Appendix C
Key Recommendations from Previous Studies

In its research for this report the committee looked at several studies of re-engining. Table C-1 lists the key studies, which are summarized in this appendix.

TABLE C-1 Previous Air Force Re-engining Studies

No.

Study Name

Prepared by

Date

1

Technology Options for Improved Air Vehicle Fuel Efficiency

Air Force Scientific Advisory Board

May 2006

2

B-52 Propulsion Capability Study

ACSSW/PRSS New Engines

November 2005

3

C-130 Enhanced Capabilities/Demonstration Programs

Snow Aviation International

October 10, 2005

4

AC-130U Alternate Engine Summary Report

Macaulay Brown/UTC

March 8, 2005

5

Task Force on B-52H Re-engining (Revised and Updated)

USD/ATL

2004

6

TF33 Re-engine Look-Ahead

Oklahoma City Air Logistics Center

June 2004

7

The Airforce KC-767 Tanker Lease Proposal: Key Issues for Congress

Congressional Research Service

2003

8

B-52 Re-engine Study Report

Boeing/Hannon Armstrong

September 30, 2003

9

B-1B Re-engining, Mission Flexibility (for Maj Gen Dan Leaf)

Boeing

July 29, 2002

10

KC-135 Engine Modernization Program: LCC Analysis

Boeing

March 9, 2000

11

TF33 Propulsion System Roadmapping Study

Pratt & Whitney

February 10, 1998

12

Findings of the B-52H Re-engining Cost IPT

SAF/FM

1997

13

Analysis of Aerial Tanker Re-engining Programs

Congressional Budget Office

September 1984

NOTE: ACSWW, Agile Combat Support Systems Wing; PRSS, Propulsion Systems Squadron; SAF/FM, Assistant Secretary of the Air Force (Financial Management and Comptroller); USD/ATL, Undersecretary of Defense Acquisition, Technology, and Logistics; UTC, United Technologies Corporation.



