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LIST OF ILLUSTRATIONS ..........vii
LIST OF TABLES ..........viii
LIST OF ACRONYMS ..........ix
EXECUTIVE SUMMARY .......... xi

Background and Purpose .......... xi
Current Engine Experience and Performance .......... xii
Findings .......... xiii
Engine Improvement Program .......... xiii
Re-engining with the T800 .......... xiv
Re-engining with Other Than the T800 .......... xv

Recommendations .......... xvi

1 - INTRODUCTION ..........1

1.1 BACKGROUND .......... 1
1.1.1 Re-Engine Economic Analysis for the HH-65A .......... 1
1.1.2 T800/HH-65A Proof of Concept .......... 3
1.1.3 DOT OIG Audits ..........4

1.2 PURPOSE OF THE TSC ANALYSIS .............. 5
1.3 APPROACH ................................. 5

2.1 LTS 101 ENGINE DESCRIPTION .......... 7
2.2 AIRCRAFT AVAILABILITY .......... 8
2.2.1 History .......... 8
2.2.2 Maintainability Goals and Performance .......... 9
2.2.3 Spare Parts Supply .......... 11

2.3 ENGINE MAINTENANCE COSTS .......... 12
2.3.1 Capital Costs .......... 12
2.3.2 Depot Maintenance Costs .......... 13
2.3.3 Field Maintenance Costs .......... 15

2.4 OPERATIONAL CONSIDERATIONS .......... 16
2.4.1 Foreign Object Damage .......... 16
2.4.2 One-Engine Hover .......... 16
2.4.3 Mission Growth Potential .......... 16

3.1 PROPOSED SOLUTIONS FOR LTS 101 PROBLEMS .......... 19
3.1.1 PT Wheel Cracks .......... 19
3.1.2 GP Turbine Blade Unwrap and Blade Tip Separation .......... 20
3.1.3 Axial Compressor Blade Damage .......... 20
3.1.4 GP Nozzle Heat Erosion ......................... 21
3.1.5 Oil Coking .......... 21
3.1.6 Summary of Major Component Problems and Solutions .......... 22

3.2 TECHNICAL RISK .......... 22 (Page vi)
3.3 SCHEDULES .......... 23
3.4 COSTS .......... 24
3.5 IMPACTS ON AIRCRAFT AVAILABILITY .......... 25
3.6 RECOMMENDATIONS .......... 27

4.1 BACKGROUND .......... 29
4.1.2 T800 .......... 30

4.2 HH-65A/T800 PROOF OF CONCEPT .......... 31
4.3 TECHNICAL RISK ASSESSMENT ........ 32
4.4 POTENTIAL RE-ENGINING SCHEDULES .......... 32
4.5 COSTS ........ 34
4.5.1 Development, Test, and Certification/Qualification Costs .......... 34
4.5.2 Cost of Engines .......... 35
4.5.3 Aircraft Modification and Engine Installation Costs .......... 36
4.5.4 Operations and Support Costs .......... 36
4.5.5 Summary of Costs .......... 36

4.6 OTHER ISSUES .......... 38
4.6.1 Reliability and Maintainability .......... 38
4.6.2 Safety .......... 38
4.6.3 Mission Impacts .......... 39

4.7 RECOMMENDATIONS .......... 40

5.1 OVERVIEW OF THE MARKET .......... 41
5.2 POTENTIAL SCHEDULES .......... 42
5.3 POTENTIAL COSTS .......... 44
5.4 RECOMMENDATIONS .......... 45

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List Of Illustrations

FIGURE 01 - LTS 101 Engine Schematic ......................... 07
FIGURE 02 - Fleet Availability History (hrs) ................. 09
FIGURE 03 - Fleet Availability History (%) ................... 09
FIGURE 04 - Availability History at Air Station Savannah ..... 10
FIGURE 05 - Current Engine Maintenance Cost Breakdown ........ 14
FIGURE 06 - LTS 101 Maintenance Costs per Engine Hour ........ 25
FIGURE 07 - Engine Improvement Cost Impacts .................. 25
FIGURE 8a - MTBF Trend ....................................... 26
FIGURE 8b - Availability Trend ............................... 26
FIGURE 09 - Relating Availability to Mean Time to Failure .... 26
FIGURE 10 - T800 Re-Engining Schedules ....................... 33
FIGURE 11 - Cost Comparison of LTS-101 and T800 .............. 37
FIGURE 12 - Re-Engining Schedule for Other Than T800 ......... 43
FIGURE 13 - Cost Comparison of All Options ................... 44

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EXECUTIVE SUMMARY

BACKGROUND AND PURPOSE

The U.S. Coast Guard (USCG) maintains and operates a fleet of 96 HH-65A ("Dolphin") Short Range Recovery helicopters. These aircraft were built by Aerospatiale Helicopter Corporation (AHC), and each is equipped with two LTS 101750B-2 engines built by Textron Lycoming Corporation. They were delivered to the Coast Guard between February 1985 and April 1989, and replaced the USCG's HH52A fleet. The fleet is used primarily for search and rescue (SAR), but also for drug interdiction and other law enforcement activities. The SAR mission dictates that one or more aircraft at each air station must be available to fly (airborne within 30 minutes of notification) on a 24-hour basis.

Extensive problems have been experienced with engine reliability and maintainability, and these problems have had serious adverse impacts on costs and aircraft availability. The USCG has been addressing these problems in two ways.

• Improve the existing LTS 101 engines -- The USCG is working on improvements both in-house and in conjunction with Textron Lycoming. Some improvements have been made, and other s are in process, although significant problems remain.

• Examine the feasibility of re-engining -- Options being explored include: the T800 engine being developed for the U.S. Army; and other candidate engines.

On September 17, 1987, the USCG tasked AHC to perform an economic analysis of re-engine candidates for the HH-65A. The purpose of the study was to determine the economic feasibility of re-engining the HH-65A fleet, not to select the best engine. The study was completed in April 1988 and updated by the USCG in October 1988. Based partly on the results of this economic analysis, the USCG recommended proceeding with a "Proof of Concept" effort to demonstr ate the feasibility of re-engining the HH-65A with the T800.

The DOT Office of Inspector General (OIG) has undertaken several audits related to the HH-65A fleet. Based on its analyses, the OIG was concerned that the LTS 101 improvement program might not succeed, and that there was a risk that without adequate contingency plans the USCG might not have sufficient aircraft available to perform its mission; furthermore, the OIG questioned whether the T800

(Page xii)

would be the best way to fix the Dolphin engine problems in the least amount of time and for the lowest life cycle cost.

In light of different views regarding likely costs, schedules, and technical risks associated with the LTS 101 improvement program and with the T800 and other reengine candidates, the Research and Special Programs Administration's Transportation Systems Center (RSPA/TSC) was asked by the Assistant Secretary for Administration to undertake an independent assessment. This assessment was to cover current engine problems and the engine improvement program, potential re-engining with the T800, and other potential re-engine candidates.

