reassemble each engine. 
Based on these figures, we estimate the total cost of the AD to U.S. 
operators to be $2,907,840.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD will 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.
    For the reasons discussed above, I certify that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866;
    (2) Is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and
    (3) 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.
    We prepared a summary of the costs to comply with this AD and 
placed it in

[[Page 51463]]

the AD Docket. You may get a copy of this summary by sending a request 
to us at the address listed under ADDRESSES. Include ``AD Docket No. 
2001-NE-30-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the Federal Aviation Administration amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by removing 39-12958 (67 FR 70686, 
November 26, 2002) and by adding a new airworthiness directive, 
Amendment 39-14728, to read as follows:

2006-17-07 Pratt & Whitney: Amendment 39-14728. Docket No. 2001-NE-
30-AD.

Effective Date

    (a) This airworthiness directive (AD) becomes effective October 
4, 2006.

Affected ADs

    (b) This AD supersedes AD 2002-23-14, Amendment 39-12958.

Applicability

    (c) This AD applies to the following Pratt & Whitney (PW) JT8D-
1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, 
-17AR, -209, -217, -217A, -217C, and -219 turbofan engines, with 8th 
stage high pressure compressor (HPC) front hubs:

                                           Table 1.--AD Applicability
----------------------------------------------------------------------------------------------------------------
                                         And if the stage 8-9
 If the HPC front hub is coated with:   spacer is coated with:   And the HPC front hub:      Then this AD is:
----------------------------------------------------------------------------------------------------------------
(1) PWA 110-21 at any time...........  Any....................  Operated in a JT8D-15,   Applicable. See
                                                                 15A, -17, -17R, or -     paragraph (f) and
                                                                 17AR engine.             Table 2 of this AD.
(2) PWA 110-21 at any time...........  Any....................  Operated in a JT8D-209,  Applicable. See
                                                                 -217, -217A, -217C, or   paragraph (h) and
                                                                 -219 engine.             Table 4 of this AD.
(3) Nickel-Cadmium...................  PWA 110-21 at any time.  Operated in a JT8D-209,  Applicable. See
                                                                 -217, -217A, -217C, or   paragraph (i) and
                                                                 -219 engine.             Table 5 of this AD.
(4) Nickel-Cadmium...................  PWA 110-21 at any time.  Operated in a JT8D-1, -  Not applicable.
                                                                 1A, -1B, -7, -7A, -7B,
                                                                 -9, -9A, -11, -15, -
                                                                 15A, -17, -17R, or -
                                                                 17AR engine.
(5) PWA 110-21 at any time...........  Any....................  Operated in a JT8D-1, -  Not applicable.
                                                                 1A, -1B, -7, -7A, -7B,
                                                                 -9, -9A, or -11, but
                                                                 never operated in a
                                                                 JT8D-15, -15A, -17, -
                                                                 17A, -17R, -17AR, -
                                                                 209, -217, -217A, -
                                                                 217C, or -219 engine.
(6) Nickel-Cadmium...................  Any type but PWA 110-21  .......................  Not applicable.
----------------------------------------------------------------------------------------------------------------

    These engines are installed on, but not limited to, Boeing DC-9, 
MD-80 series, 727 series, and 737 series airplanes.

Unsafe Condition

    (d) This AD results from an investigation by PW which concluded 
that any HPC front hub or HPC disk coated with PWA 110-21 that ever 
operated on JT8D-15, -15A, -17, -17A, -17R, -17AR, -209, -217, -
217A, -217C, and -219 turbofan engines, could crack before reaching 
their published life limit. We are issuing this AD to prevent a 
rupture of an HPC front hub or an HPC disk that could result in an 
uncontained engine failure and damage to the airplane.

Compliance

    (e) You must accomplish the actions required by this AD within 
the compliance times specified, unless the actions have already been 
done. Any engine with an HPC front hub that has been inspected using 
AD 2002-23-14, AD 2003-12-07, or AD 2003-16-05, is considered in 
compliance with this AD.

JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -
17R, and -17AR Turbofan Engines--Inspect or Replace HPC Front Hubs, HPC 
Disks, and Stage 8-9 Spacers

    (f) For applicable JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, 
-15, -15A, -17, -17A, -17R, and -17AR turbofan engines specified in 
Table 1 of this AD, do the following:
    (1) Using the inspection schedule in Table 2 of this AD, strip 
the protective coating, visually inspect for fretting wear, 
fluorescent magnetic particle inspect (FMPI) for cracks, reidentify, 
replate HPC front hubs and stage 8-9 spacers, and replace if 
necessary.
    (2) Use paragraphs 1. through 3.B.(7)(b) under ``For Rear 
Compressor Front Hubs that Have Operated With PWA 110-21 coating AT 
ANY TIME During Their Service Life in JT8D-15, -15A, -17, -17A, -
17R, -17AR Engine Models.'' of PW Alert Service Bulletin (ASB) JT8D 
A6468, dated December 23, 2004.

               Table 2.--HPC Front Hub Inspection Schedule
------------------------------------------------------------------------
                                    Inspect before     Also inspect 7th
 HPC front hub cycles-Since-New   additional cycles-    stage HPC disks
 (CSN) on the effective date of    in-service (CIS)     and 9th stage-
             this AD               or CSN, whichever  through-12th stage
                                     occurs first      HPC disks using:
------------------------------------------------------------------------
(i) 19,000 or more..............  500 CIS or 20,000   Paragraph (f)(3)
                                   CSN.                of this AD.
(ii) 15,500 or more, but fewer    1,000 CIS or        Paragraph (f)(3)
 than 19,000.                      19,500 CSN.         of this AD.
(iii) 5,000 or more, but fewer    16,500 CSN........  Paragraph (f)(3)
 than 15,500.                                          of this AD.
(iv) Fewer than 5,000 that are    If the parts have   Paragraph (f)(3)
 accessible.                       been inspected      of this AD.
                                   and are
                                   acceptable, parts
                                   may be
                                   reinstalled.
                                   Inspect again
                                   using the
                                   criteria in (iii)
                                   of this Table.
------------------------------------------------------------------------


[[Page 51464]]

    (3) When the HPC front hub is inspected, visually inspect for 
fretting wear and FMPI for cracks on 7th stage HPC disks and 9th 
stage-through-12th stage HPC disks. Inspection information can be 
found in the applicable sections of JT8D Engine Manual Part Number 
(P/N) 481672, listed in the following Table 3:

 Table 3.--Seventh Stage HPC Disks and 9th Stage-Through-12th Stage HPC
                      Disks Inspection Information
------------------------------------------------------------------------
           Chapter/        Visual           Fretting
 Stage     section       inspection        inspection          FMPI
------------------------------------------------------------------------
7......     72-36-41  Inspection-01...  Inspection-04..  Inspection-03.
9......     72-36-43  Inspection-01...  Inspection-04..  Inspection-03.
10.....     72-36-44  Inspection-01...  Inspection-04..  Inspection-03.
11.....     72-36-45  Inspection-01...  Inspection-04..  Inspection-03.
12.....     72-36-46  Inspection-01...  Inspection-04..  Inspection-03.
------------------------------------------------------------------------

JT8D-15, -15A, -17, -17A, -17R, and -17AR Turbofan Engines--Cycle 
Adjustment for HPC Front Hubs That Entered Service With Nickel-Cadmium 
Plating and PWA 110-21 Coating

    (g) For JT8D-15, -15A, -17, -17A, -17R, and -17AR turbofan 
engines with front hubs that entered service with Nickel-Cadmium 
plating and PWA 110-21 coating, but have also operated during the 
life of the hub with PWA 110-21 coating:
    (1) You are allowed to make a cycle adjustment if the hub was 
never operated with a PWA 110-21-coated stage 8-9 spacer.
    (2) Use the information under ``Compliance'' of PW ASB JT8D 
A6468, dated December 23, 2004, to determine the adjustment.

