Tuesday, September 1, 2009
Rotorcraft Report: Next Steps for Army AATE/ITEP Program
The U.S. Army has issued a Request for Information as the next phase in development of its Improved Turbine Engine Program (ITEP). The ITEP is a 3,000-shp engine program "based upon Advanced Affordable Turbine Engine (AATE) technology development," the Army stated in its RFI, issued on July 22. The ITEP is planned as a replacement for the T700-GE-701C/D engines that currently power the UH-60 Black Hawk and AH-64D Apache and date back to 1978. The engine is also used to power a wide variety of helicopters, from other U.S. military services as well as commercial and foreign military helicopters, such as the S-92, S-70, NH90 and EH101. The Army issued its initial announcement for a growth engine replacement in 1998, although launch funding did not become available until the 2007/2008 timeframe.
Two U.S. companies are competing for the ultimate production contract for the ITEP — GE, maker of the original T700/CT7 family, and the Advanced Turbine Engine Company (ATEC), a 50/50 joint venture created in 2007 between Honeywell and Pratt & Whitney to develop AATE technology. Both companies are now in the science and technology (S&T) phase of demonstrating the AATE technology for the future ITEP. ATEC designated its future ITEP engine the HPW3000, while GE is offering its GE3000.
The U.S. Army’s Aviation Applied Technology Directorate completed the Preliminary Design Review (PDR) on the engines late last year. The Detailed Design Review has also been completed and the Critical Design Review (CDR) will be conducted this December, with validation and full engine testing expected to continue through 2011. The AATE program is being conducted under a $109-million contract for each competitor.
GE stated that it had initially been selected as the winner of the AATE competition and awarded the contract. "Subsequently, the Army decided to also award a similar contract to the competition. Additionally, GE has distinguished itself by being selected for five AATE components — turbine technology ceramic matrix composites, advanced power turbine, mechanical systems, compact high-power combustor and advanced compressor," a company spokesperson said.
Full S&T development and testing for the AATE is expected to last through fiscal year 2012. The recently released Army RFI reflects that ITEP development will enter engineering manufacturing development (EMD) in FY2013 with the two contractors who will continue development of their candidate engines through preliminary flight rating test and flight demonstrations, before down selecting to contractor in FY2016.
Objectives of the new engine program are based on comparative parameters of the -701C, providing a 25 percent improvement in specific fuel consumption, a 65 percent increase in power-to-weight ratio, a 35 percent reduction in production and maintenance costs and a 20 percent increase in engine design life.
Reduction in the SFC is considered paramount, considering that under current combat conditions in Iraq and Afghanistan, the Army estimates the cost of fuel to be $30 per gallon when delivered by truck to an aviation unit 600 km (324 nm) inland, and $400 per gallon when delivered by CH-47. A 25 percent reduction in SFC equates to a 12 percent reduction in direct fuel consumption, or an estimated savings of 9.4 million gallons per year.
The Army states that the ITEP is focused on "development and qualification of a new centerline, turboshaft engine that is needed to support modernization requirements necessary to ensure the Apache and Black Hawk remain operationally effective well into the 21st century." It also noted that "additional Black Hawk lift capability is needed for hot/high operating conditions and a significant increase in aircraft mission radius capability, up to 500 km (270 nm), is desired for both the Apache and Black Hawk helicopters."
As the program transitions into EMD, based on the Army’s RFI acquisition strategy, it requires the two contractors to install and demonstrate their engine’s performance and ease of installation and integration. The primary objective is to have a drop-in configuration with minimum cost and complexity to accomplish the installation.
The HPW3000 configuration will be a two-spool engine designed for drop-in installation. It reportedly will require less power to start and reduce overall installation costs. It enables the use of a battery to start, providing the Army the option to eliminate the need for an auxiliary power unit (APU).
GE stated it could not discuss the technical aspects of the GE3000, simply that it will be a new centerline engine, able to start with or without an APU.
A lower retrofit cost is also expected, since the new engine will fit into the current mounts without a need for redesigned fittings or any fuselage changes. ATEC claims its engine will feature a 25 percent growth capability within the same installation envelope in anticipation of future helicopter performance and growth requirements, while GE simply stated that the GE3000 "is designed to meet specific requirements set forth by the Army for its future platform requirements."
ATEC also pointed out that it is a "green" engine, not only operating at a lower SFC, but producing fewer emissions, having a lower noise footprint and possessing the ability to operate on alternative fuels, to include biofuels.
Current combat assault specifications for the UH-60M Black Hawk with the T700-701D engine under 4,000-ft, 95°F conditions include a mission radius of 233 km (126 nm) with a payload capacity of 3,190 lbs at a max gross takeoff weight of 19,401 lbs. Expanding the current -701D from 2,000 to 3,000 shp would increase Black Hawk empty weight by 200 lbs, but could retain the same payload while increasing fuel consumption and reducing mission radius to 190 km (103 nm). The 3,000-shp ITEP engine will enable retention of the same max gross takeoff weight and payload, but with reduced fuel consumption that will increase the mission radius to 271 km (146 nm). An ITEP engine on the UH-60M would either extend the mission radius with an external payload of 9,000 lbs from 65 km (35 nm) to 135 km (73 nm), or would allow the ITEP engine with an improved transmission to carry a 9,000-lb payload 135 km, while the -701D-equipped UH-60M would be restricted to just over 5,000 lbs.
For the Apache powered by the -701C engine, the new ITEP engine would increase range from 260 nm (140 nm) to 325 nm (175 nm) and payload from 3,400 to 4,500 lbs.
Both competing engines are expected to exceed the Army’s requirements, as well as minimize the Army’s current T700 logistic footprint. Program development cost for the ITEP is estimated at $500 million. However, annual direct operating and support (O&S) cost savings are estimated at around $80 million per year. This includes a savings of $44 million in engine O&S costs and $9 million in fuel for the UH-60 fleet of 1,500 aircraft, and $24 million in engine O&S costs and $3 million in fuel for the AH-64 fleet of 700 aircraft. Based on those estimates, the Army’s development cost breakeven point is 6.25 years. — By Douglas W. Nelms
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