The intent was to examine some of the key issues and variables involved, and the risks associated with proceeding with the various possible courses of action. Interviews were held with USCG managers and staff at headquarters, at the Aircraft Repair & Supply Center (AR&SC), and at the air stations in New Orleans and Savannah. Interviews also were held with officials and staff members of the Office of Inspector General, Textron Lycoming Corporation, the U.S. Army Aviation Systems Command (AVSCOM), and the FAA Engine Certification Office. Additional information was obtained from telephone conversations with these and other organizations, and from reports and other documents provided by the USCG and others. The extent of information and the diversity of views provided by the large number of people who were contacted were extremely helpful in conducting this study.

The assessment was conducted "in-house" over a period of 10 weeks by RSPA/TSC technical personnel with engine expertise provided by Professor Jack Kerrebrock of the Massachusetts Institute of Technology. The RSPA/TSC study team accepts full responsibility for the f~ndings and conclusions presented in this report.

CURRENT ENGINE EXPERIENCE AND PERFORMANCE

The USCG's LTS 101 engine reliability and maintainability problems have had significant adverse impacts on both costs and aircraft availability. There also are certain operational issues related to the current engine. Some key indicators are listed below.

• The USCG has not been able to meet its aircraft availability goal of 71%, due primarily to premature failure of critical engine parts and to problems with spare parts supply. During the past two year, availability has ranged between about 53% and 62%.

  (Page xiii)

• The USCG has had to take engines out of service for maintenance far more frequently than was expected. The expected cycle for depot overhaul was 2400 engine-hours. Actual engine mean time to depot was 255 engine-hours between July 1988 and February 1989, improving to about 400 engine-hours during April-August 1989.

• Depot engine maintenance costs, while improving, still are averaging about $142 per engine-hour, compared with an anticipated maintenance cost of about $40 per hour.

• About 88% of these maintenance costs have been for parts repair and replacement, of which over 72% was for only four components: power turbine rotor; gas producer rotor/blades; gas producer nozzle; and axial compressor.

• The aircraft is operating at or near its maximum gross weight, and there has been a trend towards increased weight resulting from an expanding USCG HH-65A mission. The LTS 101 engine provides very limited potential for accommodating mission growth.

• Because of potential foreign object damage to the axial compressor, the HH-65A is restricted from hovering or landing in sandy or similar abrasive environments except for urgent operational missions. A particle separator to alleviate this problem cannot be installed because of insufficient spare engine power.

• The HH-65A with the current engine cannot hover on a single engine. In almost all situations, if an engine is lost while hovering, the aircraft will go down.

FINDINGS

Engine Improvement Program

Textron Lycoming has acknowledged the reliability and maintainability problems with the LTS 101 engine, and has been developing improved component designs and manufacturing processes. A few improvements already are being retrofitted into the USCG's fleet (e.g., wrought axial compressors), and others are in the development process. The improvement program is intended to reduce premature component failures and unscheduled engine removals, and to reduce maintenance costs.

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The technical risks associated with the LTS 101 improvement program are judged to be low. The improvements use available technologies, and similar component designs have been used elsewhere.

There are indications of serious management commitment by Lycoming with regard to improving the reliability and maintainability of the LTS 101. For example, a new Lycoming-developed rebladeable power turbine wheel was recently approved by the FAA.

A reasonably successful engine improvement program would enable the USCG to meet its 71% aircraft availability goal.

The cumulative 10% discounted cost for the engine improvement program over the period 1989 to 2005 is estimated at between $69 and $90 million (in 1989 dollars), versus $114 million for continued use of the engine with no improvements.

Re-engining with the T800

The T800 is an advanced technology engine being developed for the U.S. Army's Light Helicopter Program (LHX). It is a significantly more powerful engine than the LTS 101 (approximately 1200 versus 700 shaft horsepower). Initial delivery of T800 engines to the Army is not expected until June 1995, but the manufactur er anticipates FAA certification in early 1991 and production capability by ear ly 1992 for a commercial market. A Phase 1 "Proof of Concept" program will begin shor tly, in which two preliminary flight rated T800 engines will be installed and test flown in one of the USCG's Dolphins; the intent is to demonstrate the feasibility of retrofitting the HH-65A with the T800.

• The T800 engine is judged to have low technical risk. It has its roots in engine development programs begun in the late 1970s by the Army and Air Force. The T800 has been under development since 1985, and has an excellent record to date of meeting performance and schedule milestones. It has been test flown in an Agusta 129 helicopter, and other installations and flight tests are being planned.

• T800 production capability would not be in the critical path of a USCG re-engining program. Planned production schedules of the manufacturer -- the Light Helicopter Turbine Engine Company, or LHTEC -- would accommodate the earliest expected order for USCG engines.

  (Page xv)

• Delivery of initial production engines for the USCG likely would occur between year end 1993 and year end 1995, with re-engining of the fleet completed between late 1996 and year end 1999.

• About 45-60% of the T800 life would remain at the end of the present airframe life in 2005. The engines at that time could be sold to the Army or installed on the USCG's next generation of Short Range Recovery helicopters.

• Relative to the LTS 101, the T800 would offer significantly better reliability and maintainability due to DOD logistic support and to the engine's expected durability, ease of maintenance, and operation by the USCG at a low fraction of available power.

• The T800 would provide better safety by permitting the HH-65A to hover on one engine.

• The T800 would permit removal of the operating restriction currently on the HH-65A because of potential foreign object damage.

• Re-engining the HH-65A with the T800 would add about 50 pounds to the aircraft, but would also provide the potential for accommodating mission growth. The greater power of the T800 offers potential for increasing the maximum gross weight of the aircraft, although this would require other structural and dynamic system changes.

• The cumulative 10% discounted cost of proceeding with the engine improvement program followed by re-engining with the T800 is estimated to be $150 million in 1989 dollars.

Re-engining with Other Than the T800

• Based on a very preliminary survey, it is not certain that there are any production engines that meet all USCG requirements. Certificated engines in the power range tend to be heavier than the LTS 101 or less fuel efficient than the T800. The Turbomeca "Arriel 1" series engines may be the most promising in terms of providing a suitable, relatively low-cost, easy-retrofit re-engine candidate.

• The cost of re-engining with an easy-retrofit engine in the LTS 101 power range (say, a Turbomeca Arriel 1G or 1S) would be lower than reengining (Page xvi) with the T800, but higher than the cost associated with a successful LTS 101 improvement program.

• Other engines do not offer significant schedule advantages over the T800. Under the most optimistic scenario based on emergency acquisition conditions, the earliest delivery of engines would be about July 1993, which is only about 6 months earlier than the most optimistic date for initial delivery of T800 engines.

• Identification of another suitable engine for the HH-65A represents a contingency or insurance option to guard against the possibility that problems will occur with both the LTS 101 improvement program and the T800 program.

