[Federal Register Volume 61, Number 161 (Monday, August 19, 1996)]
[Rules and Regulations]
[Pages 42781-42782]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21033]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-ANE-19; Amendment 39-9714; AD 96-15-06]
RIN 2120-AA64
Airworthiness Directives; Pratt & Whitney JT8D-200 Series
Turbofan Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule, request for comments.
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SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) 96-15-06 that was sent previously
to all known U.S. owners and operators of Pratt & Whitney (PW) JT8D-200
series turbofan engines by individual letters. This AD requires, prior
to further flight, removal from service all affected fan hubs,
identified by serial number, and replacement with serviceable parts.
This amendment is prompted by a report of an accident involving an
uncontained failure of a stage 1 fan hub. The actions specified by this
AD are intended to prevent the initiation and propagation of a fatigue
crack, fracture of the fan hub, uncontained engine failure, and damage
to the aircraft.
DATES: Effective September 3, 1996, to all persons except those persons
to whom it was made immediately effective by priority letter AD 96-15-
06, issued on July 16, 1996, which contained the requirements of this
amendment.
Comments for inclusion in the Rules Docket must be received on or
before October 18, 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-19, 12 New England
Executive Park, Burlington, MA 01803-5299. Comments may also be
submitted to the Rules Docket by using the following Internet address:
epd-adcomments@mail.hq.faa.gov''. All comments must contain the
Docket No. in the subject line of the comment.
FOR FURTHER INFORMATION CONTACT: Robert E. Guyotte, Manager, Engine
Certification Branch, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803-5299; telephone (617) 238-
7142, fax (617) 238-7199.
SUPPLEMENTARY INFORMATION: On July 16, 1996, the Federal Aviation
Administration (FAA) issued priority letter airworthiness directive
(AD) 96-15-06, applicable to Pratt & Whitney (PW) JT8D-200 series
engines, which requires, prior to further flight, removal from service
all affected fan hubs, identified by serial number, and replacement
with serviceable parts. That action was prompted by a report of an
accident involving an uncontained failure of a stage 1 fan hub. A fan
hub failure poses a serious threat to safety of flight due to the
possibility of high energy engine fragments penetrating the aircraft
fuselage. The reported fan hub failure resulted from a fatigue crack
that originated in a tie bolt hole. The fatigue crack initiated from
mechanical surface damage produced during machining of the tie bolt
holes, and propagated in a low cycle fatigue mode due to normal engine
start-stop cycles. The manufacturing records indicate that a surface
anomaly was observed in a tie bolt hole during the Blue Etch Anodize
inspection which was determined to be acceptable. The manufacturing
records indicate that six other hubs with similar anomalies in the tie
bolt holes were installed on engines in revenue service. The FAA has
determined that all hubs that exhibited surface anomalies during
inspection of the type observed on the accident hub are not acceptable
and must be removed from service, and replaced with a serviceable part
prior to further flight. This condition, if not corrected, could result
in the initiation and propagation of a fatigue crack, fracture of the
fan hub, uncontained engine failure, and damage to the aircraft.
The FAA is continuing the investigation and based on investigative
findings, further rulemaking action may be required.
Since the unsafe condition described is likely to exist or develop
on other engines of the same type design, the FAA issued priority
letter AD 96-15-06 to prevent fracture of the fan hub, uncontained
engine failure, and damage to the aircraft. The AD requires, prior to
further flight, removal from service all affected fan hubs, Part Number
(P/N) 5000501-01, identified by any of the following Serial Numbers:
T50693, T50823, T50827, R32926, R32960, P66756, and replacement with
serviceable parts. The FAA determined this compliance time based on the
potential severity of the aircraft hazard in the event of a fan hub
failure, in conjunction with evidence of tie bolt hole surface
anomalies during manufacturing inspection.
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment thereon were
impracticable and contrary to the public interest, and good cause
existed to make the AD effective immediately by individual letters
issued on July 16, 1996, to all known U.S. owners and operators of PW
JT8D-200 series turbofan engines. These conditions still exist, and the
AD is hereby published in the Federal Register as an amendment to
Section 39.13 of part 39 of the Federal Aviation Regulations (14 CFR
part 39) to make it effective to all persons.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting flight safety and, thus, was not preceded by
notice and an opportunity for public comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All
communications received on or before the closing date for comments will
be considered, and this rule may be amended in light of the comments
received. Factual information that supports the commenter's ideas and
suggestions is extremely helpful in evaluating the effectiveness of the
AD action and determining whether additional rulemaking action would be
needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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 that
summarizes each FAA-public contact concerned with the substance of this
AD 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
[[Page 42782]]
statement is made: ``Comments to Docket Number 96-ANE-19.'' The
postcard will be date stamped and returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866. It has been determined further that this
action involves an emergency regulation under DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979). If it is determined
that this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket. A copy of it, if filed, 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, 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:
96-15-06 Pratt & Whitney: Amendment 39-9714. Docket 96-ANE-19.
Applicability: Pratt & Whitney (PW) JT8D-200 series turbofan
engines incorporating affected first stage fan hubs, Part Number (P/
N) 5000501-01, identified by any of the following Serial Numbers:
T50693, T50823, T50827, R32926, R32960, P66756.
These engines are 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 (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 the initiation and propagation of a fatigue crack,
fracture of the fan hub, uncontained engine failure, and damage to
the aircraft, accomplish the following:
(a) Prior to further flight, remove from service all affected
first stage fan hubs, P/N 5000501-01, identified by Serial Numbers
listed in the applicability paragraph of this AD, and replace with
serviceable parts.
(b) An alternative method of compliance or adjustment of
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.
(c) This amendment becomes effective September 3, 1996, to all
persons except those persons to whom it was made immediately
effective by priority letter AD 96-15-06, issued July 16, 1996,
which contained the requirements of this amendment.
Issued in Burlington, Massachusetts, on August 7, 1996.
Jay J. Pardee,
Manager, Engine and Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 96-21033 Filed 8-16-96; 8:45 am]
BILLING CODE 4910-13-P