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Improving the Efficiency of Engines for Large Nonfighter Aircraft Appendix C Key Recommendations from Previous Studies In its research for this report the committee looked at several studies of re-engining. Table C-1 lists the key studies, which are summarized in this appendix. TABLE C-1 Previous Air Force Re-engining Studies No. Study Name Prepared by Date 1 Technology Options for Improved Air Vehicle Fuel Efficiency Air Force Scientific Advisory Board May 2006 2 B-52 Propulsion Capability Study ACSSW/PRSS New Engines November 2005 3 C-130 Enhanced Capabilities/Demonstration Programs Snow Aviation International October 10, 2005 4 AC-130U Alternate Engine Summary Report Macaulay Brown/UTC March 8, 2005 5 Task Force on B-52H Re-engining (Revised and Updated) USD/ATL 2004 6 TF33 Re-engine Look-Ahead Oklahoma City Air Logistics Center June 2004 7 The Airforce KC-767 Tanker Lease Proposal: Key Issues for Congress Congressional Research Service 2003 8 B-52 Re-engine Study Report Boeing/Hannon Armstrong September 30, 2003 9 B-1B Re-engining, Mission Flexibility (for Maj Gen Dan Leaf) Boeing July 29, 2002 10 KC-135 Engine Modernization Program: LCC Analysis Boeing March 9, 2000 11 TF33 Propulsion System Roadmapping Study Pratt & Whitney February 10, 1998 12 Findings of the B-52H Re-engining Cost IPT SAF/FM 1997 13 Analysis of Aerial Tanker Re-engining Programs Congressional Budget Office September 1984 NOTE: ACSWW, Agile Combat Support Systems Wing; PRSS, Propulsion Systems Squadron; SAF/FM, Assistant Secretary of the Air Force (Financial Management and Comptroller); USD/ATL, Undersecretary of Defense Acquisition, Technology, and Logistics; UTC, United Technologies Corporation.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft SUMMARY 1 TECHNOLOGY OPTIONS FOR IMPROVED AIR VEHICLE FUEL EFFICIENCY AIR FORCE SCIENTIFIC ADVISORY BOARD CHAIR: ANN KARAGOZIAN MAY 2006 Scope This study identifies potential near-, mid-, and far-term methods for improving air vehicle fuel efficiency in the Air Force. The study also determines relevant benefits of recent government propulsion efficiency programs and technologies (current and future) that could impact fuel efficiency. Background Between 2005 and 2025, the percentage of crude oil imported to the United States is estimated to grow from 63 to 70 percent of the total crude oil consumed. Within DoD, the Air Force is the largest consumer of fuel, with 58 percent, or 3.2 billion gallons, used in 2003. Of this, 81 percent was used for fueling aircraft. The largest percentage (54.2) of aircraft fuel is used by tankers and transport planes (FY98-FY04). In the study, the cost of fuel is estimated by including the actual cost (Defense Energy Support Center (DESC) price to the Air Force) as well as the cost to transport the fuel via tanker. The cost to transport the fuel can be significantly higher than the actual fuel cost. Therefore it is necessary to account for this “fully burdened” cost of aviation fuel when comparing benefits of alternative solutions. Findings Fuel efficiency can be increased by making adjustments in three areas: aerodynamics (to increase lift to drag ratio), engine fuel consumption (to decrease thrust-specific fuel consumption (TSFC)), and weight (to reduce operational empty weight). It is estimated that large transport aircraft could realize as much as a 12 percent savings in fuel if there is a 10 percent increase in lift to drag ratio, a 13 percent savings for a 10 percent decrease in TSFC, and a 6 percent savings for a 10 percent decrease in operating empty weight (OEW). This information was calculated for an aircraft at Mach 0.8 at an altitude of 36,000 ft. Over the past 50 years or so, the TSFC of engines has tended to decrease over time, starting with turbojet engines in the 1950s and ending with second-generation, high-bypass turbofans in the early 2000s. The potential for further gains in TSFC is projected to decrease in the next 15 years. However, tankers and transport aircraft tend to have a higher lift to drag ratio and lower TSFC than fighter aircraft, making them better candidates for TSFC improvement. Current Programs Current Air Force turbine engine development programs (IHPTET and VAATE) plan to improve engine performance over the next 10 years. These programs generally emphasize goals for military performance, not mobility. NASA aeronautics development programs are focusing on emissions, noise reduction, and engine control as well as ultraefficient engine technology (UEET). UEET has achieved a

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Improving the Efficiency of Engines for Large Nonfighter Aircraft 15 percent reduction in carbon dioxide emissions for subsonic transports. Any focus on NOx reduction can work against fuel efficiency. Recommendations The study offers near-, mid-, and far-term recommendations as well as a way to measure the benefit/cost ratios in five areas: engines, aerodynamics, structures and materials, operations, and alternative fuels. SUMMARY 2 B-52 PROPULSION CAPABILITY STUDY MARK AMOS, MIKE BURKE, PERRY SHELLABERGER, AND LT COL GREG WEYDERT AGILE COMBAT SUPPORT SYSTEMS WING (ACSSW) PROPULSION SYSTEMS SQUADRON (PRSS) NEW ENGINES NOVEMBER 2005 Introduction The B-52 is to remain in service through 2045. In 2005, the fleet included 76 B-52 aircraft with a total of 608 TF33-PW-103 engines as well as engine spares. Sustaining these TF33 engines is expected to become increasingly difficult as time goes by. Any B-52 re-engining solution must maintain the necessary aircraft capabilities and be able to accommodate future equipment modifications. Changes in the B-52 platform could include changes to the initial operational capability (IOC) of the standoff jammer, expected between 2012 and 2014, and to the next-generation, long-range-strike capability, as well as changes in mission needs. Re-engining in the 2012-2014 time frame would allow for the utilization of full engine life before the B-52 system is retired. Relevant Previous Studies 1997, GAO B-52 cost effectiveness study 1998, LPJ study (TF33 Propulsion Roadmap) 1998, Pratt & Whitney study (TF33 Propulsion System Roadmap) 1998, Boeing re-engining study 2002, Defense Science Board re-engining study 2002, update to LPJ 1998 study 2004, update to DSB re-engining study Proposed Study Scope It was proposed that a study be undertaken that focuses on increasing the capability of the B-52 through re-engining while minimizing air vehicle impact and development risk. The study would concentrate on re-engining options that maintain the current B-52 aircraft/engine pylons and nacelles as well as TF33 takeoff thrust capability. It was also proposed that three re-engining options be explored: a complete TF33 core upgrade, a TF33/F119 hybrid upgrade, and a complete upgrade using military