RECOMMENDATIONS

(1) Continue with the LTS 101 engine improvement program. Defer a decision on one of the improved components (a new rear bearing support housing designed to alleviate oil coking problems) until more information is available on the effectiveness of less expensive interim improvements.
(2) Establish a program to closely monitor implementation and results of the LTS 101 improvement program.
(3) Conduct an independent technical audit of the designs of the new parts provided by Lycoming, possibly through the Air Force facility at Wright Patterson AFB in Ohio.
(4) Consider conducting durability tests on the redesigned LTS 101 components.
(5) Complete the Phase 1 Proof of Concept for the T800.
(6) Establish criteria and evaluation procedures now for the T800 re-engine declslon.
(7) Investigate airframe modifications that would be needed in conjunction with T800 re-engining to allow an increase in the HH-65A's maximum gross weight to accommodate mission growth.

(Page xvii)

(8) Conduct a more detailed near-term survey to identify other re-engine candidates.
(9) Consider proceeding with a development, test, and evaluation phase if a suitable re-engine candidate is identified.

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Background

The U.S. Coast Guard maintains and operates a fleet of 96 HH-65A ("Dolphin") Short Range Recovery (SRR) helicopters. These aircraft were built by Aerospatiale Helicopter Corporation (AHC) and each is equipped with two LTS 101750B-2 engines built by Textron Lycoming Corporation. They wer e delivered to the Coast Guard between February 1985 and April 1989, and replaced the USCG's HH52A fleet. The fleet is used primarily for search and rescue (SAR), but also for drug interdiction and other law enforcement activities. The SAR mission dictates that one or more aircraft at each air station (the number varies) must be available to fly (airborne within 30 minutes of notification) on a 24-hour basis.

Extensive problems have been experienced with regard to engine reliability and maintainability, and these problems have had serious adverse impacts on costs and aircraft availability. Some of these impacts can be inferred from the numbers and locations of aircraft and engines, as summarized in Table 1. The Coast Guard has had to obtain a very high number of spare engines -- slightly over one per aircraft. However, more than half of these are awaiting depot maintenance at the USCG's Aircraft Repair & Supply Center (AR&SC), and most air stations have no spare engines ready for installation.

The USCG has been addressing these problems from two perspectives.
(1) Improve the existing LTS 101 engines. The USCG is working on improvements both in-house and in conjunction with Textron Lycoming. Some improvements have been made, and others are in process, although significant problems remain.
(2) Examine the feasibility of re-engining. Options being explored include: the T800 engine being developed for the U.S. Army; and other candidate engines.

1.1.1 - Re-Engine Economic Analysis for the HH-65A

On September 17, 1987, the USCG tasked AHC to perform an economic analysis of re-engining candidates for the HH-65A. The purpose of this study was

(Page 2)

... Table 1 - Aircraft and Engine Locations As Of 09/28/89

to determine the economic feasibility of re-engining the HH-65A fleet, not to select a "best" engine. The study was completed in April 1988 (Footnote 1).

Two engines were examined representing a perceived range from low retrofit cost to high cost/high performance: the Turbomeca Arriel 1G and the T800, respectively. The Arriel 1G is a developmental engine, not a certificated or production engine, but was felt to be "...interchangeable with the Arriel 1C1 [already installed] in the Aerospatiale SA365N1 'Dauphin' (from which the HH-65A was basically derived)." Similarly, the T800 is not yet a certificated engine; it is being developed for the U.S. Army's Light Helicopter Program (LHX), and at the time of the AHC study, two contractor teams were developing competitive prototype engines.

AHC results. The study projected investment costs and operations and support (O&S) costs for the two alternative engines, and compared these with projected

(Page 3)

costs for the existing LTS 101-750B-2 engine assuming no improvement in its reliability and maintainability. Using a discount rate of 10 percent, the cumulative present values in 1988 dollars of all outlays from 1988 through 2004 were estimated as:

LTS 101 engined aircraft ......... $204.4 million
Arriel 1G engined aircraft ...... $206.6 million
T800 engined aircraft.............. $270.3 million

Thus, by a very slight margin, the lowest life cycle costs were associated with the existing LTS 101 engine. Analysis of the sensitivity of the cost estimates to changes in discount rate, schedules, overhaul cycle time, and O&S costs did not alter the relative rankings.

USCG update. Subsequent to completion of the AHC study and to the selection in October 1988 of a winner of the T800 competition, the USCG updated the AHC results (Footnote 2). This update incorporated more recent LTS 101 engine support cost experience, and more specific data for the selected version of the T800. (Cost estimates for the Arriel 1G were not changed.) The USCG's revised life cycle costs for the 1988-2004 period (1988 dollars, 10 percent discount rate) were:

LTS 101 engined aircraft ........ $283.88 million
Arriel 1G engined aircraft ....... $206.6 million
T800 engined aircraft .............. $281.36 million

The life cycle cost for the LTS 101 was higher than in the AHC study because the USCG found that the operating and support costs of the engine had risen since completion of the AHC study. Since T800 re-engining could not occur immediately, some of these increased costs also accrued to the T800 option, but this was balanced partly by a lower estimate of T800 engine purchase costs. No new information was available on the Arriel 1G, so the USCG did not alter the AHC estimate of life cycle cost for this option.

1.1.2 - T800/HH-65A Proof of Concept

Based on the need for a contingency plan, on perceived operational benefits of the T800, and on the results of the AHC economic analysis and subsequent USCG update, the USCG recommended proceeding with a "Proof of Concept" effort to

(Page 4)

demonstrate the feasibility of re-engining the HH-65A with the T800. The str ategy is viewed as a parallel effort to the LTS 101 reliability improvement program that will allow the USCG time to evaluate Lycoming's technical fixes. If the cost of ownership and reliability of the LTS 101 does not improve substantially, the USCG will be positioned to pursue a re-engine effort.(Footnote 3)

The Proof of Concept required a memorandum of understanding (MOW) with the Army, plus a request to Congress from the Secretary of Transportation to reprogram $10 million FY'89 AC&I funds. The Secretary concurred with the recommendation, the reprogramming request was sent to and approved by Congress, and an Army-USCG MOU was executed.

1.1.3 - DOT OIG Audits

The DOT Office of Inspector General has undertaken several audits related to the HH-65A fleet.

• Report No. AV-CG-4-014, dated March 16, 1984, was an audit of the SRR Helicopter Replacement Program.
• Report No. R6-CG-8-152, dated July 12, 1988, was an audit of aircraft maintenance at Air Station, New Orleans (which has five Dolphin helicopters).
• Report No. AV-CG-9-030, dated August 9, 1989, is a recent "Management Advisory Report on the Dolphin Helicopters' Performance."

