October 15, 2019 | International, Aerospace
Graham Warwick
Sikorsky is emphasizing growth capability to stay ahead of evolving threats as it unveils its offering in the U.S. Army's Future Attack Reconnaissance Aircraft (FARA) competition, the Raider-X.
The coaxial rigid-rotor compound helicopter is a development of the S-97 Raider prototype now in flight testing.
The Raider-X is about 20% larger, with a 14,000-lb. gross weight compared with 11,000 lb. for the S-97, and a 39-ft. rotor diameter compared with 34 ft. for the Raider. The Army requires a rotor diameter of no more than 40 ft. so that FARA can fly between buildings in urban combat.
The Raider-X will exceed the FARA's threshold maximum speed of 180 kt. Sikorsky is not saying how fast it will fly, but notes the S-97 has reached 215 kt., and 207 kt. in level flight—exceeding the 205 kt. target in the Army's initial capability document, says Tim Malia, director of Future Vertical Lift - Light.
The Army subsequently reduced the threshold maximum speed to enable a wider competition for the FARA program. But Malia says the greater speed and payload capability of Sikorsky's X2 coaxial rigid-rotor compound configuration compared with a conventional helicopter provides growth capacity.
“We looked at a single main rotor helicopter for FARA, but it would be minimally compliant in the early 2020s. We need to be able to stay ahead of the threat into the 2030s and 2040s,” he says.
Bell is proposing a winged, single-main-rotor helicopter for FARA, while AVX Aircraft is offering a coaxial-rotor, ducted-fan compound. Boeing and Karem Aircraft have yet to unveil their concepts.
“Single main rotor will not be able to keep up. It's already tapped out meeting the minimal FARA requirements. It does not have the ability to grow capability over time,” Malia says. “We didn't want to pull out all the stops to be minimally compliant when we had X2 able to carry more payload and go faster.”
The Raider-X has four-blade rotors and a pusher propulsor. The coaxial rotors generate lift only on the advancing sides, eliminating retreating-blade stall and enabling higher speed. At high speed, 90% of the engine power goes to the propulsor, says Bill Fell, senior experimental test pilot. The propulsor is declutched at low speed to reduce noise.
The Raider-X closely resembles the S-97 prototype, with side-by-side seating. Compared with tandem seating, this improves crew coordination and situational awareness, Malia says. “And we can do it aerodynamically because of the robust performance inherent in X2. We are not trying to get out every last ounce of drag.”
Behind the cockpit is a large internal weapons bay. Internal carriage of missiles and unmanned aircraft—which the Army calls air-launched effects (ALE)—is a FARA requirement, but Malia says the cabin-like volume of Raider-X's bay provides growth space for future, larger systems. “The minimum threshold works now, but what if in 2030 there is a new ALE that can be decisive, but can't be carried?” he asks.
The Raider-X is powered by a single 3,000-shp-class General Electric T901 turboshaft—government-furnished equipment to all FARA bidders. “We do not have an additional engine to increase speed,” Malia says, referring to the supplemental power unit in Bell's 360 Invictus. This augments power from the single T901 to give the single-main-rotor, tandem-seat Invictus a 185-kt. maximum speed.
“We use the power available and have a solid design built around it,” he says. “The T901 provides speeds out of the chute in excess of requirements and, as it improves, we can take direct benefit. We have a growth path to additional speed and payload as the T901 power increases.”
Sikorsky is using the industry-funded S-97 prototype to reduce risk for its FARA bid, conducting flight testing to validate design models and optimize the Raider-X. This includes flying new rotor blades designed to reduce drag and vibration. “We are getting exactly the results the models said,” Malia says.
With two rotor systems and a propulsor, Sikorsky is paying close attention to the Raider-X's cost. “We have done a complete affordability analysis and design to cost. We are extremely confident we will come in under the cost goal,” he says.
Several divisions of parent company Lockheed Martin are part of Sikorsky's FARA team, Malia says, including Aeronautics, Missiles and Fire Control and Rotary and Mission Systems. Swift Engineering will build the airframe if Sikorsky wins one of two FARA competitive prototype contracts scheduled to be awarded in March 2020. The Army flyoff is planned for 2023, with the first unit to be equipped by 2028.
“There is a critical cap in vertical lift, in attack/reconnaissance, and that gap is really impactful to the Army in the 2020s, ‘30s, ‘40s, even ‘50s. So there is a need for a long-term solution,” Malia says. “The threat is projected to evolve rapidly, so we require significant capability growth on our side to stay ahead. Raider-X can provide an asymmetric advantage in the 2030s-50s.”
https://aviationweek.com/defense/sikorsky-unveils-raider-x-proposal-fara-armed-scout
July 26, 2022 | International, C4ISR
President Joe Biden met virtually on Monday with the chief executive of Lockheed Martin and other companies to spur forward a bill to boost semiconductor production in the United States.