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Improving the Efficiency of Engines for Large Nonfighter Aircraft derivative engines (F119, F110, etc.). The estimated cost of this study was $125,000 depending on the approved final scope of the study. The results of a preliminary study could define the next step, perhaps requests for information (RFIs) and concepts for evaluation of the industry. Proposed Study Figures of Merit Ideally, any re-engining solution would provide a 10 percent improvement in TSFC, an average time on wing (ATOW) between 3,500 and 4,000 hours, and a 1 MW increase in power capacity. The re-engining program would also facilitate improvements in operating altitude, loiter, range, weapon/load delivery, hot-day takeoff, reliability, and maintainability of the B-52. SUMMARY 3 (DRAFT) C-130 ENHANCED CAPABILITIES DEMONSTRATION PROGRAMS BRIEFING TO C-130 TCG WORLDWIDE REVIEW SNOW AVIATION INTERNATIONAL (SAI) MARIETTA, GEORGIA OCTOBER 10, 2005 Scope This study summarizes demonstrations of the tip tank (complete in September 2004), the unmanned aircraft system (UAS) AirLaunch (complete in April 2005), the short takeoff and landing (STOL) Herk (ongoing, July 2005 through October 2006), and the PW150 re-engining (pending) on the C-130 aircraft. Tip Tank Demonstration Tip tanks decreased the stall speed of the C-130 without increasing overall drag. The demonstration established the flutter-safe envelope, the structural response (during taxi and in flight), and the new C-130 flying characteristics. A summary of the aircraft stall and lift coefficient performance and the resulting inferred performance improvements are included. UAS AirLaunch Demonstration Pictures are provided of the UAS airborne and after release from the aircraft. STOL Herk Demonstration The STOL Herk program objectives include demonstrating the feasibility of the hybrid propulsion system and measuring the performance increases attributable to the installation of NP2000 propellers and the addition of two Pratt & Whitney 306C turbofans to a C-130E with T56-7A/B engines. The STOL Herk test bed provides a location to measure pressure flows on new C-130 nacelles; to create aerodynamic modifications for safe operation at lower airspeeds (and with critical engine failure); and to rewire and modernize key electrical system components. The NP2000 propeller is described in detail, along with the existing STOL Herk avionics, nacelles, and aerodynamic modifications. The NP2000 propeller provides more thrust and more wing lift through