Based on analysis being done for the last report, the OIG raised a number of issues and questions related to the possibility that the LTS 101 improvement program will not succeed, to the best way to reduce the risk that the USCG will not have sufficient aircraft available to operate its mission, and to the advisability of proceeding with the $10 million (then $10.5 million) reprogramming request for the HH-65A/T800 Phase 1 Proof of Concept. More specifically, issues were raised regarding T800 delivery schedules and costs, the future of the LHX program and its impact on the T800, and the scope and value to the Coast Guard of the Phase 1 Proof of Concept. (Footnote 4)

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1.2 - Purpose Of The TSC Analysis

In light of different views regarding likely costs, schedules, and technical risks associated with the LTS 101 engine improvement program and with the T800 and other re-engine candidates, the Research and Special Programs Administration's Transportation Systems Center (RSPA/TSC) was asked by the Assistant Secretary for Administration to undertake an independent assessment. This assessment was to cover current engine problems and the engine improvement program, potential re-engining with the T800, and other potential re-engine candidates.

The intent was not to re-do the detailed AHC life cycle cost analysis, but to provide a short-term assessment of some of the key issues and variables involved, and of the risks associated with proceeding with the various possible courses of action. TSC began work on July 26, 1989, and provided a series of three verbal briefings in Washington to various officials and members of OST, USCG, and OIG. Findings and recommendations were discussed at the final briefing on October 5, 1989, approximately 10 weeks from project start.

This report documents those f~ndings. It was delivered to OST in draft form on October 27, 1989. This f~nal version incorporates comments by OST, USCG, and OIG, as well as some more recent information on the HH-65A/T800 Phase 1 Proof of Concept.

1.3 - Approach

The approach was to first gather information pertaining to LTS 101 maintenance experience, to the LTS 101 improvement program, to the T800, and to other re-engine candidates. TSC then did an independent assessment of likely schedules, costs, technical risks, and mission impacts, compared the results of these assessments, and developed recommendations, as presented in the final briefing and in this report.

Sources of information included review of existing reports and other documentation, and visits and/or phone conversations with the various concerned parties. Organizations visited included:

• U.S. Coast Guard:
  • Headquarters (Washington, D.C.)
  • Aircraft Repair & Supply Center (AR&SC) (Elizabeth City, N.C.)
  • Air Stations (New Orleans, LA, & Savannah, GA)
  • Office of the DOT Inspector General (Washington, D.C.)

(Page 6)

• - Textron Lycoming Corporation (LTS 101 manufacturer)
• - U.S. Army Aviation Systems Command (AVSCOM), LHX Program Manager's Office (LHX PMO)
• - FAA Engine Certification Office

Additional telephone contacts were made with:

• - Light Helicopter Turbine Engine Company (LHTEC) (T800 manufacturer)
• - Societe Turbomeca (Arriel series engine manufacturer)
• - FAA Helicopter Certification Office

(Page 7)

2.1 - LTS 101 Engine Description

Each HH-65A helicopter is equipped with two Textron Lycoming LTS 101-750B-2 engines. This engine is a front drive turboshaft design, produces 658 maximum continuous shaft horsepower (shp), and has a life limit of 8500 hours.A simplified engine schematic is presented in Figure 1. The engine is comprised of the compressor, the combustion chamber, the gas producer, and the power turbine. Inlet air enters the compressor, whose function is to accelerate air flow and increase its pressure. Two separate stages, axial and centrifugal, comprise this section. The compressed air, mixed with fuel, is ignited in the combustion

... Figure 1 - LTS101 Engine Schematic

chamber. The high speed gases are directed into the gas producer (GP) section through a nozzle to turn the bladed GP rotor. The function of the GP section is to drive the compressor stages which are attached to the GP rotor shaft. Gases leaving the GP rotor are directed into the power turbine (PT) section. They are directed by the PT nozzle onto the PT rotor blades. The turning PT rotor shaft, which nests inside the GP rotor shaft, provides power to the helicopter via the engine gear box.

(Page 8)

Although the HH-65A helicopters have experienced both engine and air frame problems, this study is limited to an assessment of engine problems and options. The current LTS 101 engine has caused problems with aircraft availability. The high cost of engine maintenance has strained the budget. Also, issues related to operational capability have been raised.

2.2 - Aircraft Availability

Availability is the number of hours the average fleet aircraft is in a missioncapable status, usually expressed as a percent of total hours. The Coast Guard has set 71 percent as its availability goal. Premature failure of critical engine parts and problems with spare parts supply has made the engine the pacing factor precluding the Coast Guard from achieving its availability goal. There appears to be no clear trend toward meeting the availability goal. As the gap between the goal and actual availability widens, it becomes increasingly difficult for the Coast Guard to perform its mission.

2.2.1 - History

The impact of engine problems on Coast Guard activities can be measured through fleet availability. It is calculated from USCG data describing aircraft "nonmission-capable" status. Figure 2 displays a history of fleet availability. The rise in total fleet hours shows how the fleet has been phased in over the time period. With delivery of the final helicopter earlier this year, total annual fleet hours should remain near current levels. The graph shows a significant gap between the 71 percent goal and the actual availability. The goal has never been achieved on an overall fleet basis.

Figure 3 shows the same data as a percent of time the fleet is available, or mission-capable. Time in unavailable status is shown by two possible reasons: supply, and maintenance.(Footnote 05) When setting the maximum non-mission-capable goal to 29 percent, the Coast Guard allowed 24 percent for maintenance and 5 percent for supply. However, Figure 3 shows that "non-mission-capable - supply" time has been a much higher proportion of the total. If the maintenance situation wer e unchanged but there were a large improvement in parts supply (such that "non-mission-capable supply" time was near the targeted 5%), the availability would be near or at the 71% goal.

(Page 9)

... Figure 2 - Fleet Availability History (hrs)

... Figure 3 - Fleet Availability History (%)

2.2.2 - Maintainability Goals and Performance

One measure of engine maintainability is mean time between overhauls (MTBO) which, for the Coast Guard, is approximately equivalent to mean time to

(Page 10)

depot (MTTD). The expected MTBO for this Lycoming engine was 2,400 hours. In a Coast Guard study using eight months of data from July 1988 through February 1989, the MTTD was calculated to be 255 engine-hours.(Footnote 06) A TSC examination of data from the USCG's Aircraft Computerized Maintenance System (ACMS) confirmed this number and also calculated the MTTD as 400 hours for the more recent period of April 1989 through August 1989.

Since parts availability is a contributing factor, it is difficult to explain this recent increase in MTTD from a direct examination of aircraft availability data. Discussions with air station personnel and examination of ACMS data suggest the possibility of a "learning curve" effect, for at least some air stations. That is, as air stations gather more experience in maintaining the engine, the probability that an

... Figure 4 - Availability History At Air Station Savannah

engine will be sent to depot before its scheduled time decreases slightly. Thus, availability improves slightly. As shown in Figure 4, for example, Air Station Savannah displays this tendency.

In any case, the MTTD is well below the expected value and has resulted in decreased aircraft availability and a strain on limited resources available to keep the aircraft flying. The initial interval of engine removal for inspection was set at 600 engine-hours. To assure the flying integrity of the engine, the Coast Guard now inspects the engine at 60 engine-hour intervals (although these inspections do not always entail engine removal).

