[Federal Register Volume 69, Number 3 (Tuesday, January 6, 2004)]
[Rules and Regulations]
[Pages 492-494]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-45]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2003-NE-01-AD; Amendment 39-13422; AD 2004-01-08]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT9D-7R4 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to Pratt & Whitney (PW) JT9D-7R4 series turbofan engines. This 
amendment requires on JT9D-7R4 series turbofan engines with steel fan 
cases, replacement of the existing one-piece fan case shield with a 
thicker four-piece fan case shield and would add four fan case shield 
supports. This amendment results from two uncontained full fan blade 
fracture events that resulted in penetration of the steel fan case and 
fan case shield. We are issuing this AD to prevent uncontained fan 
blade failures, resulting in damage to the airplane.

DATES: Effective February 10, 2004.

ADDRESSES: The service information referenced in this AD may be 
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-7750; fax (860) 565-1605. This information may be 
examined, by appointment, at the Federal Aviation Administration (FAA), 
New England Region, Office of the Regional Counsel, 12 New England 
Executive Park, Burlington, MA.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an AD that applies to 
PW JT9D-7R4 series turbofan engines was published in the Federal 
Register on April 23, 2003 (68 FR 19962). That action proposed to 
require on JT9D-7R4 series turbofan engines with steel fan cases, 
replacement of the existing one-piece fan case shield with a thicker 
four-piece fan case shield and would add four fan case shield supports.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Update Material Cost

    Two commenters state that the material cost in the economic 
analysis published with the proposed AD is incorrect. They note that 
since the notice of proposed rulemaking (NPRM) was issued, a subsequent 
service bulletin (SB) revision was issued that quoted a higher price 
for the containment shield kit. The revised SB also included a 
reduction in the number of work hours to do the replacements.
    The FAA agrees. We have revised the economic analysis in this AD.

Request To Update Service Bulletin Revision and Date

    One commenter, the manufacturer, recommends that the four-piece fan 
cases, part numbers (P/Ns) 815132 and 821545, be installed using the 
information found in PW SB JT9D-7R4-72-583, Revision 1, and PW SB JT9D-
7R4-72-584, Revision 1, both dated September 10, 2003, instead of the 
original release of each SB, dated December 12, 2002. The manufacturer 
states that the SB revisions require changing the position of the 
shield attachment hardware and the assembly sequence to provide a 
better fit between the washer and the containment shield bolthole.
    The FAA agrees that these SB revisions enhance the installation 
process. Removal of the old containment shield, and proper installation 
of the new containment shield is the purpose of this AD. Since we are 
referencing the SBs for additional information only and are not 
incorporating those documents by reference, we have removed the date 
from the references in paragraphs (a), (b), and (c) in the AD. Removing 
the dates will allow the operator to refer to the latest revisions of 
the SBs.

Request To Comply at Next Heavy Maintenance vs. Repair

    One commenter believes the intent of this AD is to incorporate the 
new fan case shield assembly at the next heavy maintenance, which would 
involve separation of the ``B'' flange. During a less invasive visit 
(repair), the containment shields are not normally accessed and would 
cause an incremental cost increase.
    The FAA agrees. The purpose of this AD is to replace the 
containment shield the next time the fan case module is accessed, which 
would involve the separation of the ``B'' flange. The FAA has changed 
the compliance time to reference ``shop visit'' and added Paragraph (d) 
to provide a definition of ``shop visit'' that makes this intent clear. 
As a result, the remaining paragraphs are changed from (d) and (e) to 
(d), (e), (f), and (g).

Request for Clarification of Engine Overhaul vs. Shop Visit

    The same commenter expresses a concern about the ambiguous 
definition of engine overhaul and suggests that a simplified 
clarification might further reduce compliance times. The commenter also 
requests further clarification that the intent is a shop visit for 
heavy maintenance or overhaul.
    The FAA agrees. Since the AD intends to mandate the replacement of 
the containment shield during the next time the engine is serviced for 
an in-shop overhaul, and not during on-wing replacement, the compliance 
statement is revised by replacing ``engine overhaul where access to the 
fan case aft containment area is available'' with ``shop visit''. The 
definition of shop visit is added in a new paragraph (d) of the AD. As 
a result, the remaining paragraphs are changed from (d) and (e) to (d), 
(e), (f), and (g).

Request To Return to Pre-Compliance Build Standard To Utilize Spare 
Parts

    The same commenter asks that the AD include a provision to allow 
the removal of the four-piece fan case shield for those engines on 
which the improved containment has already been installed. The 
commenter seeks this provision to use up inventoried spare parts, but 
acknowledges that the final compliance date of December 31, 2012 must 
be met.

[[Page 493]]

    The FAA disagrees. Compliance with this AD is required at the next 
shop visit, which is defined as the separation of the B-flange except 
to replace fan case assemblies for rub strip repairs. Compliance is 
required at each shop visit. The FAA has included a compliance end-date 
of December 31, 2012, only to ensure that those engines, if there are 
any, that do not see a shop visit before that date have the improved 
containment shields installed. This compliance program establishes an 
acceptable level of safety based on the FAA's review of the entire 
fleet's exposure to the described unsafe condition, an analysis that 
does not contemplate the removal of the required improvements to the 
containment shield once installed.