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Improving the Efficiency of Engines for Large Nonfighter Aircraft aspiration than the 54H60 propeller. NP2000’s better aspiration of the wing enables C-130 aircraft to fly 12 knots slower than the original stall speeds. Aerodynamic devices assure roll and yaw control during slow flight, in engine-out situations, and during takeoff (without power cutbacks). A C-130 with an extended chord and aileron provides more aileron effectiveness than a standard C-130 to mitigate engine failure. An extended chord, rudder, and dorsal area counter the greater thrust asymmetry created by outboard engine failure at slow speed and heavy weight; NP2000 software reduces the thrust decay of a failing engine, giving the pilot more time to respond. Finally, rudder effectiveness is increased via strakes and dorsals. Conclusions The high-flight-time ex-Southern Air Command transport L-100 has flown 90,000 hours, which confirms the attainability of C-130 life extensions and the airworthiness of the basic design. The SAI C-130 modern technology insertion demos and their sponsorship by DoD show a strong shared commitment to keeping legacy C-130 fleets viable and operationally effective for decades to come. SUMMARY 4 AC-130U ALTERNATE ENGINE SUMMARY REPORT MACAULAY BROWN/UNITED TECHNOLOGIES CORPORATION MARCH 8, 2005 NOT FOR PUBLIC RELEASE SUMMARY 5 TASK FORCE ON B-52H RE-ENGINING (REVISED AND UPDATED) OFFICE OF THE UNDER SECRETARY OF DEFENSE FOR ACQUISITION, TECHNOLOGY, AND LOGISTICS DEFENSE SCIENCE BOARD WASHINGTON, D.C. 2004 Study Scope The task force was asked to review and advise on key aspects of the policy and technology issues associated with re-engining the Air Force’s B-52 fleet. Specifically, the task force examined relevant aspects of B-52 re-engining, including its impact on B-52 capability and demand for tanker support; fuel consumption; reliability, supportability, and availability; technical risks of re-engining; and financing options, including the use of Energy Savings Performance Contracting (ESPC). Conclusions The B-52H is the most versatile and cost-effective bomber in the inventory and re-engining makes it even more so. The B-52H has the highest mission-capable rate of any of the three bombers, and is the only Conventional Air Launched Cruise Missile (CALCM) capable platform in the inventory.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft That further significant reductions in the B-52H fleet are unlikely for the foreseeable future because: The total assigned inventory (TAI) bomber fleet being reduced from 130 to 96, a deminimis number There is no bomber aircraft currently in development The B-52H is highly capability of accomplishing its assigned missions The B-52H is flexible and able to adapt to future missions The USAF chose to retire more than twice as many B-1 airframes as B-52H airframes USAF has stated its intention to retain the B-52H through 2037 B-52H re-engining program represents low risk in the areas of program management, systems engineering, and affordability based on a re-assessment of the factors considered in the 1996 IPT evaluation. B-52H re-engining is an attractive opportunity for the following financial and operational reasons: Greater operational flexibility Greater range Reduced fuel burn Reduced tanker demand Depot savings through elimination of off-airframe engine maintenance Field maintenance manpower savings B-52H re-engining would serve as a good pilot program for expanding the ESPC Program in practice beyond facilities, and into mobility systems. The task force concludes the economic and operational benefits far outweigh the program cost. Recommendations The task force recommends that the following actions should be taken to produce a promptly executable B-52 re-engining program, recalibrate the expected lifetime of the airframe, and quantify the logistics assets that could be redeployed to satisfy shortfalls elsewhere: The Air Force proceed with B-52H re-engining without delay and place the program on a fast acquisition track in order to maximize the benefits and take advantage of the current business climate. The Air Force proceed with a dedicated study to determine the optimum program, considering all the possible engines, service arrangements and financing options. OSD commission a new independent long-term tanker requirements study that extends beyond FY05, based on new planning guidance, which includes the ability to conduct sensitivity analyses of B-52H re-engining as well as other planned and potential new receiver aircraft that will be in service over the expected lifetime of the tanker force, such as JSF. The SPO and Boeing investigate the impact of eliminating low-level missions on projections of future airframe economic lifetime. OSD and the Air Force investigate whether authority exists to use an Energy Savings Performance Contract or if legislative clarification is needed; and confirm the economic viability of Energy Savings Performance Contracting as a financing mechanism for B-52H re-engining.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft OSD investigate the use of more robust analytical tools that allow the value of improved operational capabilities to be included in cost-benefit analyses used to support programmatic decision making. Better analytical tools that quantify the logistics demands resulting from the deployment, employment, and sustainment of platforms will enable more informed force structure decisions and result in greater operational capability and flexibility for DoD’s Total Obligation Authority. SUMMARY 6 TF33 RE-ENGINE LOOK-AHEAD OKLAHOMA CITY AIR LOGISTICS CENTER TEAM TINKER JUNE 2004 Background Re-engining the TF33 fleet has been heavily evaluated in depth. Several re-engining studies have been undertaken since 1996. These studies include but are not limited to: 1996, Boeing re-engining proposal 1998, Director Martha Evans (SAF/AQI) initiated TF33 roadmap study 2002, Propulsion Development Systems Office’s Advanced Division (ASC/LPJ) tasked to update 1998 SAF/AQI study 2003, JSTARS re-engining requesting funds 2003, B-52H re-engining requesting approval Study Focus Lt Gen Wetekam, AF/IL, has requested a look-ahead at the feasibility of a fleetwide re-engining of the TF33. The look-ahead evaluation focuses on the pros and cons of each study. Summary of the Benefits (Pros) Studies have shown that re-engining can increase the reliability of an aircraft by up to 10 percent while increasing fuel efficiency between 19 and 29 percent. This leads to increased mission capability (increased mission capable) rates and mission altitude, decreased time to climb and required tanker support). Re-engining the fleet can also lead to environmental improvements such as reduced noise and emissions. Finally, the TF33 is capable of meeting its mission through the lifetime of all aircraft in the studies. Summary of Detriments (Cons) The economic payback of a TF33 re-engining investment can be as long as 20 to 30 years, and the cost savings are based on a reduced tanker fleet. In turn, the workload (manpower) loss must be offset; this may entail significant reductions in force (112 MAE/43 LPA) and have significant consequences for active duty, reserves, and guard personnel. Potential workload and manpower losses from FY04 to FY24 are summarized in a chart.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft Conclusions Re-engining the TF33 allows for many mission improvements. However, the cost of the program does not justify it. Repeated studies have reached this same conclusion. Any full-scale evaluation of the TF33 would require assistance from the Aeronautical Systems Center. SUMMARY 7 THE AIR FORCE KC-767 TANKER LEASE PROPOSAL: KEY ISSUES FOR CONGRESS CONGRESSIONAL RESEARCH SERVICE (CRS) THE LIBRARY OF CONGRESS WASHINGTON, D.C. 2003 Introduction The Air Force wished to replace its KC-135E aircraft by leasing 100 new Boeing KC-767 tankers. It indicated that leasing was preferred because it would result in faster deliveries than outright purchase. Air Force leaders argued that a lease would allow it to husband scarce procurement dollars by making a small down payment. Although Congress authorized the proposed lease in the FY02 DoD Appropriations Act, it stipulated that the defense oversight committees must approve the lease. However, the Senate Armed Services Committee had not yet done so. The lease proposal was controversial, and a number of issues have been raised so far. Is There an Urgent Need to Replace the KC-135 Fleet? The Air Force stated that replacing the KC-135 was urgent, citing high costs, aircraft vulnerability to catastrophic problems, and the imminent closing of the 767 production line. Opponents of the lease stated that operating costs were controllable and would be far lower than the overall costs of leasing the 767; that the vulnerability was no more than that depicted in a 2-year-old study, which the Air Force had found acceptable; and that the 767 production line was viable until 2006-2008. Is the KC-767 the Best Aircraft to Replace the KC-135? If acquired, the KC-767 might be in DoD’s inventory for 50 years. The Air Force said the KC-767 was much more capable than the KC-135. Opponents contended other aircraft were even better than the KC-767 in meeting the Air Force’s requirements. The Air Force opposed re-engining KC-135Es, but opponents believed the idea merited attention, as did outsourcing aerial refueling. Is the Air Force Cost Comparison Authoritative? The Air Force’s report to Congress calculated that a 767 lease would cost $150 million more than a purchase on a net present value (NPV) basis. This calculation, however, was sensitive to many assumptions. The CRS analysis showed that several assumptions built into its calculation would, if treated different from how they were treated in the Air Force report, change the calculation by hundreds of

