[Federal Register: April 23, 2003 (Volume 68, Number 78)]
[Proposed Rules]
[Page 19962-19963]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr23ap03-10]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 2003-NE-01-AD]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT9D-7R4 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The Federal Aviation Administration (FAA) proposes to
supersede an existing airworthiness directive (AD) that is applicable
to Pratt & Whitney (PW) JT9D-7R4 series turbofan engines. That AD
currently requires modifications of the fan case assembly by installing
a thicker one-piece fan case shield, and modifications of the outer
front fan exit case assembly by installing ring segments. This proposal
would 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.
This proposal is prompted by two uncontained full fan blade fracture
events that resulted in penetration of the steel fan case and fan case
shield. The actions specified by the proposed AD are intended to
prevent uncontained fan blade failures, resulting in damage to the
airplane.
DATES: Comments must be received by June 23, 2003.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), New England Region, Office of the Regional
Counsel, Attention: Rules Docket No. 2003-NE-01-AD, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at
this location, by appointment, between 8 a.m. and 4:30 p.m., Monday
through Friday, except Federal holidays. Comments may also be sent via
the Internet using the following address: 9-ane-adcomment@faa.gov.
Comments sent via the Internet must contain the docket number in the
subject line.
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:
Comments Invited
Interested persons are invited to participate in the making of the
proposed 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 above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this action may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this action must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 2003-NE-01-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRM's
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, New England Region, Office of the Regional Counsel,
Attention: Rules Docket No. 2003-NE-01-AD, 12 New England Executive
Park, Burlington, MA 01803-5299.
Discussion
On August 3, 1989, the FAA issued airworthiness directive (AD) 87-
23-05R1, Amendment 39-6296 (55 FR 5594, February 16, 1990), to mandate
the incorporation of a thicker fan case shield for all JT9D-7R4 series
turbofan engine fan cases, before December 31, 1990. That action was
prompted by reports of failed fan blades that penetrated the fan case
shield after penetrating the fan case. Engines with fan cases made of
titanium do not require thicker fan case shields because the titanium
fan case and existing shield contains failed blades, and therefore are
not affected by this proposal.
Since that AD was issued, two reports of uncontained fan blade
failures that penetrated fan case shields were received, in November
1991 and June 2000. Subsequent ground inspections revealed that in each
event a fan blade fractured in the root of the blade airfoil, and
exited the engine through the fan case shield. These two uncontained
engine failures have shown that the thicker fan case shield mandated by
AD 87-23-05R1 is insufficient for containing failed fan blades on
engines with steel fan cases. This condition, if not corrected, could
result in uncontained fan blade failures, resulting in damage to the
airplane.
FAA's Determination of an Unsafe Condition and Proposed Actions
Since an unsafe condition has been identified that is likely to
exist or develop on other PW JT9D-7R4 series turbofan engines of the
same type design, the proposed AD would supersede AD 87-23-05R1 to
require on engines with steel fan cases, replacing existing fan case
shields with thicker four-piece fan case shields, and adding fan case
shield supports.
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 proposed AD. The FAA
also estimates that it would take approximately 16.6 work hours per
engine to perform the proposed actions, and that the average labor rate
is $60 per work hour. Required parts would cost approximately $3,675
per engine. Based on these figures, the total cost of the proposed AD
to U.S. operators is estimated to be $724,005.
Regulatory Analysis
This proposed 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
[[Page 19963]]
power and responsibilities among the various levels of government.
Accordingly, the FAA has not consulted with state authorities prior to
publication of this proposed rule.
For the reasons discussed above, I certify that this proposed
regulation (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) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action 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.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 removing Amendment 39-6296, (55 FR
5594, February 16, 1990), and by adding a new airworthiness directive:
Pratt & Whitney: Docket No. 2003-NE-01-AD.
Applicability: This airworthiness directive (AD) is applicable
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 (d) 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
engine overhaul where access to the fan case aft containment area is
available, 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 PW SB JT9D-7R4-72-
583, dated December 12, 2002.
(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, dated December 12, 2002.
(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,
dated December 12, 2002.
Alternative Methods of Compliance
(d) 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
(e) 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 airplane to a location where
the requirements of this AD can be done.
Issued in Burlington, Massachusetts, on April 17, 2003.
Francis A. Favara,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 03-9984 Filed 4-22-03; 8:45 am]
BILLING CODE 4910-13-P