[Federal Register Volume 61, Number 194 (Friday, October 4, 1996)]
[Proposed Rules]
[Pages 51847-51849]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-25596]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-ANE-33]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D-200 Series 
Turbofan Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to Pratt & Whitney JT8D-200 series 
turbofan engines. This proposal would require, for front compressor 
front hubs (fan hubs), cleaning; initial and repetitive eddy current 
(ECI) and fluorescent penetrant inspections (FPI) of tierod and 
counterweight holes for cracks; removal of bushings; the cleaning and 
ECI and FPI of bushed holes for cracks; and, if necessary, replacement 
with serviceable parts. In addition, this proposal would require 
reporting findings of cracked fan hubs. This proposal is prompted by a 
report of an uncontained failure of a fan hub. The actions specified by 
the proposed AD are intended to prevent fan hub failure due to tierod, 
counterweight, or bushed hole cracking, which could result in an 
uncontained engine failure and damage to the aircraft.

DATES: Comments must be received by November 4, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 96-ANE-33, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may be inspected at 
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, 
except Federal holidays.
    The service information referenced in the proposed rule 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 FAA, New England Region, Office of the Assistant Chief 
Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Robert E. Guyotte, Manager, Engine 
Certification Branch, Engine Certification Office, FAA, Engine and 
Propeller Directorate, 12 New England Executive Park, Burlington, MA 
01803-5299; telephone (617) 238-7142, fax (617) 238-7199.

[[Page 51848]]

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 notice 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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 96-ANE-33.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 96-ANE-33, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    The Federal Aviation Administration (FAA) received a report of an 
uncontained failure of a front compressor front hub (fan hub), Part 
Number 5000501-01, installed on a Pratt & Whitney (PW) JT8D-200 series 
turbofan engine. The investigation revealed a localized work hardened 
layer found in the tierod hole of the fan hub from which a crack 
initiated and propagated to failure in low cycle fatigue. The FAA has 
determined that the work hardened layer was the result of a coolant 
channel drill using a single plunge drilling procedure during 
manufacture. This condition, if not corrected, could result in fan hub 
failure due to tierod or counterweight hole cracking, which could 
result in an uncontained engine failure and damage to the aircraft.
    The FAA has reviewed and approved the technical contents of PW 
Alert Service Bulletin (ASB) No. A6272, dated September 24, 1996, that 
describes procedures for cleaning and eddy current (ECI) and 
fluorescent penetrant (FPI) inspection of tierod and counterweight 
holes for cracks; removal of bushings; and the cleaning, FPI, and ECI 
of bushed holes for cracks. Even though the ASB contains three of the 
serial numbers (S/Ns) of the fan hubs that were removed from service in 
accordance with AD 96-15-06, the manufacturer has informed the FAA that 
these fan hubs have been destroyed during the investigation to confirm 
the failure mode.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would require cleaning, initial and repetitive ECI and FPI 
for cracks of tierod and counterweight holes; removing bushings; 
initial and repetitive ECI and FPI of bushed holes for cracks; and, if 
necessary, replacing with serviceable parts. The compliance 
requirements allow selection of inspection schedules depending on fan 
hub S/Ns listed in the ASB, and includes an inspection schedule for 
those fan hubs whose S/Ns are not listed in the ASB. In addition, this 
AD would require reporting findings of cracked fan hubs. The actions 
would be required to be accomplished in accordance with the ASB 
described previously.
    There are approximately 2,624 engines of the affected design in the 
worldwide fleet. The FAA estimates that 1,279 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD, that 
it would take approximately 20 work hours per engine for 360 engines to 
disassemble, remove, inspect, and reassemble engines, and 4 work hours 
per engine for 919 engines to inspect at piece- part exposure. 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 $862,560.
    The regulations proposed herein would 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 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Pratt & Whitney: Docket No. 96-ANE-33.

