In January of this year, the Air Mule took its first flight: a short, wobbly hop from the side of a parking lot to a space a modest distance away. On Tuesday, Air Mule makers Urban Aeronautics announced two major feats for the Air Mule program. The first is a new name: Cormorant, after the family of coastal birds. The second is a full, autonomous flight on a preplanned route.
Urban Aeronautics’ Fancraft
Three of the core aerodynamic breakthroughs are:
A “Vane Control System” (VCS), that is comprised of a cascade of vanes at both the inlet and outlet of the ducts that can be deflected either in unison (top and bottom) or differentially to generate either pure side force or pure rolling moment. The ducts (front and back) can also be deflected differentially to generate yaw. The bottom line is that the VCS generates 6 degrees of freedom entirely independent of one another and, for the first time, we have a vehicle that can move sideways without the need to roll and vice versa. In addition, the VCS generates such a great amount of control power that the vehicle can withstand gusts of up to 40 knots.
A set of louvers or similar devices at the front of the forward duct and rear of the aft duct that open during forward flight to allow the incoming flow to move through the duct and thereby greatly reduce drag to enable forward speeds of up to 120 knots.
Close aerodynamic tailoring between the lift rotors and the fuselage whereby the fuselage itself functions as an airfoil and generates sufficient lift at high speed (50% of what the aircraft requires) to be able to off-load 50% of the needed lift from the rotors.
In parallel to the ‘standard’ Fancraft
High speed performance is accomplished primarily through a “stagger” built into the three main components of the vehicle: forward fan, centre fuselage and rear fan. A horizontal stabilizer is also mounted at the rear of the vehicle and canted sharply upward.
On the ground and in hover the fans are essentially horizontal to the ground. When in cruise flight the vehicle tilts forward so that the lift fans are acting partly as thrusters. Lift is distributed throughout the fuselage via a unique geometry that interacts aerodynamically both with the incoming flow and with the two fans mounted fore and aft.
The vehicle’s vane control system and other company-patented aerodynamic and flight control provisions further enhance the design with regard to safety, gust capability and noise.
Urban Aeronautics Cormorant. Formerly known as the “Air Mule,” this is a flying taxi, or maybe a future unmanned ambulance.