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Improving the Efficiency of Engines for Large Nonfighter Aircraft millions of dollars each. Although some assumptions could change the calculation to favor either the lease or the purchase, others—such as the discount rate used to calculate NPV and whether to use multiyear procurement for the purchase option—could be more likely to tip the comparison in favor of the purchase option. Does This Issue Have Implications for Congressional Budget Oversight? The proposed lease appeared to be an unprecedented method of funding major new defense procurements. Critics pointed out that this approach was coupled with exemptions from longstanding laws on budgeting and defense procurement. The proposed lease raised policy questions about the visibility of full costs for DoD programs in the congressional oversight process, including questions about locking in budgetary resources when costs are uncertain, appropriateness of using an operating lease for the proposal, the impact of a Special Purpose Entity, and the potential for deviation from full funding of the government’s contractual liability. Figures and Tables This report also contains many figures and tables of interest. Figures KC-135 Annual Cost Forecast KC-135 Projected Aircraft Availability Cost of Lease Payment and Total Lease Program, FY2003-FY2017 KC-135 Cost Projections from 2001 (ESLS) and 2003 (BCA) DC-10 Availability Boeing 767 and Airbus A330 Production Backlog Projected 767 Production Boeing Civil Airframe Production Boeing Commercial Airplanes Direct Employment Tables Aerial Refueling and Combat in Two Conflicts Projected Aircraft Availability KC-767 and Civil 767 Profits Discount Rates for “Lease vs. Purchase” NPV Comparisons Summary of Variables, Assumptions, and Potential Changes in NPV Cost Calculation Comparison of “Lease vs. Buy” Options for the Tanker Lease Program (Air Force Assumptions) How Interest Rates Change 767 Tanker Lease Program Costs Estimated Air Force Termination Liabilities, 2003-2017 Cost of “Lease vs. Multiyear Buy” and Alternate Assumptions

