Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan Engines

[Federal Register Volume 70, Number 237 (Monday, December 12, 2005)]
[Rules and Regulations]
[Pages 73361-73364]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-23897]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-48-AD; Amendment 39-14398; AD 2005-25-05]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) for

[[Page 73362]]

Pratt & Whitney (PW) JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, 
-15A, -17, -17A, -17R, and -17AR series turbofan engines. That AD 
currently requires revisions to the engine manufacturer's time limits 
section (TLS) to include enhanced inspection of selected critical life-
limited parts at each piece-part opportunity. This AD modifies the 
airworthiness limitations section of the manufacturer's manual and an 
air carrier's approved continuous airworthiness maintenance program to 
add an eddy current inspection. An FAA study of in-service events 
involving uncontained failures of critical rotating engine parts has 
indicated the need for mandatory inspections. The mandatory inspections 
are needed to identify those critical rotating parts with conditions, 
which if allowed to continue in service, could result in uncontained 
failures. We are issuing this AD to prevent critical life-limited 
rotating engine part failure, which could result in an uncontained 
engine failure and damage to the airplane.

DATES: This AD becomes effective June 12, 2006.

ADDRESSES: You may examine the AD docket 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 01803-5299; telephone (781) 
238-7189, fax (781) 238-7199.

SUPPLEMENTARY INFORMATION: The FAA proposed to amend 14 CFR Part 39 
with a proposed airworthiness directive (AD). The proposed AD applies 
to PW JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -
17A, -17R, and -17AR series turbofan engines. We published the proposed 
AD in the Federal Register on August 18, 2004 (69 FR 51203). That 
action proposed to require modifying the time limitations section of 
the manufacturer's manual and an air carrier's approved continuous 
airworthiness maintenance program to incorporate additional inspection 
requirements.

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.

Request To Change the Effective Date

    One commenter asks us to change the effective date to six to eight 
months. The commenter states the change will allow additional time to 
order, fabricate, and install automated inspection equipment. It will 
also allow more time to train employees on using the new equipment. We 
agree. We have extended the effective date 180 days to allow operators 
to set up their inspection process.

Concern the Costs To Comply Are Too Low

    One commenter suggests the NPRM fails to recognize the substantial 
up-front investment to get the equipment needed for the eddy current 
inspection (ECI). In addition, the commenter states we should increase 
the Costs of Compliance because the complex inspections will require 
several full-time, specially trained operators. We don't agree. The AD 
doesn't require air carriers to invest in tooling and equipment or hire 
more personnel to comply with the proposed AD. The AD requires adding 
the new ECI to the TLS of the engine manufacturer's manual, and to the 
air carriers' approved maintenance manuals. Operators can choose to buy 
equipment to perform the inspection, or they may send the disk to an 
approved service provider. We have not changed the AD.

Request To Change the ECI for Repaired Parts to Fluorescent Penetrant 
Inspection (FPI)

    The same commenter asks us to change the inspection method for 
parts previously repaired with bushings from an automated eddy current 
method to a fluorescent penetrant method. The commenter states that one 
cannot perform an automated ECI with the bushings installed. The 
commenter states that removing the bushings to perform the automated 
ECI would leave score marks because of the tight fit. We don't agree. 
The operators don't need to remove the bushings. The instructions for 
Section 72-33-31, Inspection -05, and Section 72-33-33, Inspection -03, 
state that holes with bushings installed are not subject to the ECI. 
Holes with bushings installed are subject to FPI and an additional 
visual inspection within the ECI instructions. We have not changed the 
AD.

Request To Perform an FPI If the Part Fails the ECI

    The same commenter suggests that service-run parts that fail the 
automated ECI should be subjected to an FPI. If the part fails the FPI, 
then the part is scrap. If the part passes the FPI, then it would be 
acceptable to perform the bushing repair. The commenter states that 
there is a possibility of false readings due to worn or oblong, but not 
cracked, holes that cause ``liftoff'' of the probe. We don't agree. The 
inspection instructions provide an opportunity to clean and reinspect 
the part. If the part fails again, the operator may return the disk to 
the manufacturer for a third opinion before determining if the part is 
acceptable or if it is scrap. The operator may propose other 
alternatives through the Alternative Method of Compliance process. We 
have not changed the AD.

Request for Clear Direction for Preparing the Surface of a Hole

    The same commenter asks us to provide clear direction for preparing 
the surface of a hole that is worn, oblong, or scored from removing a 
bushing. The commenter states the automated ECI equipment is extremely 
sensitive to surface finish. It might be necessary to machine the 
surface to provide an acceptable surface finish for the inspection. The 
commenter further states this is not desirable since the machining 
operation might mask or remove crack indications. We do not agree that 
we need to provide clearer instructions. The manufacturer has provided 
instructions to prepare the part for ECI. This AD does not allow any 
machining operations, although it does allow certain cleaning 
operations. Bushings are not subject to the ECI and must not be 
removed. We have not changed the AD.

Conclusion

    We have 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 have determined that these changes will neither increase the 
economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

    There are about 6,085 Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -
7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series turbofan 
engines of the affected design in the worldwide fleet. We estimate that 
this AD will affect 3,236 engines installed on airplanes of U.S. 
registry. We also estimate that it will take about 8 work

[[Page 73363]]

hours per engine to perform the proposed inspections, and that the 
average labor rate is $65 per work hour. Since this is an added 
inspection requirement, included as part of the normal maintenance 
cycle, no additional part costs are involved. Based on these figures, 
we estimate the total cost of the AD to U.S. operators to be 
$1,682,720.

