[Federal Register Volume 62, Number 147 (Thursday, July 31, 1997)]
[Proposed Rules]
[Pages 40985-40987]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20193]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-ANE-13]
RIN 2120-AA64


Airworthiness Directives; AlliedSignal Inc. TPE331 Series 
Turboprop and TSE331 Turboshaft 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 AlliedSignal Inc., (formerly 
Garrett Engine Division, Garrett Turbine Engine Company and AiResearch 
Manufacturing Company of Arizona) TPE331 series turboprop and TSE331 
turboshaft engines. This proposal would require replacement or 
radiographic inspection, and replacement , if necessary, of certain 
third stage turbine stators with serviceable parts. This proposal is 
prompted by a report of an outer band weld that cracked subsequent to a 
radiographic inspection required by a previous AD. The actions 
specified by the proposed AD are intended to prevent third stage 
turbine wheel separation due to thermal fatigue cracking and shifting 
of the third stage turbine stator, which could contact the third stage 
turbine wheel and result in an uncontained engine failure and damage to 
the aircraft.

DATES: Comments must be received by September 29, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), New England Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 97-ANE-13, 12 New England 
Executive Park, Burlington, MA 01803-5299. Comments may also be sent 
via the Internet using the following address: ``9-ad-
[email protected]''. Comments sent via the Internet must contain 
the docket number in the subject line. Comments may be inspected at 
this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, 
except Federal holidays.
    The service information on AlliedSignal Service Bulletin No. 
TPE331-A72-0861, Revision 2, dated April 23, 1997, referenced in the 
proposed rule may be obtained from AlliedSignal Aerospace, Attn: Data 
Distribution, M/S 64-3/2101-201, P.O. Box 29003, Phoenix, AZ 85038-
9003; telephone (602) 365-2493, fax (602) 365-5577. The service 
information on National Flight Services Service Bulletin No. NF-TPE331-
A72-10961, dated April 28, 1997, referenced in the proposed rule may be 
obtained from either National Flight Services, Inc. 10971 E. Airport 
Services Road, Toledo Express Airport, Swanton, OH 43558; telephone 
(419) 865-2311, fax (419) 867-4224, or http://www.natfs.com, or 
National Flight Services of Arizona, Inc., 5170 W. Bethany Home Road, 
Glendale, AZ 85301; telephone (602) 931-1143, fax (602) 931-7264. 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: Joseph Costa, Aerospace Engineer, Los 
Angeles Aircraft Certification Office, FAA, Transport Airplane 
Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; telephone 
(562) 627-5246; fax (562) 627-5210.

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 97-ANE-13.'' 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. 97-aNE-13, 12 New England Executive Park, 
Burlington, MA 01803-5299.

Discussion

    The Federal Aviation Administration (FAA) has received a report of 
a third stage turbine stator outer band weld that cracked on an 
AlliedSignal Inc. Model TPE331-5 turboprop engine. This weld, removed 
from service in January 1996 after the crack was discovered during 
turbine maintenance, had passed a one-time radiographic inspection for 
unacceptable weld penetration and thermal fatigue cracking required by 
AD 87-19-02. While AD 87-19-02 was

[[Page 40986]]

superseded by AD 93-05-09, the requirement for a one-time radiographic 
inspection of the outer band weld for cracks was carried forward in to 
AD 93-05-09. The FAA determined that cracking initiated due to 
inadequate outer band butt weld penetration between the outer sheet 
metal ring and the nozzle casting. The FAA also determined that some 
radiographic films of unacceptable outer band welds may possibly have 
been misread by AlliedSignal Inc. In addition, numerous radiographic 
films are no longer on file at AlliedSignal Inc., and therefore 
reexamination of radiographic films of other welds is impossible. 
AlliedSignal Inc. no longer reads radiographic films; operators may use 
radiographic inspection in accordance with this AD as an alternate 
method of compliance with the radiographic inspection requirement of 
paragraph (h) of AD 93-05-09. Inadequate weld penetration could lead to 
fatigue cracking, shifting aft, and third stage turbine stator contact 
with the third stage turbine rotor. This condition, if not corrected, 
could result in third stage turbine wheel separation, which could 
result in an uncontained engine failure and damage to the aircraft.
    The FAA has reviewed and approved the technical contents of 
National Flight Services Service Bulletin (SB) No. NF-TPE331-A72-10961, 
dated April 28, 1997, that provides a list by serial number of third 
stage turbine stators not affected by this AD and describes procedures 
for the reinspection for unacceptable weld penetration and thermal 
fatigue cracking in third stage turbine stators initially inspected by 
AlliedSignal Inc.; and AlliedSignal Inc. SB No. TPE331-A72-0861, 
Revision 2, dated April 23, 1997, that describes procedures for 
replacing affected third stage turbine stators with redesigned 
serviceable stators.
    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 replacement of certain third stage turbine 
stators or radiographic inspection, and replacement, if necessary, with 
serviceable parts. The actions would be required to be accomplished in 
accordance with the SBs described previously.
    There are approximately 1,000 engines of the affected design in the 
worldwide fleet. The FAA estimates that 700 engines installed on 
aircraft of U.S. registry would be affected by this proposed AD. The 
FAA estimates that 210 engines would require unscheduled replacement, 
that it would take approximately 40 work hours per engine to accomplish 
the proposed actions, and that the average labor rate is $60 per work 
hour. Required parts would cost approximately $6,500 per engine. 
Approximately 350 engines would require replacement during hot section 
inspection, which would take approximately 2 work hours per engine, 
with a parts cost of $6,500. Approximately 14 engines would require 
unscheduled inspection, which would take approximately 50 work hours to 
accomplish, with a parts cost of $1,500. Approximately 21 engines would 
require inspection during hot section inspection, which would take 
approximately 10 work hours to accomplish, with zero parts cost. 
Approximately 35 engines would require unscheduled inspection and 
replacement, which would take approximately 50 work hours to 
accomplish, with a $6,500 parts cost. Approximately 70 engines would 
require inspection and replacement during hot section inspection, which 
would take approximately 10 work hours to accomplish, with a $5,000 
parts cost. The FAA has been informed by AlliedSignal Inc. that they 
will provide a redesigned third stage turbine stator assembly at a 
special program price and will pay for the labor to install this 
assembly. Based on these figures, without the special price program 
from the manufacturer, the total cost impact of the proposed AD on U.S. 
operators is estimated to be $4,986,100.
    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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive: AlliedSignal Inc.: Docket No. 97-ANE-13.
    Applicability: AlliedSignal Inc., (formerly Garrett Engine 
Division, Garrett Turbine Engine Company and AiResearch 
Manufacturing Company of Arizona) Model TPE331-1, -2, -2UA, -3U, -
3UW, -5, -5A, -5AB, -5B, -6, and--6A turboprop and TSE331-3U 
turboshaft engines with third stage turbine stators, Part Number (P/
N) 868379-3, except those engines with turbine stators listed by 
Serial Number (S/N) in Table 1 of the National Flight Services 
Service Bulletin (SB) No. NF-TPE331-A72-10961, dated April 28, 1997. 
These engines are installed on but not limited to: Mitsubishi MU-2B 
series (MU-2 series); Construcciones Aeronauticas, S.A. (CASA) C-212 
series; Fairchild SA226 series (Swearingen Merlin and Metro series); 
Prop-Jets, Inc. Model 400; Twin Commander 680 and 690 (Jetprop 
Commander); Rockwell Commander S-2R; Shorts Brothers and Harland, 
Ltd. SC7 (Skyvan); Dornier 228 series; Beech 18 and 45 series and 
Models JRB-6, 3N, 3NM, 3TM, and B100; Pilatus PC-6 series (Fairchild 
Porter and Peacemaker); De Havilland DH 104 series 7AXC (Dove); 
Ayres S-2R series; Grumman American G-164 series; and Schweizer G-
164 series airplanes; and Sikorsky S-55 series (Helitec Corp. S55T) 
helicopters.

