[Federal Register Volume 64, Number 136 (Friday, July 16, 1999)]
[Rules and Regulations]
[Pages 38299-38301]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-17555]
[[Page 38299]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-ANE-31-AD; Amendment 39-11221; AD 99-15-02]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT9D Series Turbofan
Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Pratt & Whitney (PW) JT9D series turbofan
engines, that requires initial and repetitive in-shop eddy current and
on-wing ultrasonic inspections of the Combustion Chamber Outer Casing
(CCOC) forward flange (L-flange) fillet radius for cracking, and
replacing cracked L-flanges with serviceable parts. Replacement with an
improved L-flange constitutes terminating action to the repetitive
inspections. This amendment is prompted by reports of CCOC rupture due
to cracking in the L-flange fillet radius. The actions specified by the
proposed AD are intended to prevent CCOC rupture due to cracking, which
could result in an uncontained engine failure and damage to the
aircraft.
DATES: Effective date August 16, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 16, 1999.
ADDRESSES: The service information referenced in this AD may be
obtained from Pratt & Whitney, 400 Main St., East Hartford, CT 06108;
telephone (860) 565-8770, 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; 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 (781)
238-7128, fax (781) 238-7199.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Pratt & Whitney (PW) JT9D
series turbofan engines was published in the Federal Register on
December 21, 1998 (63 FR 70352). That action proposed to require
initial and repetitive in-shop eddy current and on-wing ultrasonic
inspections of the Combustion Chamber Outer Casing (CCOC) forward
flange (L-flange) fillet radius for cracking, and replacing cracked L-
flanges with serviceable parts.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
One commenter supports the proposed actions contained in the notice
of proposed rulemaking (NPRM).
One commenter notes that the aircraft applicability may be
incorrect because it includes the A300 Aircraft. The commenter believes
that the JT9D-7R4 is the only model being installed on the A300 and
that the service bulletin (SB) may be incorrect. The commenter is
correct. Pratt & Whitney indicates that the JT9D-3/-20 models were
never installed on the A300 Aircraft, and that the documents referenced
are in error. The Applicability paragraph has been changed accordingly.
The listing of aircraft installations in an AD that applies to engines,
however, is informative only and does not affect the applicability of
the AD to the identified engine models.
One commenter notes that Chromalloy makes a replacement CCOC under
a supplemental type certificate (STC) P/N CFL758479, that the FAA
should consider as acceptable terminating action to the AD. The
commenter also states that Chromalloy makes a replacement CCOC L-flange
under a parts manufacturing approval (PMA) which the commenter claims
is the equivalent to the flange introduced by PW SB 4482, and should
also be considered as acceptable terminating action for the AD. The FAA
agrees. These part numbers have been added to the list of parts whose
installation will constitute terminating actions to the AD in a new
paragraph (e).
One commenter utilizes Standard Practice Operating Procedure (SPOP)
82 florescent penetrant inspection (FPI) of the L-flange when the part
is in their shop. For cases that have used SPOP 82 FPI at last shop
visit, the commenter requests that the FAA extend the 250 cycle limit
to the 500 cycle limit for the initial on-wing inspection. The FAA does
not agree. The performance of SPOP 82, when compared to the required
ultrasonic inspection, does not raise the probability of detecting a
crack sufficiently to increase the initial inspection requirement from
250 cycles to 500 cycles.
One commenter requested that the effective date of the AD be
changed from 30 days after publication in the Federal Register to 60
days. The commenter states that he often receives the ADs weeks after
their publication date, leaving little time to update his tracking
system. The FAA does not agree. All AD's are published in the Federal
Register and are available on a subscription basis from the Government
Printing Office within days of publication. In addition, all ADs are
available on the Federal Register's Internet web site the day they are
published and are listed on the Federal Register's preview web site the
day before publication. Additionally, the FAA mails hard copies of ADs
to all registered owner/operators within a week of their publication in
the Federal Register.
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. 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 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
from 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.
[[Page 38300]]
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:
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:
99-15-02 Pratt & Whitney: Amendment 39-11221. Docket 98-ANE-31-AD.