JT8D-209, -217, -217A, -217C, and -219 Turbofan Engines--Inspect or 
Replace HPC Front Hubs and Stage 8-9 Spacers

    (h) For applicable JT8D-209, -217, -217A, -217C, and -219 
turbofan engines specified in Table 1, Row (1) of this AD, do the 
following:
    (1) Using the inspection schedule in Table 4 of this AD, strip 
the protective coating, visually inspect for fretting wear, FMPI for 
cracking, reidentify, replate HPC front hubs and the stage 8-9 
spacers, and replace if necessary.
    (2) Use paragraphs 1. through 1.A. and paragraphs 2. through 
2.C.(2)(g)2 of Accomplishment Instructions of PW ASB JT8D A6430, 
Revision 2, dated December 23, 2004.

Table 4.--HPC Front Hub Inspection Schedule--Hubs Coated With PWA 110-21
------------------------------------------------------------------------
                                                       Also inspect 7th
                                    Inspect before      stage HPC disks
    HPC front hub CSN on the       additional CIS or    and 9th stage-
    effective date of this AD       CSN, whichever    through-12th stage
                                     occurs first      HPC disks using:
------------------------------------------------------------------------
(i) 19,000 or more..............  500 CIS or 20,000   Paragraph (h)(3)
                                   CSN.                of this AD.
(ii) 15,500 or more, but fewer    1,000 CIS or        Paragraph (h)(3)
 than 19,000.                      19,500 CSN.         of this AD.
(iii) 5,000 or more, but fewer    16,500 CSN........  Paragraph (h)(3)
 than 15,500.                                          of this AD.
(iv) Fewer than 5,000 that are    If the parts have   Paragraph (h)(3)
 accessible.                       been inspected      of this AD.
                                   and are
                                   acceptable, parts
                                   may be
                                   reinstalled.
                                   Inspect again
                                   using the
                                   criteria in (iii)
                                   of this Table.
------------------------------------------------------------------------

    (i) For applicable JT8D-209, -217, -217A, -217C, and -219 
turbofan engines specified in Table 1, Row (2) of this AD, do the 
following:
    (1) Using the inspection schedule in Table 5 of this AD, strip 
the protective coating, visually inspect for fretting wear, FMPI for 
cracking, reidentify, replate HPC front hubs and the stage 8-9 
spacers, and replace if necessary.
    (2) Use paragraphs 1., 1.C, and 4. through 4.C.(2)(g)2 of 
Accomplishment Instructions of PW ASB JT8D A6430, Revision 2, dated 
December 23, 2004, for all applicable hubs with any type of coating.

  Table 5.--HPC Front Hub Inspection Schedule--Hubs Coated With Nickel-
                                 Cadmium
------------------------------------------------------------------------
                                                       Also inspect 7th
                                    Inspect before      stage HPC disks
    HPC front hub CSN on the       additional CIS or    and 9th stage-
    effective date of this AD       CSN, whichever    through-12th stage
                                     occurs first      HPC disks using:
------------------------------------------------------------------------
(i) 19,000 or more..............  500 CIS or 20,000   Paragraph (h)(3)
                                   CSN.                of this AD.
(ii) 17,000 or more, but fewer    1,000 CIS or        Paragraph (h)(3)
 than 19,000.                      19,500 CSN.         of this AD.
(iii) 9,000 or more, but fewer    18,000 CSN........  Paragraph (h)(3)
 than 17,000, that have not been                       of this AD.
 inspected.
(iv) 9,000 or more, but fewer     15,500 CSN........  Paragraph (h)(3)
 than 17,000, that were                                of this AD.
 inspected before accumulating
 9,000 CSN.
------------------------------------------------------------------------

    (j) When the HPC front hub is inspected, visually inspect for 
fretting wear and FMPI for cracks on 7th stage HPC disks and 9th 
stage-through-12th stage HPC disks. Inspection information can be 
found in the applicable sections of JT8D-200 Engine Manual P/N 
773128, listed in Table 3 of this AD.

JT8D-209, -217, -217A, -217C, and -219 Turbofan Engines--Cycle 
Adjustment for HPC Front Hubs That Entered Service With Nickel-Cadmium 
Plating and PWA 110-21 Coating

    (k) For JT8D-209, -217, -217A, -217C, and -219 turbofan engines 
with HPC front hubs

[[Page 51465]]

that entered service with Nickel-Cadmium plating, but have also 
operated during the life of the hub with PWA 110-21 coating:
    (1) You are allowed to make a cycle adjustment.
    (2) Use the information under ``CONDITION A'' of PW ASB JT8D 
A6430, Revision 2, dated December 23, 2004, to determine the 
adjustment.