(Page 11)

The Coast Guard has been plagued with high component replacement rates on the LTS 101 engine. An examination of USCG data on individual engine component performance is given in Table 2 as the mean time to removal contrasted with the design life. Removal can be for the purpose of inspection, repair, or replacement. The last column shows the percentage of the expected life which has actually been

... Table 2 - Mean Time Between Removal (MTBR) Compared To Expected Component Life

experienced.

2.2.3 - Spare Parts Supply

Discussions with USCG personnel at Headquarters, at the Aircraft Repair and Supply Center (AR&SC), and at rcprcsentative air stations all support the notion that the maintainability problems are exacerbated by extreme difficulties in spare parts supply. At the air stations, the ability to maintain aircraft availability is hampered by the lack of spare engines and engine parts. At the depot (AR&SC), the lack of spare parts has restricted engine overhaul production and has resulted, in extreme cases, in aircraft on ground (AOG) status.

Recent discussions with depot personnel (Footnote 7) (AR&SC) have shown how the lack of an adequate parts supply has affected aircraft maintainability and availability. Capacity exists at the AR&SC to overhaul 7 to 12 engines per week. AR&SC staff

(Page 12)

estimate that an overhaul rate of 5 to 7 engines per week is needed to adequately resupply the air stations with engines. Due to the lack of spare parts inventories, AR&SC was overhauling only 2 to 3 engines per week at the time of the TSC visit, and there were six aircraft in AOG (aircraft on ground) status.

The result has been the inability to conduct a planned maintenance operation. Rather, much of the activity, by necessity, is reactive and extremely inefficient. Engines and parts are cannibalized from other aircraft. This changes a single r epair into several: one to service the original aircraft; another to restore the cannibalized aircraft; and possibly a third to repair components damaged in the process of moving parts from one aircraft to another.

A review of AR&SC-provided documentation related to spare par ts procurement supports this notion. One example concerns an order for 95 GP nozzle assemblies. The original contract for these parts called for a September 1987 delivery. An extended delivery date of January 1988 was later negotiated. As of June 1989, 58 of the units remained undelivered.

2.3 - Engine Maintenance Costs

Engine costs analyzed in this study included capital costs and depot related costs, but not field maintenance costs. The nature of USCG operations makes field maintenance difficult to measure. Field maintenance is performed by uniformed USCG personnel who perform maintenance and other duties as required. Poor reliability and maintainability experience also results in increased labor for management, procurement, and other administrative functions, which also are performed by uniformed personnel with collateral duties. In addition, overtime by uniformed personnel does not result in additional monetary expenditures, but does affect morale and represents time that could be spent on other activities.

2.3.1 - Capital Costs

Capital costs relate primarily to the examination of improvement and replacement options. Capital costs for the current engine are consider ed sunk costs; i.e., under any option, these funds have already been spent. There is presumed to be no salvage value left to the current LTS 101 engine at the end of the airframe life. Costs for any engine improvements are considered capital costs.

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2.3.2 - Depot Maintenance Costs (USCG's)

Current depot costs per overhaul were estimated as:
- parts .............................................	$49,920
- depot labor ........................................	$3,210
- transportation .....................................	$2,000
- fixed plant ........................................	$1,885
TOTAL PER OVERHAUL ...................................	$57,015

... Table 3 - Bill Of Materials For LTS101 Engine Overhaul

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Parts, labor, and fixed plant costs were derived from a USCG study of costs incurred between July 1988 and February 1989.(Footnote 09) Parts repair and replacement costs are listed in Table 3, which shows that nearly half these costs are accounted for by only two parts -- the power turbine rotor and the gas producer rotor. A fixed annual cost of $492,000 for plant and equipment was allocated on a per overhaul basis. The number of overhauls was based on an MTTD of 400 engine-hours. An average cost of $2,000 for two-way transportation for depot maintenance was added based on verbal information supplied by the USCG.

These costs translate to about $142 per engine-hour and $14.9 million per year, assuming 630 annual flight hours per aircraft. A percentage breakdown of these costs is shown in Figure 5. The shaded areas represent about 60 percent of total costs, and are for only four engine components. These components are the focus of the engine improvement program, and are discussed in Chapter 3.

... Figure 5 - Current Engine Maintenance Cost Breakdown

To provide some perspective for assessing the USCG's LTS 101 maintenance costs, some costs for selected other, non-USCG helicopter engines are shown in Table 4. Although these other costs are significantly lower than the USCG's current experience, there are some important differences between USCG and normal commercial operations that contribute to a higher cost of operation for the USCG:

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operation of a heavier aircraft (relative to the power range of the engine) to satisfy more stringent mission requirements which necessitate, for example, a rescue swimmer and extensive rescue and communications equipment; operation of the aircraft in a more severe environment (rescues in severe weather and over the water); and operation of a more severe mission profile (rescue operations rely heavily upon hovering, which is more taxing to the aircraft and engines).

2.3.3 - Field Maintenance Costs

... Table 4 - Helicopter Engine Maintenance Cost Comparisons

As noted earlier, it is difficult to isolate the cost of USCG field maintenance for the LTS 101. Uniformed field maintenance personnel are paid a constant salary, regardless of the number of hours worked. They are also assigned collateral duties; maintenance staff also serve as flight crew members. Also, it is diffrcult to predict how the level of field maintenance activity would change under the various engine improvement and replacement options. For these reasons, field maintenance costs were not considered as part of the baseline costs of the current engine.

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2.4 - Operational Considerations

In addition to problems with availability and cost, there are some operational issues associated with the LTS. They include a problem with foreign object damage, the inability to hover on a single engine, and the lack of mission growth potential.

2.4.1 - Foreign Object Damage

As shown earlier in Figure 1, outside air entering the engine first flows onto the axial compressor. This air flow may contain small particles, such as sand and debris, which can nick or erode the axial compressor blades. Although there is a screen of about one quarter inch mesh in the air flow path, this is insufficient to remove the finer particles. A device to remove the debris, such as a particle separator, cannot be employed because there is insuffrcient spare engine horsepower to drive the device. As a result, there is an operating restriction on the HH-65A that limits "hovering/landing in sandy or similar abrasive environments...to urgent operational missions." (Footnote 9) No engine improvement program has been proposed for the LTS 101 that will correct this situation.

2.4.2 - One-Engine Hover

Due to lack of extra engine horsepower, the HH-65A helicopter is unable to hover on a single engine. The aircraft can fly on a single engine, but requires either a 40 knot wind or at least 200 feet of altitude to fly out of a hover on one engine. Most rescue operations occur at about 50 feet, however. Thus, if an engine fails during the hovering portion of a rescue operation, the aircraft will go down.

2.4.3 - Mission Growth Potential

The USCG aircraft mission is continually being revised, which usually translates into additional weight on the aircraft. Recent additions include secure communications equipment, devices to assist with shipboard landing, and a Congressionally-mandated rescue swimmer.

