[Federal Register Volume 68, Number 78 (Wednesday, April 23, 2003)]
[Proposed Rules]
[Pages 19962-19963]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 03-9984]


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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: [email protected]. 
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