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 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. 98-ANE-48-AD'' in your request.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, 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 Amendment 39-12867, (67 FR 
55108 August 28, 2002), and by adding a new airworthiness directive, 
Amendment 39-14398, to read as follows:

2005-25-05 Pratt & Whitney: Amendment 39-14398. Docket No. 98-ANE-
48-AD.

Effective Date

    (a) This AD becomes effective June 12, 2006.

Affected ADs

    (b) This AD supersedes AD 2002-17-02.

Applicability

    (c) This AD applies to Pratt & Whitney (PW) JT8D-1, -1A, -1B, -
7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR 
series turbofan engines. These engines are installed on, but not 
limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 
series airplanes.

Unsafe Condition

    (d) This AD results from the need to require enhanced inspection 
of selected critical life-limited parts of PW JT8D series turbofan 
engines. We are issuing this AD to prevent critical life-limited 
rotating engine part failure, which could result in an uncontained 
engine failure and damage to the airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified unless the 
actions have already been done.
    (f) Within the next 30 days after the effective date of this AD, 
(1) revise the Time Limits Section (TLS) of the manufacturer's 
Engine Manual, Part Number 481672, as appropriate for PW JT8D-1, -
1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and 
-17AR series turbofan engines, and
    (2) for air carriers, revise the approved mandatory inspections 
section of the continuous airworthiness maintenance program, by 
adding the following:
    ``Critical Life Limited Part Inspection
    A. Inspection Requirements:
    (1) This section has the definitions for individual engine piece 
parts and the inspection procedures which are necessary when these 
parts are removed from the engine.
    (2) It is necessary to do the inspection procedures of the piece 
parts in paragraph B when:
    (a) The part is removed from the engine and disassembled to the 
level specified in paragraph B and
    (b) The part has accumulated more than 100 cycles since the last 
piece part inspection, provided that the part was not damaged or 
related to the cause for its removal from the engine.
    (3) The inspections specified in this paragraph do not replace 
or make not necessary other recommended inspections for these parts 
or other parts.
    B. Parts Requiring Inspection:

    Note: Piece part is defined as any of the listed parts with all 
the blades removed.


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              Description                         Section                         Inspection Number
----------------------------------------------------------------------------------------------------------------
Hub (Disk), 1st Stage Compressor:
    Hub Detail--All P/Ns..............  72-33-31                    -02, -03, -04, -05
    Hub Assembly--All P/Ns............  72-33-31                    -02, -03, -04, -05
2nd Stage Compressor:
    Disk--All P/Ns....................  72-33-33                    -02, -03
    Disk Assembly--All P/Ns...........  72-33-33                    -02, -03
Disk, 13th Stage Compressor--All P/Ns.  72-36-47                    -02
HP Turbine Disk, First Stage w/         72-52-04                    -03
 integral Shaft--All P/Ns.
HP Turbine, First Stage, w/separable
 Shaft:
    Rotor Assembly--All P/Ns..........  72-52-02                    -04
    Disk--All P/Ns....................  72-52-02                    -03
Disk, 2nd Stage Turbine--All P/Ns.....  72-53-16                    -02
Disk, 3rd Stage Turbine--All P/Ns.....  72-53-17                    -02
Disk (Separable), 4th Stage Turbine--   72-53-15                    -02
 All P/Ns.
Disk (Integral Disk/Hub), 4th Stage     72-53-18                    -02''
 Turbine--All P/Ns.
----------------------------------------------------------------------------------------------------------------


[[Page 73364]]

Alternative Methods of Compliance

    (g) You must perform these mandatory inspections using the TLS 
and the applicable Engine Manual unless you receive approval to use 
an alternative method of compliance under paragraph (h) of this AD. 
Section 43.16 of the Federal Aviation Regulations (14 CFR 43.16) may 
not be used to approve alternative methods of compliance or 
adjustments to the times in which these inspections must be 
performed.
    (h) 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.

Maintaining Records of the Mandatory Inspections

    (i) You have met the requirements of this AD by using a TLS of 
the manufacturer's engine manual changed as specified in paragraph 
(f) of this AD, and, for air carriers operating under part 121 of 
the Federal Aviation Regulations (14 CFR part 121), by modifying 
your continuous airworthiness maintenance plan to reflect those 
changes. You must maintain records of the mandatory inspections that 
result from those changes to the TLS according to the regulations 
governing your operation. You do not need to record each piece-part 
inspection as compliance to this AD. For air carriers operating 
under part 121, you may use either the system established to comply 
with section 121.369 or use an alternative system that your 
principal maintenance inspector has accepted if that alternative 
system:
    (1) Includes a method for preserving and retrieving the records 
of the inspections resulting from this AD; and
    (2) Meets the requirements of section 121.369(c); and
    (3) Maintains the records either indefinitely or until the work 
is repeated.
    (j) These recordkeeping requirements apply only to the records 
used to document the mandatory inspections required as a result of 
revising the TLS as specified in paragraph (f) of this AD, and do 
not alter or amend the recordkeeping requirements for any other AD 
or regulatory requirement.

Related Information

    (k) None.

    Issued in Burlington, Massachusetts, on December 1, 2005.
Peter A. White,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 05-23897 Filed 12-9-05; 8:45 am]
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