[Federal Register: January 6, 2004 (Volume 69, Number 3)]
[Rules and Regulations]
[Page 492-494]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr06ja04-4]
-----------------------------------------------------------------------
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.
-----------------------------------------------------------------------
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]
BILLING CODE 4910-13-P