Applicability: Pratt & Whitney (PW) JT9D-3A, -7, -7H, -7A, -7AH,
-7F, -7J, -20, and -20J series turbofan engines, with Combustion
Chamber Outer Casing (CCOC), part numbers (P/Ns) 644801, 693294,
709016, 729237, 729238, and 729239, installed. These engines are
installed on but not limited to certain models of Boeing 747 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 (h) 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 CCOC rupture due to cracking, which could result in
an uncontained engine failure and damage to the aircraft, accomplish
the following:
(a) Perform initial on-wing ultrasonic inspections of the CCOC
forward flange (L-flange) fillet radius for cracking in accordance
with PW Alert Service Bulletin (ASB) No. A6343 Revision 1, dated
October 8, 1998, as follows:
(1) For engines that have not had the L-flange fillet radius
eddy current inspected using the JT9D Engine Manual (P/N 646028, P/N
770407, P/N 770408, as appropriate) Revision No. 104; or Temporary
Revision No. 72-6517, Temporary Revision No. 72-6334, or Temporary
Revision No. 72-6206, all of which were superseded by manual
Revision No. 104; at the last shop visit, inspect within 250 cycles
in service (CIS) after the effective date of this AD, or the next
shop visit, whichever occurs first.
(2) For engines that did have the L-flange fillet radius eddy
current inspected using the JT9D Engine Manual (P/N 646028, P/N
770407, P/N 770408, as appropriate) Revision No. 104; or Temporary
Revision No. 72-6517, Temporary Revision No. 72-6334, or Temporary
Revision No. 72-6206, all of which were superseded by manual
Revision No. 104; at the last shop visit, inspect within 2,000 CIS,
or the next shop visit after the effective date of this AD,
whichever occurs first.
(b) Thereafter, ultrasonically inspect on-wing at intervals not
to exceed 500 CIS since last on-wing inspection in accordance with
PW Alert Service Bulletin (ASB) No. A6343 Revision 1, dated October
8, 1998, or 2000 cycles in service (CIS) since last in-shop ECI
inspection, whichever occurs later.
(c) If a crack is found during on-wing inspection, remove the
part from service, and replace with a serviceable part as follows:
(1) For cracks found to be over the inspection threshold limit,
but less than 2 inches, remove within 5 CIS.
(2) For cracks found to be over the inspection threshold limit
and equal to or greater than 2 inches, remove prior to further
flight.
(d) If a crack in the L-flange fillet radius of the CCOC is
found during in-shop inspection, remove the CCOC and replace with a
serviceable part or replace the L-flange with an improved L-flange
P/N 734515 or 056-1133-1 in accordance with the accomplishment
instructions of PW ASB No. 6343 Revision 1, dated October 8, 1998.
(e) Installation of CCOC's containing improved L-flange P/N's
734515 or 056-1133-1, or installation of CCOC's with P/N's 758479 or
CFL758479, constitute terminating action to the repetitive
inspection requirements of this AD.
(f) Inspect the CCOC L-flange fillet radius during every CCOC
shop visit in accordance with JT9D Engine Manual (P/N 646028, P/N
770407, P/N 770408, as appropriate) Revision No. 104 (or Temporary
Revision No. 72-6517, Temporary Revision No. 72-6334, or Temporary
Revision No. 72-6206, which were superseded by manual Revision No.
104); that details eddy current inspection procedures for the L-
flange fillet radius.
(g) For the purpose of this AD, a shop visit is defined as
anytime the L-flange is separated in the process of performing
engine repair.
(h) 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 request 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.
(i) 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.
(j) The inspections must be done in accordance with the
following Pratt & Whitney SBs:
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Document No. Pages Revision Date
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JT9D A6343.................... 1-5 Rev. 1............................. October 8, 1998.
6-9 Original........................... July 31, 1998.
10-11 Rev. 1............................. October 8, 1998.
12 Original........................... July 31, 1998.
13 Rev. 1............................. October 8, 1998.
Total Pages: 13.
4482.......................... 1 Rev. 1............................. July 8, 1976.
2 Original........................... September 5, 1975.
3 Rev. 1............................. July 8, 1976.
4 Original........................... September 5, 1975.
5 Rev. 1............................. July 8, 1976.
6-8 Original........................... September 5, 1975.
9 Rev. 1............................. July 8, 1976.
10 Original........................... September 5, 1975.
Total pages: 10.
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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, 400 Main St.,
East Hartford, CT 06108; telephone (860) 565-8770, fax (860) 565-
8770. Copies may be inspected at the FAA, New England Region, Office
of the Regional Counsel, 12 New
[[Page 38301]]
England Executive Park, Burlington, MA; or at the Office of the
Federal Register, 800 North Capitol Street, NW, suite 700,
Washington, DC.
(k) This amendment becomes effective on August 16, 1999.
Issued in Burlington, Massachusetts, on July 6, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. 99-17555 Filed 7-15-99; 8:45 am]
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