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Improving the Efficiency of Engines for Large Nonfighter Aircraft SUMMARY 8 B-52 RE-ENGINE STUDY REPORT BOEING/HANNON ARMSTRONG SEPTEMBER 30, 2003 NOT FOR PUBLIC RELEASE SUMMARY 9 B-1B RE-ENGINING MISSION FLEXIBILITY (FOR MAJ GEN DAN LEAF) BOEING JULY 29, 2002 Maj Gen Dan Leaf asked Boeing to find the best solution to increase B-1B mission flexibility, specifically with increased altitude capability. Boeing studied many aircraft modifications and subsystem upgrades and concluded that F119 re-engining was the best solution. The conclusion of the study was that the original B-1A altitude and Mach 2.2 speed (which the B-1B structurally inherited) could be restored with the increased specific thrust of the production F119 engine. SUMMARY 10 KC-135 ENGINE MODERNIZATION PROGRAM: LCC ANALYSIS BOEING MARCH 9, 2000 Executive Summary Oklahoma City Air Logistics Center (OC-ALC) completed a cost study in 1996 regarding the cost effectiveness of replacing the existing TF33-P102 engines with the CFM56 engine. The 1996 study concluded that the modification was not cost effective and indeed would cost the Air Force $974 million NPV more than its projected cost. The 40-year life cycle cost (LCC) in this study differed from the 1996 study by over $2 billion (NPV) and showed re-engining with the CFM56 to be the most cost-effective solution. Re-engining the remaining KC-135Es would have saved the Air Force approximately $3 billion in FY99 and approximately $7 billion then year (TY). Methodology The 1996 OC-ALC Excel LCC model was duplicated by copying the modeling parameters and manipulation techniques from the LCC spreadsheets furnished within the 1996 study (described in detail in Attachments D and E of original report.) However, the 1996 study was based on several key assumptions that time proved to be incorrect: Total engine removal (TER) rate of the TF33-W-P102 was assumed to be 0.55 removals per 1,000 engine flight hours. In fact, the TF33-W-P102 removal rate exceeded 0.55 every year since 1994 and has averaged over 0.70 since the 1996 study was completed.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft The TER rate was modeled in the 1996 study as steady state—that is, as never increasing over the next 40 years. Analysis of historical data reveals the TER rate has increased an average of 3.8 percent annually since 1985. Engine overhaul costs (EOCs) of the TF33-W-P102 were assumed to be $356,568. Actual overhaul costs have averaged $450,000 since the 1996 study was completed. EOCs in the 1996 study were also modeled as steady state and forecast not to increase over the next 40 years. Analysis of historical costs reveals that overhaul costs have actually increased over 6.7 percent annually since 1990 and 17.9 percent annually since the 1996 study was completed. Changes in TERs and EOCs produced increases in engine support costs, which rose, on average, 13.2 percent annually since 1990 and over 18.5 percent annually since 1995. In this study, Boeing used the 1996 LCC study assumption, incorporated 3 additional years of actuarial engine support costs, applied a modest 4 percent annual engine support cost growth due to aging, and reduced the KC-135E conversion cost to $1.8 million. Nonmonetary Benefits and Savings This analysis focused on quantifiable engine support costs. However, the single tanker configuration led to additional nonmonetary benefits and savings: Logistics support infrastructure (reductions) Parts and support equipment inventory reduction, Technical order standardization, Airframe depot maintenance streamlining, Less crew training and fewer training materials, Smaller logistics deployment footprint, Large commercial population, Part obsolescence concerns eliminated, Commercial support options now viable, Relieves TF33 depot floor space shortage, Slower growth in engine support cost, Commercial engine service bulletin and technical advisories, Engine improvement costs shared with commercial sector, and Fifteen known deficiencies in TF33 management plan eliminated. Operational benefits (improvements) Greater fuel offload capability, Greater loiter capability, Shorter takeoff distance, Increased engine reliability, fewer in-flight shutdowns, Rotor burst containment inherent to design, Meets Stage III (current) and Stage IV (future) noise requirements, The usability of JP-8 in cold weather, Increased operations from additional airfields, and Less deployment planning needed.