A2-Cal Aptos Mini (concept design)

(Image credit: A2-Cal)

Aptos Mini (concept design)
A2-Cal
Berkeley, California, USA
www.a2-cal.com

Jean-Francois Clavreul is an aircraft designer based in Berkeley, California, USA, who has been part of the teams designing the AKOYA seaplane by LISA Airplanes, the Joby S4 eVTOL by Joby Aviation and cargo UAVs by Camp6. Clavreul has designed his own aircraft, the Aptos Blue electric vertical takeoff and landing (eVTOL) aircraft for air ambulance service and won the first place at the Royal Aeronautical Society General Aviation Design Competition in 2020.

Aptos Mini autonomous air ambulance hybrid-electric VTOL concept design rotorcraft
The Aptos Mini is an autonomously piloted, one patient, air ambulance hybrid-electric VTOL concept design rotorcraft. The concept design helicopter shows the patient laying in the rotorcraft pod without a protective cover to keep the downwash of the coaxial-rotorblades off the patient. Adding a clear or opaque canopy for the patient is a possible design change if a prototype of the rotocraft is ever made.

The cruise speed has been estimated to be 100 mph (161 km/h) with an anticipated flight time of one hour. The rotorcraft has coaxial-rotorblades using at least two electric motors and is powered by a hybrid-electric power source. The maximum payload weight is projected to be 331 lb (150 kg). Coxaxial-rotorblades on a helicopter are known to have the capability of lifting heavy payloads. The fuselage is made from carbon fiber composite to give the rotorcraft a high strength to low weight ratio. For landing gear, the patient pod has fixed tricycle strut landing gear. It is unknown if the patient pod is detachable from the coaxial-rotorblade and power source assembly.

It is important to remember that all concept design aircraft specifications are estimated and can or will change as prototypes and production models are made, tested and flown with real world avionics, components and payloads.

Specifications:

• Aircraft type: Uncrewed EMS hybrid-electric VTOL concept design helicopter 
• Piloting: Autonomous piloting (this is the goal)
• Capacity: 1 patient
• Cruise speed (estimated): 100 mph (161 km/h)
  Flight time (estimated): 1 hour
  Maximum payload weight (estimated): 331 lb (150 kg)
• Propellers: 2 coaxial-rotor counterrotating rotorblades
• Electric motors: 2 electric motors
• Power source: Hybrid-electric power source
• Fuselage: Carbon fiber composite
• Landing gear: Fixed tricycle strut landing gear
• Safety features: If the power fails, the aircraft can autorotate safely to the ground. There are redundancies in critical components in the sub-systems of the aircraft providing safety through redundancy.

Related Aircraft:

• A2-Cal Aptos Blue (concept design)

Resources:

• A2-Cal website
• A2-Cal YouTube Channel
• Jean-Francois Clavreul LinkedIn
• Video: Aptos Blue, A2-Cal, Nov. 15, 2020
• Article: A2-Cal Aptos Mini, GoAERO, date unknown
• Article: Meet the Teams: Team A2-CAL, GoAERO, Mar. 20, 2025