[Federal Register Volume 65, Number 88 (Friday, May 5, 2000)]
[Proposed Rules]
[Pages 26152-26154]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11303]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NE-29-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D 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

[[Page 26153]]

& Whitney JT8D series turbofan engines. This proposal would require 
inspections of main fuel pump control shafts for excessive spline wear. 
Additionally, as terminating action to the inspections, this proposal 
would require the replacement of the main fuel pump control shaft with 
parts of improved design, and reworking the main fuel pump impeller, 
impeller gear train plate assembly, and impeller cover assembly. This 
proposal is prompted by reports of failed main fuel pump control shafts 
caused by excessive spline wear. The actions specified by the proposed 
AD are intended to prevent loss of engine throttle control, uncommanded 
acceleration, uncommanded deceleration or inflight shutdown, which 
could result in reduced airplane control during a critical phase of 
flight.

DATES: Comments must be received by July 5, 2000.

ADDRESSES: Submit comments to the Federal Aviation Administration 
(FAA), New England Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 99-NE-29-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299. Comments may also be sent via the Internet 
using the following address: ``[email protected]''. Comments sent 
via the Internet must contain the docket number in the subject line. 
Comments may be inspected at this location between 8 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 860-565-8770, fax 860-565-4503. This information may be 
examined at the FAA, New England Region, Office of the Regional 
Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; 
telephone 781-238-7175, fax 781-238-7199.

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 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 99-NE-29-AD.'' 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 Regional Counsel, 
Attention: Rules Docket No. 99-NE-29-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    The Federal Aviation Administration (FAA) has received 51 reports 
of failed main fuel pump control shafts, which resulted in the loss of 
engine throttle control, uncommanded acceleration, uncommanded 
deceleration or inflight shutdown, on Pratt & Whitney (PW) Models JT8D-
1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, and -15A turbofan 
engines. In one incident, a Boeing 737-200 powered by two PW Model 
JT8D-15 engines experienced an uncommanded acceleration of the No. 2 
engine during takeoff roll. The exhaust gas temperature (EGT) 
overtemperature indication light illuminated in the cockpit at 
approximately 110 knots. A takeoff abort was attempted but the No. 2 
engine did not respond to the throttle movement. The airplane went off 
the side of the runway, sustained landing gear damage, and was 
destroyed by fire after all passengers and crew escaped. Four 
passengers were injured during the evacuation. The investigation 
revealed a failed main fuel pump control shaft. The main fuel pump 
control shaft failure was attributed to wear of the main fuel pump 
control shaft spline. This condition, if not corrected, could result in 
the loss of engine throttle control, uncommanded acceleration, 
uncommanded deceleration or inflight shutdown, which could result in 
reduced aircraft control during a critical phase of flight.

Service Information

    The FAA has reviewed and approved the technical contents of PW 
Alert Service Bulletin (ASB) A6381 dated March 15, 2000, that describes 
procedures for inspecting the main fuel pump control shaft for 
excessive spline wear. As terminating action, PW ASB A6381 describes 
procedures for replacement of the main fuel pump control shaft with an 
improved wear resistant material shaft and reworking the main fuel pump 
impeller, impeller gear train plate assembly, and impeller cover 
assembly.
    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 inspecting main fuel pump control shafts for 
excessive wear, replacing the main fuel pump control shaft with parts 
of improved design, and reworking the main fuel pump impeller, impeller 
gear train plate assembly, and impeller cover assembly. The replacement 
and rework must be accomplished prior to accumulating 12,000 hours 
time-in-service (TIS) since last overhaul, or within 2,000 hours after 
the effective date of this AD, whichever occurs later. The actions 
would be required to be accomplished in accordance with the ASB 
described previously.
    There are approximately 5,800 engines of the affected design in the 
worldwide fleet. The FAA estimates that 2962 engines installed on 
aircraft of US registry would be affected by this proposed AD, that it 
would take approximately 0.3 work hours to perform the required 
inspections and 0.5 hours per engine to accomplish the replacements 
proposed at overhaul, and that the average labor rate is $60 per work 
hour. Required parts would cost approximately $3,996 per engine. Based 
on these figures, the total cost impact of the proposed AD on US 
operators is estimated to be $11,978,328.

Regulatory Impact

    This proposal does not have federalism implications, as defined in 
Executive Order 13132, because it would 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. Accordingly, 
the FAA has not consulted with state authorities prior to publication 
of this proposal.

[[Page 26154]]

    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 U.S.C. 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. 99-NE-29-AD.

    Applicability: Pratt & Whitney (PW) Models JT8D-1, -1A, -1B, -7, 
-7A, -7B, -9, -9A, -11, -15, -15A turbofan engines, installed on but 
not limited to Boeing 727 and 737 series, and McDonnell Douglas DC-9 
series airplanes.

    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 (e) 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 loss of engine throttle control, uncommanded 
acceleration, uncommanded deceleration or inflight shutdown, which 
could result in reduced airplane control during a critical phase of 
flight, accomplish the following:

Initial Inspection

    (a) At the next accessibility of the main fuel pump after 
accumulating 1,000 hours time in service (TIS) since last fuel pump 
overhaul, inspect, and replace, if necessary, the main fuel pump 
control shaft in accordance with procedures described in the 
Accomplishment Instructions of PW Alert Service Bulletin (ASB) 
A6381, dated March 15, 2000.

Repetitive Inspections

    (b) Thereafter, reinspect the main fuel pump control shaft and 
remove and replace, if necessary, in accordance with intervals and 
procedures described in the Accomplishment Instructions of PW ASB 
A6381, dated March 15, 2000.

Installation and Terminating Action

    (c) At the next main fuel pump overhaul, but prior to 
accumulating either 12,000 hours TIS since last fuel pump overhaul 
or 2,000 hours TIS after the effective date of this AD, whichever 
occurs later, install a reworked impeller, impeller gear train plate 
assembly and impeller cover assembly and a new main fuel pump 
control shaft in accordance with paragraph 2.A and 2.B. of PW ASB 
A6381, dated March 15, 2000. Installation of a reworked impeller, 
impeller gear train plate assembly and impeller cover assembly and a 
new main fuel pump control shaft in accordance with this paragraph 
constitute terminating action to the inspections required by 
paragraphs (a) and (b) of this AD.

Definitions

    (d) For the purpose of this AD:
    (1) Accessibility of the main fuel pump is defined as removal of 
the fuel control from the fuel pump or removal of the fuel pump from 
the engine.
    (2) Main fuel pump overhaul is defined as compliance with the 
manufacturer's recommended overhaul procedures described in Argo-
Tech Overhaul Manual 73-11-1.

Alternative Methods of Compliance

    (e) 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 (ECO). 
Operators shall submit their request through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the ECO.

Ferry Flights

    (f) 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 airplane to a location where 
the requirements of this AD can be accomplished.

    Issued in Burlington, Massachusetts, on May 1, 2000.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 00-11303 Filed 5-4-00; 8:45 am]
BILLING CODE 4910-13-P