Airworthiness Directives; Pratt & Whitney Turbofan Engines

[Federal Register Volume 80, Number 139 (Tuesday, July 21, 2015)]
[Rules and Regulations]
[Pages 43011-43012]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-17710]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2014-1127; Directorate Identifier 2014-NE-16-AD; 
Amendment 39-18203; AD 2015-14-05]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule.

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

SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Pratt & Whitney (PW) JT8D-217C and JT8D-219 turbofan engines. This AD 
was prompted by reports of cracking in the low-pressure turbine (LPT) 
shaft. This AD requires removing affected LPT shafts from service using 
a drawdown plan. We are issuing this AD to prevent failure of the LPT 
shaft, which could lead to an uncontained engine failure and damage to 
the airplane.

DATES: This AD is effective August 25, 2015.

ADDRESSES: For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-8770; 
fax: 860-565-4503. You may view this service information at the FAA, 
Engine & Propeller Directorate, 12 New England Executive Park, 
Burlington, MA. For information on the availability of this material at 
the FAA, call 781-238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2014-
1127; or in person at the Docket Management Facility between 9 a.m. and 
5 p.m., Monday through Friday, except Federal holidays. The AD docket 
contains this AD, the regulatory evaluation, any comments received, and 
other information. The address for the Docket Office (phone: 800-647-
5527) is Document Management Facility, U.S. Department of 
Transportation, Docket Operations, M-30, West Building Ground Floor, 
Room W12-140, 1200 New Jersey Avenue SE., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Jo-Ann Theriault, Aerospace Engineer, 
Engine Certification Office, FAA, Engine & Propeller Directorate, 12 
New England Executive Park, Burlington, MA 01803; phone: 781-238-7105; 
fax: 781-238-7199; email: [email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR 
part 39 by adding an AD that would apply to all PW JT8D-217C and JT8D-
219 turbofan engines. The NPRM published in the Federal Register on 
March 2, 2015 (80 FR 11140). The NPRM was prompted by in-shop findings 
of fatigue cracks on the No. 4.5 bearing thread undercut adjacent to 
the oil feed holes. The cracks were discovered during routine 
fluorescent penetrant inspections (FPIs). Both shafts had oil feed hole 
enlargement rework accomplished. The root cause is increased stress on 
the fillet of the thread undercut region in front of the oil feed holes 
caused by oil feed hole rework. The increased stress reduces the low 
cycle fatigue life of the shaft. The NPRM proposed to require removing 
affected LPT shafts from service using a drawdown plan. We are issuing 
this AD to prevent failure of the LPT shaft, which could lead to an 
uncontained engine failure and damage to the airplane.

Related Service Information

    We reviewed PW Service Bulletin (SB) No. JT8D 6504, dated November 
5, 2014. The SB contains additional information regarding removal of 
the LPT shaft.

Comments

    We gave the public the opportunity to participate in developing 
this AD. The following presents the comments received on the NPRM (80 
FR 11140, March 2, 2015) and the FAA's response to each comment.

Request To Withdraw the NPRM

    Delta Air Lines (DAL) and Allegiant Air requested that the current 
LPT shaft life limit of 25,000 cycles-since-new (CSN) be retained 
rather than removing the LPT shaft from service at 20,000 CSN as 
proposed in the NPRM. The commenters stated that reducing the life 
limit is unjustified because there has not been an in-service LPT shaft 
failure of the type addressed.
    We do not agree. We determined that an acceptable level of safety 
would not be maintained if LPT shafts are allowed to remain in service 
until accumulating 25,000 CSN. We reduced the life of the LPT shaft to 
20,000 CSN to minimize the risk of LPT shaft failure. We did not change 
this AD.

Proposal To Increase Repetitive Inspections

    DAL and Allegiant Air proposed increasing the occurrence of FPIs to 
increase the opportunity of identifying LPT shaft cracks. The 
commenters stated that routine FPIs have been successful in detecting 
LPT shaft cracks in the past.
    We do not agree. Recurring inspections are not adequate as a final 
corrective action. Relying on recurring FPIs to detect cracks, rather 
than shaft removal at 20,000 CSN, would likely result in an increased 
number of LPT shafts cracking in service, a greater risk of undetected 
cracked shafts being returned to service, and an unacceptable risk of 
shaft failure. We determined that long-term continued operational 
safety is enhanced by a terminating action that removes affected shafts 
from service rather than by increasing the occurrence of repetitive 
inspections. We did not change this AD.

