[Federal Register Volume 61, Number 190 (Monday, September 30, 1996)]
[Rules and Regulations]
[Pages 50984-50988]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-22769]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-ANE-37; Amendment 39-9732; AD 96-18-08]
Airworthiness Directives; Pratt & Whitney PW2000 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 Pratt & Whitney PW2000 series turbofan engines, that
requires a reduction in the cyclic service life limit for hubs, disks,
airseals, blade retaining plates, and airsealing ring supports on
certain high pressure turbines (HPT) and low pressure turbines (LPT),
and provides for optional inspections for cracks or rework of certain
HPT and LPT hardware in order to retain the original, higher cyclic
service life limit for these components. This amendment is prompted in
part by new temperature data from engine testing, which were used in
recalculating stress levels, and resulted in a change to the calculated
cyclic service life limit. The actions specified by this AD are
intended to prevent HPT or LPT failure, which may result in an
uncontained engine failure and possible damage to the aircraft.
DATES: Effective November 29, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of November 29, 1996.
ADDRESSES: The service information referenced in this AD may be
obtained from Pratt & Whitney, Publications Department, Supervisor
Technical Publications Distribution, M/S 132-30, 400 Main St., East
Hartford, CT 06108; telephone (860) 565-7700, fax (860) 565-4503. This
information may be examined at the Federal Aviation Administration
(FAA), New England Region, Office of the Assistant Chief 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: John Fisher, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803-5299; telephone (617)
238-7149, fax (617) 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 Pratt & Whitney PW2000 series
turbofan engines was published in the Federal Register on October 16,
1995 (60 FR 53554). That action proposed to require a reduction in the
cyclic service life limit for hubs, disks, airseals, blade retaining
plates, and airsealing ring supports on certain HPT and LPT hardware,
and provide for optional inspections for cracks or rework of certain
HPT and LPT hardware in order to retain the original, higher cyclic
service life limit for these components.
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 states that the AD should be withdrawn. The commenter
states that life reductions are already provided in Chapter 05 of the
Engine Manual, thereby mandating the appropriate part lives.
Furthermore, the commenter states that by mandating the SBs in the AD,
all standard practices referenced within these SBs become mandated, so
that the overhaul shops will be required to obtain multiple alternative
methods of compliance, since their shop practices may be different than
those referenced in the AD. The FAA does not concur. Service life
limits that appear as airworthiness limitations at the time of type-
[[Page 50985]]
certification can be changed to more restrictive limits only by way of
rulemaking through an Airworthiness Directive. A change to the service
bulletin alone will not mandate a new, more restrictive, life limit.
While the new limits will typically appear in service instructions or
manuals before an AD is published, the FAA must complete the change by
publishing an AD. Regarding the commenter's issue on obtaining multiple
alternative methods of compliance, the FAA has revised this final rule
to permit certain applicable earlier revisions to various SBs.
Relative to the issue of SB standard shop practice references being
different than those employed by the airlines and overhaul shops, the
FAA recommends the commenter obtain alternate methods of compliance for
their shop practices that are relevant to the requirements of this AD.
One commenter states that the AD should be revised to agree with
the requirements of PW Alert Service Bulletin (ASB) No. PW2000 72-450,
Revision 5, dated May 28, 1994. Paragraph (e) in the compliance section
of the NPRM states that the initial inspection must be performed prior
to 6,000 total part cycles (TPC). The AD should be revised to allow
first run hubs to continue in service up to 7,500 TPC prior to initial
inspection. The FAA concurs and has revised this final rule
accordingly.
The commenter also states that paragraph (e) should be revised to
require the initial inspection prior to 7,500 TPC, and suggests a
wording change to better align the wording and intent with PW ASB No.
PW2000 72-450, Revision 5, dated May 28, 1994. The FAA concurs in part.
The initial inspection has been revised in this final rule to be
performed prior to 7,500 TPC, but the FAA believes that the compliance
structure in the NPRM is clearer than that proposed by the commenter,
and has therefore not revised the wording in this final rule.
The FAA has determined that the new, reduced life limits imposed by
this AD will not adversely affect fleet scheduling or result in
grounded aircraft due to the fact that these limits have already been
published in Chapter 05 of the applicable Engine Manuals, Airworthiness
Limitation Section, and operators have been notified previously in a
timely manner. Therefore, this AD does not include a phase-in period or
drawdown schedule of affected components.
Since issuance of the NPRM, PW has issued ASB No. PW2000 A72-450,
Revision 6, dated July 9, 1996. This final rule references this latest
as well as the previous revisions.
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.
There are approximately 650 engines of the affected design in the
worldwide fleet. The FAA estimates that 600 engines installed on
aircraft of U.S. registry will be affected by this AD, and that no
additional labor costs will be incurred by the fleet since inspection
and replacement intervals fall within the normal maintenance and
overhaul periods. Therefore, the FAA has determined that there would be
no additional cost impact on U.S. operators.