    Applicability: Pratt & Whitney (PW) JT8D-209, -217, -217C, and -
219 series turbofan engines, installed on but not limited to 
McDonnell Douglas MD-80 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 (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: Required as indicated, unless accomplished 
previously.
    To prevent front compressor front hub (fan hub), Part Number 
5000501-01, failure due to tierod, counterweight, or bushed hole 
cracking, which could result in an

[[Page 51849]]

uncontained engine failure and damage to the aircraft, accomplish 
the following:
    (a) Fan hubs with fewer than 4,000 cycles since new (CSN) on the 
effective date of this AD need not be inspected until accumulating 
4,000 CSN. After the effective date of this AD, upon accumulating 
4,000 CSN, perform the requirements of paragraph (b) of this AD.
    (b) For fan hubs with 4,000 CSN, accomplish the following:
    (1) For fan hubs identified by serial numbers (S/Ns) in Appendix 
A of PW Alert Service Bulletin (ASB) No. A6272, dated September 24, 
1996, inspect for cracks in accordance with the initial inspection 
intervals of Table 1 of this AD, in accordance with the 
Accomplishment Instructions, Paragraph A, Part 1, and, if 
applicable, Paragraph B, of PW ASB No. A6272, dated September 24, 
1996.
    (i) Fan hubs that have been initially inspected in accordance 
with paragraph (b)(1) of this AD must be reinspected in accordance 
with the reinspection requirements of the schedule selected for 
initial inspection.
    (ii) Reinspect for cracks in accordance with the reinspection 
intervals of Table 1 of this AD in accordance with the 
Accomplishment Instructions, Paragraph A, Part 1, and, if 
applicable, Paragraph B, of PW ASB No. A6272, dated September 24, 
1996.

                                 Table 1                                
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            Initial Inspection                      Reinspection        
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1. Within 1,050 cycles in service (CIS)     After accumulating 2,500 CIS
 after the effective date of this AD, or     since last inspection, but 
 prior to accumulating 5,050 CSN,            not to exceed 6,000 CIS    
 whichever occurs later.                     since last inspection.     
2. Within 990 CIS after the effective date  After accumulating 2,500 CIS
 of this AD, or prior to accumulating        since last inspection, but 
 4,990 CSN, whichever occurs later.          not to exceed 8,000 CIS    
                                             since last inspection.     
3. Within 965 CIS after the effective date  After accumulating 2,500 CIS
 of this AD, or prior to accumulating        since last inspection, but 
 4,965 CSN, whichever occurs later.          not to exceed 10,000 CIS   
                                             since last inspection.     
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    (2) For fan hubs with S/Ns not listed in Appendix A of PW ASB 
No. A6272, dated September 24, 1996, inspect at the next time the 
fan hub is in the shop at piece-part level, but not to exceed 10,000 
CIS after effective date of this AD in accordance with the 
Accomplishment Instructions, Paragraph A, Part 2, and, if 
applicable, Paragraph B, of PW ASB No. A6272, dated September 24, 
1996.
    (3) Remove from service fan hubs found cracked or exceed the 
bushed hole acceptance criteria in accordance with PW ASB No. A6272, 
dated September 24, 1996, and replace with serviceable parts.
    (c) Report findings of cracked fan hubs within 48 hours after 
inspection to Robert Guyotte, Manager, Engine Certification Branch, 
Engine Certification Office, FAA, Engine and Propeller Directorate, 
12 New England Executive Park, Burlington, MA 01803-5299; telephone 
(617) 238-7142, fax (617) 238-7199; Internet: 
Robert.G[email protected]. Reporting requirements have been 
approved by the Office of Management and Budget and assigned OMB 
control number 2120-0056.
    (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. 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.
    (e) 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.

    Issued in Burlington, Massachusetts, on September 27, 1996.
James C. Jones,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 96-25596 Filed 10-3-96; 8:45 am]
BILLING CODE 4910-13-U