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft SUMMARY 11 TF33 PROPULSION SYSTEM ROADMAPPING STUDY PRATT & WHITNEY FEBRUARY 10, 1998 NOT FOR PUBLIC RELEASE SUMMARY 12 FINDINGS OF THE B-52H RE-ENGINING COST INTEGRATED PRODUCT TEAM (IPT) ASSISTANT SECRETARY OF THE AIR FORCE FINANCIAL MANAGEMENT OFFICE 1997 Summary The OC-ALC Financial Management division estimates the cost for re-engining the B-52H at $1.34 billion (including risk uncertainties), with a budget estimate (including only identifiable sources) at $2.128 billion. Two options for re-engining the B-52H are considered: a baseline purchase option and a leasing option. In the baseline purchase option, cost is analyzed by area as follows: depot (engines and aircraft), sustainable support (cost improvement programs and modifications), field level (personnel and material), fixed logistics (training and technical orders), aviation fuel, and time-critical technical orders (TCTOs). In the leasing option, costs are analyzed in the following areas: development and testing (FY97-FY01), products and installation (FY99-FY08), lease (FY01-FY36), Air Force program support (FY97-FY36), contractor logistics support (FY01-FY36), mixed fleet support (FY97-FY08), and, finally, aviation fuel. Some cost areas are identified as high risk. These are areas where costs can be only poorly predicted—namely, TERs, depot cost per engine for two-level maintenance, modifications, TCTOs, and fuel inflation. Average and three-sigma values are assigned to these risk areas. Using a risk-adjusted fuel index of 3.1, the leasing option will cost as much as or significantly more than maintaining the status quo over the next 30 years. Specifically, the total obligational authority for risk, lease, and buy is $8.608 billion, $9.922 billion, and $7.761 billion (FY97-FY37), respectively. Using a risk-adjusted fuel index of 2.7, the leasing option will be significantly higher than the budget estimate in the next 30 years. The risk-adjusted cost baseline, lease adjusted for fuel uncertainty, and the budget baseline total obligational authority for FY97-FY37 is $8.608 billion, $9.560 billion, and $7.432 billion, respectively. Conclusion The range of risk in the cost estimation is $465 million to $2.878 billion. Switching to a leasing option adjusted for fuel cost risk instead of a risk-adjusted purchase option would cost $1.314 billion.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft SUMMARY 13 ANALYSIS OF AERIAL TANKER RE-ENGINING PROGRAMS CONGRESSIONAL BUDGET OFFICE (CBO) SEPTEMBER 1984 As requested by the Subcommittee on Defense of the House Appropriations Committee, this paper discusses some of the issues associated with the re-engining of the KC-135 aircraft and illustrates the costs and effects of alternative approaches to re-engining. In accordance with CBO’s mandate to provide objective analysis, no recommendations are made. In 1984, the Air Force had approximately 615 KC-135 aircraft, which accounted for the bulk of its tanker fleet. Two programs to replace the engines in these aircraft represented a multi-billion-dollar effort to maintain tanker viability. The first program, directed by the Air Force, replaced the J57 engines on KC-135As with new CFM56 engines (KC-135R). The second program, directed by Congress, salvaged and refurbished Pratt & Whitney JT-3D engines and related equipment from retired Boeing 707 aircraft to replace aging engines on the KC-135A (KC-135E). Capability According to official estimates by DoD, the fuel delivery capacity of the re-engined KC-135R would increase by an average of 50 percent over that of the existing KC-135A; fuel efficiency was expected to increase by 25 percent. The JT3D re-engining program was expected to increase fuel delivery capacity of the KC-135Es by an average of 20 percent over that of the KC-135A and fuel efficiency by about 12 percent. Both the KC-135E and the KC-135R required a shorter takeoff distance at maximum gross weight than the KC-135A, enabling tankers to land at additional airfields. Cost Without accounting for differences in capability, CFM56 re-engining was much more costly than JT3D re-engining. An undiscounted 20-year LLC (excluding research and development) was $57.9 million for the KC-135R and $46.7 million for the KC-135E. After applying DoD estimates of relative fuel delivery capacity (in KC-135A equivalents), the LLC per A equivalent (including acquisition) became very similar: $38.6 million for the KC-135R and $38.9 million for the KC-135E. These cost estimates were sensitive to fuel costs as well as tanker performance—which, in turn, depended on the range and type of tanker mission. Availability of the Aircraft for Re-engining Since the JT3D program involved salvaging and refurbishing existing commercial engines and other aircraft components, it was ultimately limited by the supply of donor Boeing 707 aircraft. Aging The desirability of investing in a re-engining program might have been influenced by the age of the KC-135 aircraft and the likely time required to complete the re-engining program. Also, if a new-generation tanker was needed to support a smaller but more advanced bomber force, it might have been important to consider cost-effective alternatives for tanker re-engining.