Affect on Existing AD 87-23-05R1

    Although the FAA proposed that this AD would supersede AD 87-23-
05R1, after further review and careful consideration of all the 
comments received, the FAA has determined to publish this AD as a new 
AD and leave AD 87-23-05R1 in place. Superseding AD 87-23-05R1 would 
have had the effect of removing the requirements for installing P/N 
802096 on engines with titanium fan case assemblies and for modifying 
the fan case assemblies by installing ring segments, which are both 
critical to the safety of the containment shields. Removal of these 
requirements would not meet the intent of this AD.
    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Economic Analysis

    There are approximately 309 JT9D-7R4 series turbofan engines with 
steel fan cases, of the affected design in the worldwide fleet. The FAA 
estimates that 155 engines installed on PW JT9D-7R4 series turbofan 
engines of U.S. registry would be affected by this AD. The FAA also 
estimates that it would take approximately 1 work hour per engine to 
perform the actions, and that the average labor rate is $65 per work 
hour. Required parts would cost approximately $7,600 per engine. Based 
on these figures, the total cost of the AD to U.S. operators is 
estimated to be $1,188,075.

Regulatory Analysis

    This final rule does not have federalism implications, as defined 
in Executive Order 13132, because it would not have a substantial 
direct effect on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this final rule.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under the DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) will not have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. A final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
by contacting the Rules Docket at the location provided under the 
caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

Adoption of the Amendment

0
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

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. Section 39.13 is amended by adding a new airworthiness directive to 
read as follows:

2004-01-08 Pratt & Whitney: Amendment 39-13422. Docket No. 2003-NE-
01-AD.
    Applicability: This airworthiness directive (AD) applies to 
Pratt & Whitney (PW) JT9D-7R4D, -7R4D1, -7R4E, -7R4E1, -7R4E4, -
7R4G2, and -7R4H1 turbofan engines with steel fan cases. These 
engines are installed on, but not limited to, Airbus Industrie A300 
and A310, and Boeing 747 and 767 airplanes.

    Note 1: This AD applies to each engine identified in the 
preceding applicability provision, regardless of whether it has been 
modified, altered, or repaired in the area subject to the 
requirements of this AD. For engines that have been modified, 
altered, or repaired so that the performance of the requirements of 
this AD is affected, the owner/operator must request approval for an 
alternative method of compliance in accordance with paragraph (e) of 
this AD. The request should include an assessment of the effect of 
the modification, alteration, or repair on the unsafe condition 
addressed by this AD; and, if the unsafe condition has not been 
eliminated, the request should include specific proposed actions to 
address it.

    Compliance: Compliance with this AD is required at the next shop 
visit, but no later than December 31, 2012, unless already done.
    To prevent uncontained fan blade failures, resulting in damage 
to the airplane, do the following:
    (a) For PW JT9D-7R4D, -7R4D1, -7R4E, -7R4E1, -7R4E4, and -7R4H1 
turbofan engines with steel fan cases that have PW service bulletin 
(SB) 72-312 incorporated, replace fan case shield part number (P/N) 
802095 with the four-piece fan case shield and install four fan case 
shield supports. Information on replacing fan case shields and 
installing fan case shield supports can be found in PW SB JT9D-7R4-
72-583.
    (b) For PW JT9D-7R4G2 turbofan engines with steel fan cases that 
have PW SB 72-88 and PW SB 72-311 incorporated, replace fan case 
shield P/N 802094 with the four-piece fan case shield and install 
four fan case shield supports. Information on replacing fan case 
shields and installing fan case shield supports can be found in Part 
A of PW SB JT9D-7R4-72-584.
    (c) For PW JT9D-7R4G2 turbofan engines with steel fan cases that 
do not have PW SB 72-88 incorporated, but have PW SB 72-311 
incorporated, replace fan case shield P/N 802094 with the four-piece 
fan case shield and install four fan case shield supports. 
Information on replacing fan case shields and installing fan case 
shield supports can be found in Part B of PW SB JT9D-7R4-72-584.

Definitions

    (d) For the purpose of this AD, a shop visit is defined as 
separation of the B-flange during in-shop maintenance. Separation of 
the B-flange in order to replace fan case assemblies for rub strip 
repairs is not considered a shop visit.

Alternative Methods of Compliance

    (e) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Manager, Engine Certification Office (ECO). 
Operators must submit their request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

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

Special Flight Permits

    (f) Special flight permits may be issued in accordance with 
Sec. Sec.  21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the aircraft to a location where 
the requirements of this AD can be done.

[[Page 494]]

Effective Date

    (g) This amendment becomes effective on February 10, 2004.

    Issued in Burlington, Massachusetts, on December 29, 2003.
Robert E. Guyotte,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 04-45 Filed 1-5-04; 8:45 am]
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