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The CLA Light (foreground) is a clean-sheet unmanned aircraft system; the optionally piloted CLA Heavy is a retrofitted nine-passenger aircraft.
U.S. startup Whisper Aero has unveiled plans to develop a family of hybrid-electric autonomous cargo aircraft that are planned to be prototyped over the next three years with funding from the U.S. Air Force.
Unveiled during the Special Operations Week conference in Tampa, Florida, the Collaborative Logistics Aircraft (CLA) family comprises the clean-sheet Group 3 uncrewed CLA Light, with a 500-lb. payload, and the Group 5 optionally piloted CLA Heavy, a retrofitted nine-passenger aircraft able to carry 3,000 lb. of cargo.
Design and manufacture of prototypes is to be supported by funding from the Air Force through the Strategic Funding Increase and Operational Energy Capability Improvement Fund programs. The CLA Light is expected to fly in 2027 and the CLA Heavy in 2028, Whisper COO Ian Villa says.
Both aircraft are propelled by Whisper Aero ultraquiet eQ250 electric ducted fans, powered by a turbogenerator and batteries. The fans are arrayed to blow over the wing to increase lift coefficient–an arrangement the startup calls JetFoil–that enables short-field capability. Whisper says the JetFoil blown wing can achieve lift coefficients as high as 14, an increase of eight-10 times versus an unpowered airfoil, enabling short takeoffs and landings from austere and degraded runways–particularly airstrips left over from World War II in the Pacific and other theaters.
The startup is the prime contractor for the prototyping program, but will work with unnamed airframe and turbogenerator partners to develop the aircraft. Whisper plans to transition to being the propulsion system supplier if the effort transitions to a program of record, CEO Mark Moore says.
The CLA Light has a 40-kW powerplant that drives an array of 12 eQ250s on the wing leading edge, each producing 80 lb. of static thrust. The 1,300-lb. gross-weight aircraft can take off with a 50 ft. ground roll and has a dash speed of 175 kt. (201.3 mph) and a range exceeding 200 nm carrying a 500 lb. payload.
The 10,140 lb. CLA Heavy has a 600-kW powerplant driving 30 ducted fans on the leading edge of a new 50-ft. span that will be retrofitted to an existing nine-passenger airframe. The aircraft is capable of taking off with a 300-ft. ground roll and cruising at 250 kt. for 800 nm with the maximum 3,000 lb. payload.
Whisper points to several design aspects suited to the distributed logistics mission in contested environments, particularly in the Indo-Pacific theater. One is hybrid propulsion, which reduces fuel consumption, freeing up fuel for combat aircraft while avoiding reliance on charging infrastructure. Another is speed, enabled by the ducted fans, which is higher than for some autonomous logistics aircraft, as well as ferry range coupled with autonomous flight capability.
With no payload, the CLA Light will be able to self-deploy more than 2,000 nm and the CLA Heavy 3,000 nm. “Without the need for a pilot on board, these aircraft are designed to be more affordable and attritable,” Whisper states. “They can reposition themselves with greater fuel efficiency, prioritizing energy needs for other aircraft in the fleet.”
Development of the CLA family will begin with flight tests of Whisper’s Ultralight, an Aeriane Swift3 glider equipped with two battery-powered eQ250 ducted fans. The startup plans flight tests in 2026 with the Air Force Test Center at White Sands Missile Range’s Acoustic Range Complex in New Mexico.
“The glider is a very intentional first part of the CLA maturation. Ultralight allows us to get flight time on our eQ250s. Once we have actual flight test data from those flights, that gives us confidence to start putting those 80 lb.-thrust propulsors on other platforms,” says Villa, noting that Whisper is taking a crawl-walk-run approach to development.
The startup has built subscale JetFoil arrays and is starting to work on a representative full-scale wing section with an array of eQ250s for testing in the next few months. “We will have the flight-test data as a crawl, then integrate them into the JetFoil array as a walk. That then gives us confidence, as we start to fly the CLA Light, to expand the array and put that onto the CLA Heavy,” Villa says.
While the CLAs have arrays of multiple propulsors, Whisper declares the overall propulsion system is less complex and easier to maintain than conventional turbine engines because of the minimal part count in the air-cooled eQ250s. The ducted fans will be line-replaceable units that can easily and quickly be swapped out in the field, Moore says.
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