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Improving the Efficiency of Engines for Large Nonfighter Aircraft Support Requirements Some concern was expressed by the Air Force about problems of logistics support for the JT3D engines. Timing of Capability and Demand Fluctuations in refueling demand as well as in demand to support general-purpose forces might have dictated the time frame during which re-engining was feasible. Implications for the Guard and the Reserve Congress focused the JT3D re-engining program on the KC-135s in the Air National Guard and the Air Force Reserve. The Guard and Reserve, however, did not maintain backup aircraft in their inventory. Thus, unless JT3D re-engining continued, there would have been no backup KC-135E aircraft. Alternative Approaches for Tanker Re-engining CBO examined three approaches for increasing the Air Force’s tanker capability: Continue the current CFM56 re-engining program at the maximum rate of six per month, for a total of 334 additional re-engined KC-135R aircraft. Continue the CFM56 re-engining program at a reduced maximum rate of four per month, for a total of 334 re-engined KC-135R aircraft. Combine the JT3D and CFM56 re-engining programs at a maximum rate of six per month, for a total of 334 additional re-engined aircraft—166 KC-135Es and 168 KC-135Rs. Pros and Cons of Different Approaches The combined JT3D/CFM56 approach offered more capability in the near to mid term (through 1992). Initially, this approach also cost significantly less ($4.3 billion over 4 years as opposed to $7.1 and $7.4 billion for the 6 and 4 per month CFM56 approaches, respectively). Also, having the CFM56 and JT3D programs ongoing could offer some competitive pressure to keep costs down. However, in the long run, the combined alternative would provide about 50 fewer KC-135A equivalents than either approach involving the pure CFM56. Also, the age of the JT3D engines and variability among them might have made them more difficult and costly to maintain. The pure CFM56 re-engining approaches also offered advantages. The CFM56 was a brand-new engine, making it inherently more capable. Moreover, in the long run, the CFM56 might have cost no more than the combined JT3D/CFM56 approach. Air Force estimates of LLCs suggested that, over 20 years, the cost would have been about the same. Finally, the CFM56 was quiet and met the noise and emissions standards that applied to nonmilitary aircraft.