Replacement of HPC Front Hubs and Stage 8-9 Spacers That Have Operated 
With PWA 110-21 Coating, As Optional Action--All Engines

    (l) For all applicable engines, as an optional action for the 
visual inspections in this AD, replace HPC front hubs and stage 8-9 
spacers that have operated with PWA 110-21 coating in the interface 
between the hub and the stage 8-9 spacer and HPC disks currently 
coated with PWA 110-21, as follows:
    (1) Install a Nickel-Cadmium plated HPC front hub that has never 
operated with PWA 110-21 coating in the interface between the HPC 
front hub and the stage 8-9 spacer.
    (2) Install a Nickel-Cadmium plated or Electroless Nickel-plated 
stage 8-9 spacer.
    (3) Install HPC disks that have never operated with PWA 110-21 
coating.

Prohibition Against Recoating the HPC Front Hub, Stage 7 HPC Disk, and 
Stage 8-9 Spacer With PWA 110-21--All Engines

    (m) Do not recoat the HPC front hub with PWA 110-21 (Repair-23 
of Chapter/Section 72-36-42 of JT8D-200 Engine Manual, P/N 773128, 
and Repair-27 and Repair-28 of Chapter/Section 72-36-42 of JT8D 
Engine Manual, P/N 481672).
    (n) Do not recoat the 7th stage disk with PWA 110-21 (Repair-15 
of Chapter/Section 72-36-41 of JT8D-200 Engine Manual, P/N 773128, 
and Repair-15 of Chapter/Section 72-36-41 of JT8D Engine Manual, P/N 
481672).
    (o) Do not recoat the stage 8-9 spacer with PWA 110-21 (Repair-
03, Task 72-36-12-30-003-002, of Chapter/Section 72-36-12 of JT8D-
200 Engine Manual, P/N 773128, and Repair-01, Task 72-36-12-30-001-
002, of Chapter/Section 72-36-12 of JT8D Engine Manual, P/N 481672).

Prohibition Against Reinstalling HPC Front Hubs and Stage 8-9 Spacers 
Coated With PWA 110-21

    (p) After the effective date of this AD, do not reinstall HPC 
front hubs and stage 8-9 spacers coated with PWA 110-21.

Definition

    (q) For the purpose of this AD, ``accessible'' is defined as 
when the HPC front hub is removed from the engine and the hub is 
debladed.

Alternative Methods of Compliance

    (r) The Manager, Engine Certification Office, has the authority 
to approve alternative methods of compliance for this AD if 
requested using the procedures found in 14 CFR 39.19.

Related Information

    (s) None.

Material Incorporated by Reference

    (t) You must use the service information specified in Table 6 of 
this AD to perform the actions required by this AD. The Director of 
the Federal Register approved the incorporation by reference of the 
documents listed in Table 6 of this AD in accordance with 5 U.S.C. 
552(a) and 1 CFR part 51. Contact Pratt & Whitney, 400 Main St., 
East Hartford, CT 06108, telephone (860) 565-7700; fax (860) 565-
1605 for a copy of this service information. You may review copies 
at the FAA, New England Region, Office of the Regional Counsel, 12 
New England Executive Park, Burlington, MA; or at the National 
Archives and Records Administration (NARA). For information on the 
availability of this material at NARA, call 202-741-6030, or go to: 
http://www.archives.gov/federal-register/cfr/ibr-locations.html.

                                      Table 6.--Incorporation by Reference
----------------------------------------------------------------------------------------------------------------
   Pratt & Whitney Alert Service
           Bulletin No.                      Page                Revision                      Date
----------------------------------------------------------------------------------------------------------------
JT8D A6430, Total Pages: 35.......  ALL..................  2...................  December 23, 2004.
JT8D A6468, Total Pages: 20.......  ALL..................  Original............  December 23, 2004.
----------------------------------------------------------------------------------------------------------------


    Issued in Burlington, Massachusetts, on August 21, 2006.
Francis A. Favara,
Manager, Engine and Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. E6-14238 Filed 8-29-06; 8:45 am]
BILLING CODE 4910-13-P

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