    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 (g) 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 third stage turbine wheel separation due to fatigue 
cracking and

[[Page 40987]]

shifting of the third stage turbine stator, which could result in an 
uncontained engine failure and damage to the aircraft, accomplish 
the following:
    (a) For engines with third stage turbine stators with S/Ns 
listed in Table 1 of National Flight Services SB No. NF-TPE331-A72-
10961, dated April 28, 1997, no action is required.
    (b) For engines with third stage turbine stators with S/Ns not 
listed in Table 1 of National Flight Services SB No. NF-TPE331-A72-
10961, dated April 28, 1997, remove the unserviceable third stage 
turbine stator assembly in accordance with the applicable engine 
maintenance manual and the following schedule:

------------------------------------------------------------------------
   Third stage turbine stator cycles in                                 
     service (cis) since radiographic                                   
 inspection in accordance with AD 87-19-02        Removal schedule      
paragraph (b) or AD 93-05-09 paragraph (h)                              
------------------------------------------------------------------------
Unknown CIS since inspection..............  Remove within 600 CIS after 
                                             the effective date of this 
                                             AD, at next access, or     
                                             prior to March 31, 2002,   
                                             whichever occurs first.    
2200 or more CIS since inspection.........  Remove within 600 CIS after 
                                             the effective date of this 
                                             AD, at next access, or     
                                             prior to March 31, 2002,   
                                             whichever occurs first.    
Less than 2200 CIS since inspection.......  Remove prior to accumulating
                                             2,800 CIS, at next access, 
                                             or prior to March 31, 2002,
                                             whichever occurs first.    
------------------------------------------------------------------------

    (c) For the purpose of this AD, the next access to the third 
stage stator assembly is defined as disassembly of the turbine 
beyond the removal of the third stage rotor.

    Note 2: This AD does not supersede AD 93-05-09. The removal 
schedule in paragraph (b) of this AD does not affect the 
requirements of AD 93-05-09.
    (d) For the purpose of determining third stage turbine stator 
removal under paragraph (b) of this AD, third stage turbine stator 
hours time in service (TIS) may be converted to CIS since inspection 
by multiplying by 1.5 the number of hours since radiographic 
inspection in accordance with paragraph (b) of AD 87-19-02 or 
paragraph (h) of AD 93-05-09.
    (e) For third stage turbine stator assemblies removed in 
accordance with paragraph (b) of this AD, accomplish either a 
radiographic inspection for inadequate weld penetration and fatigue 
cracking, and, if necessary, replace with a serviceable assembly in 
accordance with the Accomplishment Instructions of National Flight 
Services SB No. NF-TPE331-A72-10961, dated April 28, 1997; or 
replace with a serviceable assembly in accordance with the 
Accomplishment Instructions of AlliedSignal Inc. SB No. TPE331-A72-
0861, Revision 2, dated April 23, 1997. Accomplishing the 
radiographic inspection required by this paragraph constitutes 
compliance with the radiographic inspection requirement of paragraph 
(h) of AD 93-05-09.
    (f) 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, Los Angeles Aircraft Certification 
Office. Operators shall submit their requests through an appropriate 
FAA Principal Maintenance Inspector, who may add comments and then 
send it to the Manager, Los Angeles Aircraft Certification Office.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the Los Angeles Aircraft Certification 
Office.

    (g) 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 July 8, 1997.
Ronald L. Vavruska,
Acting Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 97-20193 Filed 7-30-97; 8:45 am]
BILLING CODE 4910-13-U