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.
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
96-18-08 Pratt & Whitney: Amendment 39-9732. Docket 95-ANE-37.
Applicability: Pratt & Whitney Models PW2037, PW2037(M), PW2040,
PW2240, and PW2337 turbofan engines installed on but not limited to
Boeing 757 series and Ilyushin IL96 series aircraft.
Note: 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 (o) 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 high pressure turbine (HPT) or low pressure turbine
(LPT) failure, which may result in an uncontained engine failure and
possible damage to the aircraft, accomplish the following:
(a) Remove from service 1st stage HPT disks, Part Number (P/N)
1A5301, prior to exceeding 5,000 total part cycles since new (TPC),
if installed with blade retaining plate, P/N 1A6998, and replace
with serviceable parts. If blade retaining plate, P/N 1A6998, has
not been installed on disk, P/N 1A5301, the disk may accumulate
15,000 TPC prior to removal from service.
(b) Remove from service 1st stage HPT blade retaining plates, P/
N 1A6998, prior to exceeding 5,000 TPC, and replace with serviceable
parts. If rework is accomplished prior to exceeding 5,000 TPC in
accordance with the Accomplishment Instructions of PW Alert Service
Bulletin (ASB) No. PW2000 A72-82, Revision 1, dated April 25, 1986;
Revision 2, dated July 17, 1986; Revision 3, dated November 7, 1986;
or Revision 4, dated June 18, 1987, and reidentified as assembly P/N
1B2373, the blade retaining plate may accumulate 15,000 TPC prior to
removal from service.
(c) Remove from service 2nd stage HPT blade retaining plates, P/
N 1B0450, prior to exceeding 7,000 TPC, and replace with serviceable
parts.
(d) Remove from service 2nd stage HPT blade retaining plates, P/
N 1B0945 (assembly P/N 1B0947), and replace with serviceable parts,
in accordance with the
[[Page 50986]]
Accomplishment Instructions of PW ASB No. PW2000 A72-228, Revision
2, dated May 10, 1988; Revision 3, dated August 25, 1988; or
Revision 4, dated November 9, 1988, as follows:
(1) Prior to exceeding 5,000 TPC, for retaining plates that have
not been inspected in accordance with the Accomplishment
Instructions of the above ASB prior to 3,000 TPC.
(2) Prior to exceeding 8,000 TPC, for retaining plates that have
been inspected in accordance with the Accomplishment Instructions of
the above ASB prior to 3,000 TPC.
(e) Remove from service 2nd stage HPT hubs, P/N's 1A8302,
1B1002, 1B1202, or 1B4902 prior to exceeding 7,500 TPC, and replace
with serviceable hubs. Hubs may accumulate 15,000 TPC prior to
removal from service if they are inspected at intervals that do not
exceed 6,000 cycles in service since last inspection, in accordance
with the Accomplishment Instructions of PW Service Bulletin (SB) No.
PW2000 72-450, Original, dated March 13, 1992; Revision 1, dated
March 26, 1992; Revision 2, dated April 7, 1992; Revision 3, dated
May 29, 1992; Revision 4, dated August 28, 1992; Revision 5, dated
May 28, 1994; or Revision 6, dated July 9, 1996.
(f) Remove from service 2nd stage HPT hubs, P/N 1B6602, prior to
exceeding 7,500 TPC, and replace with serviceable hubs. Hubs may
accumulate 15,000 TPC prior to removal from service if hub
assemblies are inspected prior to 7,500 TPC to verify scarf cut
blades are installed and to inspect the blade platform rail fillet
radii dimensions, in accordance with the Accomplishment Instructions
of PW SB No. PW2000 72-501, dated September 30, 1993. Hub assemblies
found with non-scarf cut blades must be reinspected at intervals not
to exceed 6,000 TPC since last inspection. Blades found with under
minimum rail fillet radii dimensions must be scrapped.
(g) Remove from service HPT lenticular airseal, P/N 1A8209,
prior to exceeding 4,000 TPC, and replace with serviceable airseals.
Airseals may accumulate 15,000 TPC prior to removal from service if:
(1) Inspected prior to exceeding 4,000 TPC, and thereafter
inspected at intervals not to exceed 250 cycles in service since
last inspection, in accordance with Compliance Paragraph E of the
Accomplishment Instructions of PW ASB No. PW2000 A72-220, Revision
3, dated April 13, 1989, or Revision 4, dated September 20, 1989; or
(2) The 2nd stage HPT case and vane assembly is reworked and
reidentified prior to exceeding 4,000 TPC, in accordance with the
Accomplishment Instructions of PW SB No. PW2000 72-233, Revision 2,
dated September 27, 1988, or Revision 3, dated May 30, 1989.