July 7, 2020 | International, Aerospace, Land
Jen Judson WASHINGTON — The Army is on a path to use space sensors to help its artillery see and shoot well beyond current capability. The service has already wrapped up an effort to achieve this capability, which took place in Europe in February and March, Gen. Mike Murray, Army Futures Command commander, told reporters in a media call. Murray was discussing how Army modernization would proceed despite COVID-19 social isolation measures in April. The Army will continue to build upon these early successes tapping into space assets to help guns on the ground hit long-range targets, an Army spokesperson told Defense News in a written statement. Conducted through Futures Command's cross functional team in charge of Assured Position, Navigation and Timing (A-PNT), the service was able to link space sensors with shooters in live-fire demonstrations in Grafenwoehr, Germany, on three separate occasions with the latest on March 23, the spokesperson wrote. Over the course of the demonstrations, the team “successfully sensed and hit targets at ranges beyond line of sight using satellite capabilities that have not been accessible to ground forces until now,” the spokesperson said. The exercise showed the “Army's ability to engage and defeat time sensitive targets with timely and accurate fires anywhere on the battlefield.” Tapping sensors that can help guide missiles and munitions to targets deep into the battlefield is critical to the Army's future long-range precision fires capability and key to operating across multiple domains. But achieving such distances requires connecting sensors and shooters that have never worked together before Long-Range Precision Fires (LRPF) is the Army's top modernization priority as it plays a critical role in the future battlefield and will be a centerpiece in the service's future Multi-Domain Operations doctrine currently in development. The LRPT cross functional team will continue to push the capabilities to far greater ranges than previously capable or than those distances previously allowed prior to the United States' withdrawal from the Intermediate-Range Nuclear Forces Treaty in 2019. During the initial live-fire demonstrations, a unit conducted an operation using the weapons and ammunition associated with their mission — in this case the Army integrated the capability with the Multiple Launch Rocket System (MLRS) and the M777 howitzer. The demonstrations used high explosive rounds equipped with a precision guidance kit fuze fired from the M777 howitzer or MRLS launcher. The Advanced Miniaturized Data Acquisition and Dissemination Vehicle accessed various sensors and target data was transmitted through the Joint Automated Deep Operations Coordination System and the Advanced Field Artillery Database System for the technical and tactical fire direction processes, the spokesperson detailed. The demonstrations gave “insight” into current capabilities “and their ability to link in novel ways to provide a capability down to the division operational level of combat,” the Army spokesperson said. Originally, pre-pandemic, the Army had planned to work on the capability throughout the scaled-back Defender Europe 2020 exercise using space-based sensors to pursue deep targets that “have not been responsive to ground forces until now,” according to the spokesperson. The APNT team will build upon the demonstrations by finding ways to reduce the sensor-to-shooter timeline to meet capability needs in the future anticipated operating environments. Ultimately, the Army will integrate the capability into the future Extended Range Cannon and a “full suite of Army fires platforms.” The ERCA cannon has already reached ranges of roughly 40 miles in recent tests at Yuma Proving Ground, Arizona. The service also plans to begin integrating with aviation platforms, the spokesperson said. The demonstrations are feeding into a “targeting process multi-domain operational strategy,” according to the spokesperson. The Army also plans to work on an architecture that connects both kinetic and non-kinetic assets from across joint, interagency and multinational partners. https://www.c4isrnet.com/2020/07/06/army-on-path-to-use-space-sensors-to-help-guns-on-the-ground-see-farther/
August 29, 2018 | International, C4ISR
By: Kelsey Atherton The ocean hides what it contains, and it is in that hiding that submarines have their power. Lurking under seas, at first with just enough capability for an attack run and now with the ability to lurk for months at a time, submarines remain power out of reach, unseen until engaged in combat or resupplying in a friendly port. That stealth comes at a cost, however, besides the simple perils of existing underwater. When submerged, submarines are more or less on their own until they resurface again, since radio waves do not travel well through seawater. Or they are for now. New research by MIT, presented at a conference in late August, devised a way for submerged submarines to communicate wirelessly with people on the surface by combining hydroacoustics and acoustic radars. Presently, submarines communicate either across normal radio frequencies when surfaced or through hydroacoustic signals and listening posts underwater that can transmit the messages back to counterparts on shore. Very and extremely low-frequency radio waves can be transmitted in a way that submarines can listen to below the surface, but it's a one-way form of communication, from stations on land to submarines. To get something responsive, with the flexibility to communicate away from static seabed hydrophones, needs something else. Specifically, it needs a way to combine hydroacoustic transmission from the submarine through water that can then be converted into a useful data. “We present a new communication technology, translational acoustic-RF communication (TARF),” write paper authors Francesco Tonolini and Fadel Adib of the MIT Media Lab. “TARF enables underwater nodes to directly communicate with airborne nodes by transmitting standard acoustic signals. TARF exploits the fact that underwater acoustic signals travel as pressure waves, and that these waves cause displacements of the water surface when they impinge on the water-air boundary. To decode the transmitted signals, TARF leverages an airborne radar which measures and decodes these surface displacements.” In testing, they demonstrated that the communication technique can transfer data at standard underwater bitrates up to 400bps, and even do so with surface waves 6.3 inches crest-to-crest, or 100,000 times larger than the surface perturbations made by the acoustic transmitter. Right now, this communication is one-way. While the signal transmitted up from the water produces useful information at the boundary with the air, a signal transmitted through the air downwards would disintegrate on integration with water. This one-way is distinct from previous forms of communication with submarines, however, as it lets the submarine talk without revealing its position to surface sensors. Despite the limitations, and the earlierness of the research, Tonolini and Adlib see a bright future for the technology, as a way to enable a host of new technology in machines. The technology, they write, can enable “many applications including submarine-to-drone communication, deep-sea exploration, and subsea IoT (Internet of Things). https://www.c4isrnet.com/c2-comms/2018/08/28/mit-discovers-way-for-submarines-to-talk-to-drones