The aircraft already is operating at or near its maximum gross weight (MOW) of 8,900 pounds. The USCG indicates that the MGW can grow relatively easily to 9,040 pounds, but this is a major growth limit. Further growth would require

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greater engine power plus major structural and dynamic system changes (e.g., to landing gear, transmission, and/or rotor). (Footnote 10) From this perspective, the LTS 101 provides very limited growth potential.

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(Blank)

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3.1 Proposed Solutions For LTS 101 Problems

As discussed in Chapter 2, component failure and replacement rates for the LTS 101-750B-2 engines installed on the HH-65A are very high. Major problems experienced by the Coast Guard include cracks in the power turbine (PT) wheel, gas producer (GP) wheel blade unwrap, axial compressor blade damage, GP nozzle heat erosion, and oil coking. The USCG has been working with Textron Lycoming to find permanent solutions to these problems under an engine improvement program. In the meantime, some interim fixes have been developed either by Lycoming or by the Coast Guard to improve engine reliability and maintainability.

3.1.1 PT Wheel Cracks

The PT wheel is a one-piece cast disc and blades assembly with an inertially welded shaft. High stress created during the manufacturing process causes cracks at the trailing edge of the root of the blade during transient engine operation.

The configuration of the PT wheel has been revised several times by Lycoming to alleviate this problem. A short-term solution was to use different cool-down rates for the blades and the disc during the manufacturing process. These different cooling rates create a favorable residual stress pattern between the blades and thc disc, and hence serve to attenuate the stresses experienced during transient engine operation.

The monolithic wheel also exacerbates resonances and vibrations, which further aggravate wheel crack. For a permanent solution to this problem, Lycoming changed the design of the PT wheel by adopting inserted cored blades and using different materials for the blade and the disc. The new design damps the vibration of the blades and eliminates the thermally induced stress at the root of the blade during transient engine operation. The blade is more open, with higher camber and reduced tip area. The disc has a wider rim and is made of a special alloy, Waspally. To match the new PT wheel, a redesigned smaller PT nozzle is used.

The rebladeable PT wheel is projected to have an FAA life limit at introduction of 5000 hours, subsequently increasing to 10,000 hours. (Footnote 11)It received FAA approval in August 1989, with initial delivery of production wheels scheduled (Page 20) for December 1989. (Footnote 12) Projected unit cost to the Coast Guard (in 1988 dollars) is about $22,200 for the PT wheel and $4,200 for the PT nozzle.(Footnote 13)

3.1.2 - GP Turbine Blade Unwrap and Blade Tip Separation

There are two problems with the GP turbine blade: blade unwrap; and blade tip separation. Blade unwrap occurs gradually during engine operation as the result of the high centrifugal force acting on the trailing edge of the tip of the airfoil. Blade unwrap can be detected by a very gradual loss of power. Blade tip separation due to stress rupture occurs in the vicinity of the leading edge of the tip of the blade, and may lead to excessive vibrations.

The problems have been traced to insufficient high temperature strength of the blade. Lycoming is adopting a single crystal process for manufacturing the blades, and changing the blade material, with expectation of a nine-fold increase in stress rupture life.

The single crystal blade has a projected life limit at introduction of 2400 hours, increasing in 1995 to 3600 hours (Footnote 14). Test cell evaluation of the single crystal blade is in progress. The certification process for the new blade is underway. FAA approval is expected during the first quarter of 1990 (Footnote 15), and first production availability is expected during the following quarter (Footnote 16). There are 40 blades on each GP disc, and the projected cost per blade in 1988 dollars is $540 (Footnote 17).

3.1.3 - Axial Compressor Blade Damage

Damage to the axial compressor includes blade cracking and foreign object damage (FOD), involving nicks, scratches, and erosion. Blade cracking occurs on cast axial compressors due to fatigue failure caused by a stress riser from a material defect. Solutions to this problem include improved materials and manufacturing processes. FOD-related nicks and scratches can lead to fatigue failure and blade erosion that reduce compressor performance.

To reduce blade cracking, Lycoming has changed from a cast axial compressor to a wrought axial compressor. Replacement of cast axials with wrought axials is in progress.

To reduce FOD, a particle separation device would be required. This would increase the weight of the engine and have a detrimental effect on engine power and (Page 21) performance. Given the USCG's current mission and aircraft configuration, a particle separator is not deemed feasible. Lycoming has not proposed a solution for the FOD problem.

3.1.4 - GP Nozzle Heat Erosion

Some GP nozzles were found to be cracked and burned by heat during engine operation. In response, Lycoming is developing a new GP nozzle with improved air cooling and a material change. Ring seals also will be redesigned to minimize gas leakage. Fuel nozzles with a narrow spray angle will be used to reduce measured gas temperature (MOT) variability. In the interim, the USCG has been coating the GP nozzle with zirconium oxide to provide a thermal barrier and reduce heat erosion.

The redesigned GP nozzle is projected to provide 2400 hours mean time between removals (MTBR) at initial fielding, increasing sequently to 3000 hours (Footnote 18). First production availability of the new nozzle is expected in the first quarter of 1993 (Footnote 19), with the unit cost to the USCG in 1988 dollars projected at $16,200 (Footnote 20).

3.1.5 - Oil Coking

Oil coking occurs in the rear bearing support housing (RBSH) as engine oil subjected to very high temperature forms carbon. This carbon clogs filters, restricts oil flow, scores mating surfaces, and breaks down seals. Oil coking remains a critical problem in the maintenance of the LTS 101 engines; approximately 20 percent of unscheduled engine removals is oil coking-related.

As an interim solution to the oil coking problem, Lycoming developed and is producing an anti-coking seal package with increased air flow for bearing cooling. In addition to this new seal package, the USCG is using a higher temperature tolerant oil (Mobil 254) to reduce coking, and is planning on using a 3-micron oil filter kit to remove from the circulating oil carbon particles caused by coking. Lycoming also has suggested preheating the oil to 200 degrees Fahrenheit before engine start to prevent the contaminated oil from bypassing the filter element (via a relief valve) during cold start.

For a permanent solution to the oil coking problem, Lycoming is in the process of redesigning the RBSH to insulate the oil passages, and is using a new MGT harness for improved temperature measurement accuracy that will prevent oil overheating. Projected scheduled maintenance at initial fielding of the redesigned

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RBSH is 2400 hours, increasing to 4800 hours in 1995 (Footnote 21). Fabrication and assembly of the new RBSH is underway. Bench mark tests are scheduled for late 1989. Certification of the redesigned RBSH is expected in July 1990 (Footnote 22), with first production availability scheduled for the third quarter of 1990. (Footnote 23) Unit cost of the RBSH to the Coast Guard is projected to be $29,400. (Footnote 24)

3.1.6 - Summary of Major Component Problems and Solutions

Table 5 summarizes the major LTS 101 component problems, solutions to these problems, unit costs, and current status.