(h) For PW2037, PW2037(M), and PW2337 model engines, remove from
service 4th stage LPT disks, P/N's 8A1024, 8A1534, or 8A2137 prior
to exceeding 17,000 TPC, and replace with serviceable disks.
(i) For PW2040 and PW2240 model engines, remove from service 4th
stage LPT disks, P/N's 8A1534 or 8A2137, prior to exceeding 15,000
TPC, and replace with serviceable disks.
(j) Remove from service 3rd stage LPT airsealing ring supports,
P/N 8A1783, and replace with serviceable parts, as follows:
(1) For PW2040 and PW2240 model engines, prior to exceeding
15,000 TPC.
(2) For PW2037, PW2037(M), and PW2337 model engines, prior to
exceeding 17,000 TPC. Airsealing ring supports may accumulate 20,000
TPC prior to removal from service if they were fluorescent penetrant
inspected in accordance with Section 72-53-00 of PW2000 Engine
Manual, P/N 1A6231.
(k) For PW2037, PW2037(M), and PW2337 model engines, remove from
service prior to exceeding 17,000 TPC, and replace with serviceable
parts, as follows:
(1) 4th stage LPT airseal, P/N's 8A1014 or 8A1805.
(2) 5th stage LPT airseal, P/N's 8A1015 or 8A1806.
(3) 7th stage LPT airseal, P/N's A8A1017, A8A1808, 8A2097, or
A8A2097.
(l) Parts listed in paragraph (k) of this AD may accumulate
20,000 TPC prior to removal from service if they were fluorescent
penetrant inspected for cracks between 12,000 TPC and 17,000 TPC in
accordance with Section 72-53-00 of PW2000 Engine Manual, P/N
1A6231.
(m) For PW2040 and PW2240 model engines, remove from service
prior to exceeding 15,000 TPC, and replace with serviceable parts,
as follows:
(1) 4th stage LPT airseal, P/N's 8A1014 or 8A1805.
(2) 5th stage LPT airseal, P/N's 8A1015 or 8A1806.
(3) 7th stage LPT airseal, P/N's A8A1017, A8A1808, 8A2097, or
A8A2097.
(n) Parts listed in paragraph (m) of this AD may accumulate the
following TPC prior to removal if they were fluorescent penetrant
inspected for cracks between 10,000 TPC and 15,000 TPC in accordance
with Section 72-53-00 of PW2000 Engine Manual, P/N 1A6231.
(1) 4th stage LPT airseal, P/N's 8A1014 or 8A1805, prior to
exceeding 18,000 TPC.
(2) 5th stage LPT airseal, P/N's 8A1015 or 8A1806, prior to
exceeding 19,000 TPC.
(3) 7th stage LPT airseal, P/N's A8A1017, A8A1808, 8A2097, or
A8A2097, prior to exceeding 20,000 TPC, accomplish the following:
(o) 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. The
request should be forwarded through an appropriate FAA Principal
Maintenance Inspector, who may add comments and then send it to the
Manager, Engine Certification Office.
Note: Information concerning the existence of approved
alternative methods of compliance with this airworthiness directive,
if any, may be obtained from the Engine Certification Office.
(p) Special flight permits may be issued in accordance with
sections 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.
(q) The actions required by this AD shall be done in accordance
with the following PW service documents:
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Document No. Pages Revision Date
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ASB No. PW2000 A72-82.......... 1 1 April 25, 1986.
2-6 Original June 7, 1985.
7-9 1 April 25, 1986.
10 Original June 7, 1985.
11 1 April 25, 1986.
Total Pages: 11.
ASB No. PW2000 A72-82.......... 1 2 July 17, 1986.
2-6 Original June 7, 1985.
7-9 1 April 25, 1986.
10 Original June 7, 1985.
11 2 July 17, 1986.
Total Pages: 11.
ASB No. PW2000 A72-82.......... 1-4 3 November 7, 1986.
5,6 Original June 7, 1985.
7-14 3 November 7, 1986.
Total Pages: 14
ASB No. PW2000 A72-82.......... 1 4 June 18, 1987.
2-4 3 November 7, 1986.
5,6 Original June 7, 1985.
7-12 3 November 7, 1986.
13 4 June 18, 1987.
[[Page 50987]]
14 3 November 7, 1986.
Total Pages: 14.
ASB No. PW2000 A72-228......... 1 2 May 10, 1988.
2 Original July 6, 1987.
3 2 May 10, 1988.
4 1 March 29, 1988.
5-26 2 May 10, 1988.
Total Pages: 26.
ASB No. PW2000 A72-228......... 1 3 August 25, 1988.
2 Original July 6, 1987.
3 2 May 10, 1988.
4 3 August 25, 1988.
