[Federal Register Volume 64, Number 101 (Wednesday, May 26, 1999)]
[Rules and Regulations]
[Pages 28357-28358]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-13322]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-ANE-54 AD; Amendment 39-11180; AD 99-11-09]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

-----------------------------------------------------------------------

SUMMARY: This document supersedes an existing airworthiness directive 
(AD), applicable to Pratt & Whitney (PW) JT9D series turbofan engines, 
that currently requires initial and repetitive in-shop or on-wing 
inspections of the diffuser case rear rail for cracking, and removal, 
if necessary, of the diffuser case. This AD will reduce the allowable 
crack length, reduce the inspection intervals, and introduce an 
improved inspection method. This AD is prompted by continued reports of 
diffuser case ruptures, and improved understanding of crack propagation 
rates. The actions specified by this AD are intended to prevent 
diffuser case rupture, uncontained engine failure, and damage to the 
aircraft.

DATES: Effective July 26, 1999. The incorporation by reference of 
certain publications listed in the regulations is approved by the 
Director of the Federal Register as of July 26, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from. Pratt & Whitney, 400 Main St., East Hartford, CT 06108; 
telephone (860) 565-6600, fax (860) 565-4503. This information may be 
examined at the Federal Aviation Administration (FAA), New England 
Region, Office of the Regional Counsel, 12 New England Executive Park, 
Burlington, MA 01803-5299; or at the Office of the Federal Register, 
800 North Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Peter White, Aerospace Engineer, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803-5299; telephone (617) 
238-7128, fax (617) 238-7199.

SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) by superseding airworthiness 
directive (AD) 94-26-06, Amendment 39-9102 (59 FR 67176, December 29, 
1996, applicable to certain Pratt & Whitney (PW) (PW) JT9D-59A, -70A, -
7Q, and -7Q3 series turbofan engines, was published in the Federal 
Register on January 11, 1999 (64 FR 1552). That action proposed to 
require initial and repetitive in-shop or on-wing inspections of the 
diffuser case rear rail for cracking, and removal, if necessary, of the 
diffuser case.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    Two commenters state that they are not affected by this AD.
    A third commenter states that minimal impact is expected from the 
AD as premature removal of the affected parts is planned.
    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 as proposed.
    There are approximately 566 engines of the affected design in the 
worldwide fleet. The FAA estimates that 157 engines installed on 
aircraft of U.S. registry will be affected by this AD, that it would 
take approximately 29 work hours per engine to accomplish the proposed 
actions, and that the average labor rate is $60 per work hour. Based on 
these figures, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $273,180.
    The regulations adopted herein will not have substantial direct 
effects 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. Therefore, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    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 
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, Incorporation by 
reference, Safety.

Adoption of the Amendment

    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:

[[Page 28358]]

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 adding the following new 
airworthiness directive:

99-11-09  Pratt & Whitney: Amendment 39-11180. Docket No. 94-ANE-54. 
Supersedes AD 94-26-06, Amendment 39-9102.

    Applicability: Pratt & Whitney (PW) JT9D-59A, -70A, -7Q, and -7Q3 
series turbofan engines, installed on but not limited to Airbus A300 
series, Boeing 747 series, and McDonnell Douglas DC-10 series aircraft.

    Note 1: This airworthiness directive (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 (b) 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: Required as indicated, unless accomplished 
previously.
    To prevent diffuser case rupture, an uncontained engine failure, 
and damage to the aircraft, accomplish the following:
    (a) Perform initial and repetitive fluorescent penetrant 
inspections (FPI) or eddy current inspections (ECI) of diffuser case 
rear rails for cracks in accordance with the Accomplishment 
Instructions of PW JT9D (SB) No. 5749, Revision 8, dated October 30, 
1998, as follows:
    (1) For engines on-wing that have not had the diffuser case rear 
rail FPI or ECI inspected using the procedures referenced in PW JT9D 
SB No. 5749, Revision 4, dated May 10, 1993; Revision 5, dated 
September 29, 1995; Revision 6, dated May 8, 1998; Revision 7, dated 
August 19, 1998; or Revision 8, dated October 30, 1998; Section 2, 
Part 1 A (1)-(3), accomplish the following:
    (i) Perform an initial on-wing inspection within 25 cycles of 
the effective date of this AD in accordance with Section 2, Part 2 
of PW JT9D SB No. 5749, Revision 8, dated October 30, 1998.
    (ii) Thereafter, except as provided in paragraph (a)(4) of this 
AD, perform on-wing inspections in accordance with the time 
requirements listed in Section 2, Part 2 of PW JT9D SB No. 5749, 
Revision 8, dated October 30, 1998.
    (2) For engines on-wing that have had the diffuser case rear 
rail FPI or ECI inspected using the procedures referenced in PW JT9D 
SB No. 5749, Revision 4, dated May 10, 1993; Revision 5, dated 
September 29, 1995; Revision 6, dated May 8, 1998; Revision 7, dated 
August 19, 1998; or Revision 8, dated October 30, 1998; Section 2, 
Part 1 A (1)-(3), perform initial and repetitive on-wing inspections 
in accordance with PW JT9D SB 5749, Revision 8, dated October 30, 
1998, within the time requirements listed in Section 2, Part 2 of 
that SB, except as provided in paragraph (a) (4) of this AD.
    (3) Remove from service diffuser cases that do not meet the 
return to service criteria stated in PW JT9D SB No. 5749, Revision 
8, dated October 30, 1998, Section 2, Part 2 D, and replace with 
serviceable parts.
    (4) For engines that are overdue for an inspection on the 
effective date of this AD, accomplish the required inspection within 
25 cycles in service of the effective date of this AD.
    (b) 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. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Engine Certification Office.

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

    (c) Special flight permits may be issued in accordance with 
Secs. 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 accomplished.
    (d) The actions required by this AD shall be accomplished in 
accordance with the following Pratt & Whitney SB:

----------------------------------------------------------------------------------------------------------------
           Document No.                           Pages                Revision                Date
----------------------------------------------------------------------------------------------------------------
5749..............................  1, 2............................          8  October 30, 1998.
                                    3...............................          6  May 8, 1998.
                                    4...............................          7  August 19, 1998.
                                    5-7.............................          6  May 8, 1998.
                                    8, 9............................          8  October 30, 1998.
                                    10, 11..........................          6  May 8, 1998.
                                    12..............................          7  August 19, 1998.
                                    13-18...........................          6  May 8, 1998.
Total pages: 18.
----------------------------------------------------------------------------------------------------------------

    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Pratt & Whitney, Publication 
Department, Supervisor Technical Publications Distribution, M/S 132-
30, 400 Main St., East Hartford, CT 06108; telephone (860) 565-7700, 
fax (860) 565-4503. Copies may be inspected at the FAA, New England 
Region, Office of Regional Counsel, 12 New England Executive Park, 
Burlington, MA; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (e) This amendment becomes effective on July 26, 1999.

Issued in Burlington, Massachusetts, on May 18, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-13322 Filed 5-25-99; 8:45 am]
BILLING CODE 4910-13-U