... Table 5 - Summary Of Major LTS-101 Problems and Solutions

3.2 - Technical Risk

An assessment of the likely success of the LTS 101 improvement program must include an assessment of technical feasibility and risk. Generally, there is relatively low risk associated with designs utilizing available technologies, or supported by extensive successful test results. Designs that apply new and largely unproven technologies, on the other hand, would have much higher risk. From this perspective, the technical risks associated with the LTS 101 improvement program are judged to be low. For example, the use of insertable blades in PT wheels is commonly used in the gas turbine industry to allow for different rates of expansion between the disc and the blade. Single crystal blades are already being used in GP turbines to increase stress rupture life. Lycoming's tests on fuel nozzles with a narrow spray angle resulted in reduction in hot spot temperatures and MGT variability. Field experience shows that the wrought axial compressors have achieved 300,000 LTS 101 fleet hours without failure.

If the proposed improvements are implemented, they should extend component lives and reduce unscheduled engine removals (UERs). By Lycoming's estimate, UERs will drop from the current 1.7 per 1000 hours to 0.9 per 1000 hours by January 1992, and to 0.5 per 1000 hours by January 1995.(Footnote 25) While the accuracy of these forecasts is uncertain, significant reduction in UERs should be expected. The improvements also should increase HH-65A availability and reduce engine maintenance.

3.3 - Schedules

Analysis of the engine improvement program focused on two scenarios designed to represent a realistic range of potential performance. The "best" case assumes that the redesigned parts achieve their full design lives at introduction, that mean time to depot (MTTD) will phase up to 1200 hours at introduction of the last improved part (new GP nozzle), and that there is no schedule slippage. The "worst" case assumes achievement only of half the design life for the new parts, 600 hours MTTD, and one year slippage in certification and introduction of the improved parts. (Footnote 26)

For these two scenarios, the following phase-in schedules are assumed:

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It is also assumed that the "best" case will achieve 1200 hours MTTD by October 1995. For the "worst" case, the 600 hours MTTD will be achieved by July 1995. Note that, because of the lower MTTD, engines are sent to depot more frequently under the "worst" case, and retroDrtting the improved engine parts is completed in a shorter time period.

3.4 - Costs

Costs of maintaining the LTS 101 engines under the "best" and "worst" engine improvement program scenarios were estimated by quarter from 1989 through 2005 (the assumed end of the economic life of the HH-65A airframe) (Footnote 27). These costs include all parts (including newly designed components installed as part of the engine improvement program), a one-time installation cost for the new PT wheel, depot labor, and transportation costs for shipping engines between AR&SC and the field. These costs differ from earlier life cycle analyses in several ways. The current analysis did not include field labor costs or petroleum (fuel), oil, and lubricants. Also, more recent cost information differs from what was available during the conduct of the earlier studies. Some of the basic assumptions, such as the continuing purchase of spares, are also different. The result is that the current study shows lower cumulative costs.

The results of the cost analysis are summarized in Figures 6 and 7(Footnote 28). Figure 6 shows that the cost per engine hour, in constant 1989 dollars, reaches an equilibrium state by 1997 of about $62 and $89 for the "best" and "worst" case engine improvement scenarios, respectively. Compared to the current estimate of $142 per engine hour, this represents a 38-57 percent improvement.

Figure 7 sums these costs over the 1989-2005 analysis period. In discounted 1989 dollars (using a 10 percent discount rate), total costs are estimated at about $69 and $90 million for the "best" and "worst" case scenarios, respectively. Assuming no participation in the engine improvement program and continuation of current maintenance experience, this cost would be about $114 million. Thus, participation in the engine improvement program is projected to save about $24-45 million, or about 21-39 percent.

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... Figure 6 - LTS-101 Maintenance Costs per Engine Hour

... Figure 7 - Engine Improvement Cost Impacts

3.5 - Impacts On Aircraft Availability

There are many factors that affect aircraft availability, relating both to the engine and the airframe. Since delivery of the HH-65A fleet, however, high engine component failure rates, exacerbated by supply problems, have been primarily

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responsible for the poor aircraft availability experience. This history is shown in Figure 8a and 8b, which plot by quarter engine mean time between failures (MTBF) and aircraft availability (percent of aircraft hours in a mission capable status) (Footnote 29).

... Figure 8a - MTBF Trend

... Figure 8b - Availability Trend

The engine MTBF and aircraft availability patterns are similar: both are below their targets, both vary up and down over the past 8 quarters, and both trend

... Figure 9 - Relating Availability to Mean Time to Failure

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generally upward. Using statistical procedures, a trend line was estimated relating MTBF and availability, as shown in Figure 9. The points on the graph show aircraft availability percentage plotted against MTBF for the eight observations (the points do not show a time progression). The thick portion of the line represents the range of observations, and the dashed portion projects this relationship over higher MTBF values. This trend line indicates that the USCG's 71 percent aircraft availability goal would be met at an engine MTBF of slightly over 700 hours. (Footnote 30)

The "worst" and "best" case engine improvement scenarios assume that engine mean time to depot (MTTD) will improve to 600 and 1200 hours, respectively. For the time period for which MTTD data are readily available (the last two quarter s of 1988 and the first two months of 1989), MTTD was closely related to MTBF, averaging 255 hours. Thus, these projected MTTD improvements imply that the engine improvement program will produce better aircraft availability, at worst coming closer to the 71 percent goal, but more likely meeting or exceeding it.

3.6 - Recommendations

(1) Continue with the LTS 101 engine improvement program. The proposed improvements to the LTS 101 engine reflect proven available technology, and the technical risk is judged to be low. The cost analysis projects a savings from the engine improvement program of between $23 and $45 million in cumulative discounted 1989 dollars (10 percent discount rate) from 1989 through 2005.

(2) Defer a decision on the new rear bearing support housing. The cost of the new RBSH for all engines in the fleet would require an expenditure of over $8 million in 1988 dollars, and may not be warranted by the benefits to be derived. This decision should await results of the less expensive solutions being pursued to alleviate the oil coking problem, including the new seal package, use of the 3-micron filter, use of Mobil 254 oil, and preheating the oil before engine start.

(3) Establish a program to closely monitor implementation and results of the LTS 101 improvement program. A program should be designed and implemented to track explicitly the installation and performance of the engine improvement program, especially failure, repair, and replacement rates and costs of the improved components. Information from such a program will be critical to any re-engining decision.

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(4) Conduct an independent audit of the structural design of the new parts. This is an activity that can be carried out at modest cost that would provide the USCG with an independent detailed assessment of how the redesigned components are likely to perform, and would help guard against possible design flaws. Such an audit could be pursued through the Air Force facility at Wright Patterson AFB in Ohio.

(5) Consider the desirability of conducting durability tests on the redesigned components. The design lives of these components are much larger than average annual engine hours; i.e., these lives will not be fully tested for several years in the course of normal operations. Durability testing (running many hours on a test cell) could provide the USCG with a better indication of whether or not the projected design lives are likely to be achieved. Such testing is not inexpensive, however, and the USCG should weigh the benefits against the costs.