5-19 2 May 10, 1988.
20 3 August 25, 1988.
21,22 2 May 10, 1988.
23 3 August 25, 1988.
24-26 2 May 10, 1988.
Total Pages: 26.
ASB No. PW2000 A72-228......... 1 4 November 9, 1988.
2 Original July 6, 1987.
3 4 November 9, 1988.
4 3 August 25, 1988.
5-19 2 May 10, 1988.
20 3 August 25, 1988.
21,22 2 May 10, 1988.
23 3 August 25, 1988.
24-26 4 November 9, 1988.
Total Pages: 26.
SB No. PW2000 72-450........... 1-26 Original March 13, 1992.
Total Pages: 26.
SB No. PW2000 72-450........... 1 1 March 26, 1992.
2-11 Original March 13, 1992.
12,13 1 March 26, 1992.
14,15 Original March 13, 1992.
16,17 1 March 26, 1992.
18-21 Original March 13, 1992.
22,23 1 March 26, 1992.
24,25 Original March 13, 1992.
26 1 March 26, 1992.
Total Pages: 26.
SB No. PW2000 72-450........... 1 2 April 7, 1992.
2,3 Original March 13, 1992.
4,5 2 April 7, 1992.
6-11 Original March 13, 1992.
12 1 March 26, 1992.
13 2 April 7, 1992.
14,15 Original March 13, 1992.
16,17 1 March 26, 1992.
18-21 Original March 13, 1992.
22,23 1 March 26, 1992.
24,25 Original March 13, 1992.
26 1 March 26, 1992.
Total Pages: 26.
SB No. PW2000 72-450........... 1-5 3 May 29, 1992.
6-11 Original March 13, 1992.
12 1 March 26, 1992.
13 3 May 29, 1992.
14 Original March 13, 1992.
15-29 3 May 29, 1992.
Total Pages: 29.
ASB No. PW2000 72-450.......... 1 4 August 28, 1992.
2-5 3 May 29, 1992.
6-11 Original March 13, 1992.
12 1 March 26, 1992.
13 3 May 29, 1992.
14 Original March 13, 1992.
15 4 August 28, 1992.
16 3 May 29, 1992.
17 4 August 28, 1992.
18-29 3 May 29, 1992.
Total Pages: 29.
ASB No. PW2000 72-450.......... 1 5 May 28, 1994.
2 4 May 28, 1994.
3-5 3 May 29, 1992.
[[Page 50988]]
6-11 Original March 13, 1992.
12 1 March 26, 1992.
13 3 May 29, 1992.
14 Original March 13, 1992.
15 4 August 28, 1992.
16 3 May 29, 1992.
17 4 August 28, 1992.
18-29 3 May 29, 1992.
Total Pages: 29.
ASB No. PW2000 72-450.......... 1 6 July 9, 1996.
2 4 May 28, 1994.
3-5 3 May 29, 1992.
6-11 Original March 13, 1992.
12 1 March 26, 1992.
13 3 May 29, 1992.
14 Original March 13, 1992.
15 4 August 28, 1992.
16 3 May 29, 1992.
17 4 August 28, 1992.
18-28 3 May 29, 1992.
29 6 July 9, 1996.
Total Pages: 29.
SB No. PW2000 72-501........... 1-12 Original September 30, 1993.
Total Pages: 12.
ASB No. PW2000 A72-220......... 1 3 April 13, 1989.
2 1 July 29, 1987.
3-26 3 April 13, 1989.
Total Pages: 26.
ASB No. PW2000 A72-220......... 1 4 September 20, 1989.
2 1 July 29, 1987.
3-6 3 April 13, 1989.
7-9 4 September 20, 1989.
10-16 3 April 13, 1989.
17-27 4 September 20, 1989.
Total Pages: 27.
SB No. PW2000 72-233........... 1,2 2 September 27, 1988.
3-7 Original August 7, 1987.
8 1 January 22, 1988.
9,10 2 September 27, 1988.
Total Pages: 10.
SB No. PW2000 72-233........... 1-4 3 May 30, 1989.
5 Original August 7, 1987.
6 3 May 30, 1989.
7 Original August 7, 1987.
8 1 January 22, 1988.
9,10 3 May 30, 1989.
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, Technical
Publications Department, M/S 132-30, 400 Main Street, East Hartford,
CT 06108; telephone (860) 565-7700. Copies may be inspected at the
FAA, New England Region, Office of the Assistant Chief Counsel, 12
New England Executive Park, Burlington, MA; or at the Office ofthe
Federal Register, 800 North Capitol Street NW., suite 700,
Washington, DC.
(r) This amendment becomes effective on November 29, 1996.
Issued in Burlington, Massachusetts, on August 26, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 96-22769 Filed 9-27-96; 8:45 am]
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