Request To Reduce Costs

    DAL and Allegiant Air requested retaining the existing life limit 
or increasing the occurrence of inspections. The commenters stated that 
the life reduction in the NPRM places an undue economic burden on the 
U.S. fleet by forcing early engine removals.
    We do not agree. We mitigated the operational and financial impacts 
by providing a drawdown plan rather than requiring removal before 
further flight, while providing an acceptable level of safety. We did 
not change this AD.

Conclusion

    We reviewed the relevant data, considered the comments received, 
and determined that air safety and the public interest require adopting 
this AD as proposed.

Costs of Compliance

    We estimate that this AD will affect about 744 engines installed on 
airplanes of U.S. registry. The average labor rate is $85 per hour. We 
estimate the pro-rated replacement cost would be $28,230. We also 
estimate that shaft replacement would be accomplished during an engine 
shop visit at no additional labor cost. Based on these figures, we 
estimate the cost of the proposed AD on U.S. operators to be 
$21,003,120.

[[Page 43012]]

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    This AD will not have federalism implications under Executive Order 
13132. This AD will not have a substantial direct effect 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.
    For the reasons discussed above, I certify that this AD:
    (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),
    (3) Will not affect intrastate aviation in Alaska to the extent 
that it justifies making a regulatory distinction, and
    (4) 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.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

2015-14-05 Pratt & Whitney: Amendment 39-18203; Docket No. FAA-2014-
1127; Directorate Identifier 2014-NE-16-AD.

(a) Effective Date

    This AD is effective August 25, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Pratt & Whitney (PW) JT8D-217C and JT8D-
219 turbofan engines with low-pressure turbine (LPT) shaft part 
numbers 783319, 783319-001, 783319-003, 783319-004, 783320, 783320-
001, 783320-003, 783320-004, 820514-001, 820514-003, 820514-004, or 
820514-005, installed.

(d) Unsafe Condition

    This AD was prompted by reports of cracking in the LPT shaft. We 
are issuing this AD to prevent failure of the LPT shaft, which could 
lead to an uncontained engine failure and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) If the LPT shaft has 15,000 or fewer cycles-since-new (CSN) 
on the effective date of this AD, remove it from service before it 
accumulates 20,000 CSN.
    (2) If the LPT shaft has more than 15,000 CSN on the effective 
date of this AD, remove it from service before it accumulates 5,000 
additional cycles in service, or at the next piece-part exposure 
after accumulating 20,000 CSN, whichever occurs first.
    (3) After the effective date of this AD, do not install any LPT 
shaft listed in paragraph (c) of this AD that is at piece-part 
exposure and exceeds the new life limit of 20,000 CSN, into any 
engine.

(f) Definition

    For the purpose of this AD, piece-part exposure is when the LPT 
shaft is completely disassembled from the engine.

(g) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, may approve AMOCs 
for this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: [email protected].

(h) Related Information

    (1) For more information about this AD, contact Jo-Ann 
Theriault, Aerospace Engineer, Engine Certification Office, FAA, 
Engine & Propeller Directorate, 12 New England Executive Park, 
Burlington, MA 01803; phone: 781-238-7105; fax: 781-238-7199; email: 
[email protected].
    (2) PW Service Bulletin No. JT8D 6504, dated November 5, 2014, 
which is not incorporated by reference in this AD, can be obtained 
from PW using the contact information in paragraph (h)(3) of this 
AD.
    (3) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-
8770; fax: 860-565-4503.
    (4) You may view this service information at the FAA, Engine & 
Propeller Directorate, 12 New England Executive Park, Burlington, 
MA. For information on the availability of this material at the FAA, 
call 781-238-7125.

(i) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on June 26, 2015.
Ann C. Mollica,
Acting Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-17710 Filed 7-20-15; 8:45 am]
 BILLING CODE 4910-13-P

The complete text was extracted from the official GovInfo HTML edition for this publication. Acquired 2026-10-09T02:33:09.049030+00:00. Text extraction preserves the recorded source wording; it does not determine current requirements.

Open the captured official edition

Source SHA-256

7a4d3f264e2b4094141ef075305b0013d0e1dd006f1d79351faed477fcc1d5bb

Text SHA-256

a4910d92237e452c167368dd4c3296844abf122580c29fff0fba1e7b104f8eea