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4.1 - Background

4.1.1 - LHX

The U.S. Army's Light Helicopter Program (LHX) is developing a "lightweight, low cost, twin engine advanced helicopter that will retire the current light fleet of tactically obsolescent AH-1, OH-6, and OH-58 helicopters for the primary missions of light attack and armed reconnaissance.'' (Footnote 31) The initial recommendation to replace the current light helicopter fleet with the LHX was made in early 1982, with initial deployment planned for late 1996. Key milestones include the following. (Footnote 32)

Jan. 82 -	Army Aviation Mission Area Analysis recommended replacing the current light fleet with the LHX.
Oct. 83 -	Advanced development effort was initiated under the Advanced Rotorcraft Technology Integration Program.
Nov. 87 -	Independent assessments by The RAND Corporation and the Institute for Defense Analyses both recommended a new development conventional helicopter as the most cost and operationally effective airframe alternative for the LHX.
Oct. 88 -	Contracts were awarded to two contractor teams (Boeing/Sikorsky and McDonnell/Bell) for competitive LHX demonstration/validation.
Dec. 90 -	Planned down-select and contract award for full-scale development of air vehicle.
Nov. 94 -	Planned contract award for initial air vehicle production.
Mar. 96 -	Planned initial air vehicle production delivery.
Nov. 96 -	Planned initial operational capability.

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The Army plans to purchase slightly over 2,000 LHX helicopters. However, both quantity and schedule ar e dependent on future appropriations. Pr ogram funding is being debated in Congress, where it must compete with other military programs within overall budget ceilings.

4.1.2 - T800

The T800 engine program is designed to produce an advanced technology engine for the LHX. It builds on late 1970s engine development programs sponsor ed by the Army and Air Force, and utilizes a competitive approach. Key milestones include the following. (Footnote 33)

Jul. 85 -	Two contractor teams (Avco Lycoming/Pratt & Whitney and Garrett/Allison) received contracts to develop and build prototype or developmental 1200 shaft horsepower class, advanced technology engines (designated as the T800).
Oct. 88 -	LHTEC (Light Helicopter Turbine Engine Company) was announced as the winner of the competitive T800 program. (LHTEC is a partnership of Garrett Turbine Engine Company and the Allison Division of General Motors Corporation.)
Apr. 91 -	Expected DOD qualification, plus FAA certification of a commercial version of the T800. (Footnote 34)
Mar. 92 -	Expected initial LHTEC production capability. (Footnote 35)
Jun. 93 -	Planned initial Army contract for production engines.
Jun. 95 -	Planned initial delivery of production engines to the Army.

The engine is designed for combat situations; i.e., it is designed to be dur able, reliable, responsive, easy to maintain. As shown in Table 6, it is a significantly higher power engine than the 700 skip class LTS 101.

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... Table 6 - T800 power Rating

4.2 HH-65A/T800 PROOF OF CONCEPT

The Coast Guard and the Army have signed a Memorandum of Understanding (MOW) setting forth responsibilities and terms for the development, integr ation, test, procurement, and evaluation of the HH-65A/T800 Proof of Concept. The objectives are to demonstrate the feasibility of installing the T800 engine in the HH-65A and to provide T800 installation, flight and test data. (Footnote 36)

The Proof of Concept is to be conducted in two phases: Phase 1, Survey Phase; and Phase 2, Demonstration/Qualif~cation Phase. Phase 1 will include engine installation and about 50 test flight hours. Installation will require design, modification, and testing, within Phase 1 budget and schedule constraints, of: mechanical systems (engine deck and mounts, output shafting and coupling, cowling, cooling air inlets, exhaust systems, fuel systems, etc.); electrical systems (engine system wiring, cockpit controls and displays, etc.); and control systems, including the engine airframe interface system (EAIS). While design of these modifications would be refined during the subsequent qualification phase, Phase 1 results should indicate if there are likely to be any significant re-engining problems, and should pr ovidc tho USCG with much better estimates of re-engining costs and performance than are presently available.

Under terms of the MOU, the USCG will provide funds for Phase 1 not to exceed $10,000,000 for contracts and U.S. Army support efforts, plus a "cost-free loan of one HH-65A helicopter for modification to accept two T800 engines with appropri-

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ate instrumentation for flight test and demonstration." Three YT800 engines (i.e., preliminary flight rated) plus core spare parts will be supplied by the LMX PMO at no cost to the Coast Guard.

AVSCOM will be the contracting agency for the Proof of Concept, and LHTEC will be the prime contractor. LHTEC's proposal for Phase 1 was received by AVSCOM on November 22, 1989; negotiations are underway, and it is expected that a letter contract for the first six months of effort will be executed in January 1990, with a full contract to follow within 120 days. Completion of Phase 1 is expected within 21 months, by about October 1991.

Qualification or certification of the installation would be done during Phase 2. This has not been costed, but probably would require another 100-200 flight hours and perhaps 18 months. (Footnote 37)

4.3 - Technical Risk Assessment

The T800 appears to be a well designed engine, with low technical risk. It has been under development since 1985, with an excellent record to date of meeting performance and schedule milestones.

The T800 uses proven technologies, and has its roots in earlier development progr ems dating from the late 1970s: the Army's Advanced Technology Demonstrator Engine (ATDE) Program, and the Air Force Engine Structural Integrity Program (ENSIP).38 It has been test flown on an Agusta 129, and additional installations and flight tests are being planned.

4.4 - Potential Re-Engineering Schedules

Figure 10 summarizes:

• LHTEC and Army schedules;
• a "short" (optimistic) USCG re-engining schedule; and
• a "long" USCG re-engining schedule.

The "short" schedule represents probably the fastest feasible schedule for reengining the HH-65A with the T800. It is not an unrealistic schedule, but it

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... Figure 10 - T800 Re-Engineering Schedules

assumes relatively optimum performance of all steps that would need to precede reengining.

• The Phase 1 Proof of Concept will be completed successfully, with a slightly expedited schedule (18 versus 21 months as currently proposed).
• A decision to re-engine will be made promptly at the end of the Phase 1 Proof of Concept. (Key cost and performance information needed for this decision should be available at this time.)
• A MIPR (Military Interdepartmental Purchase Request) will be used to transfer money to the Army, and the Army will purchase engines for the Coast Guard under the terms of its contract with LHTEC. (Footnote 39)
• Budget and procurement actions will be accomplished expeditiously; a contract with LHTEC for USCG engines will be executed 12 months after completion of the Phase 1 Proof of Concept.
• LHTEC will deliver the initial engines 18 months from contract execution. (Footnote 40)
• Re-engining of the fleet will be accomplished at a rate of three aircraft per month (i.e., over a period of two years and eight months for all 96 aircraft).

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The "long" schedule assumes that each of the above steps will take somewhat longer than assumed for the "short" schedule. It is not the most pessimistic schedule that can be envisioned, in that it assumes that no extraordinary problems will he encountered, but it is felt to represent the high end of a "reasonably expected" range. It also assumes that re-engining will occur at a rate of two aircraft per month, requiring four years in total.

Key observations include the following.