When we last heard about the Cormorant UAV (Unmanned Aerial Vehicle), it had made its first untethered autonomous flight. Now, the VTOL (Vertical Takeoff and Landing) aircraft has performed a small-scale mission for prospective buyers.
Designed by Israeli firm Tactical Robotics, the Cormorant is designed to fly either autonomously or by remote control, delivering troops, civilian passengers or other cargo within tight quarters where helicopters with exposed rotor blades just can't go. Vertical lift is provided by internal rotor blades contained within its body, while horizontal thrust comes from two shrouded rear propellers.
On May 7th at the Megiddo Airfield in Northern Israel, it was used to perform a "mission representative" demonstration for members of the Israel Defense Forces, which is currently the lead customer for the aircraft.
The demo consisted of having the Cormorant take off with a load of cargo, follow a predetermined flight path to a specified point of delivery, drop off that cargo and have it replaced with a medical training mannequin simulating a casualty, and then fly back to its point of origin. On the way back, an onboard system allowed for two-way video communication between a team on the ground and the "patient."
Although a human crew was responsible for off-loading the cargo and putting the mannequin on board, the Cormorant itself performed the whole exercise in autonomous mode. According to the company, the aircraft is currently "the only UAS [Unmanned Aerial System] recognized by NATO to fulfill both cargo delivery and CasEvac [Casualty Evacuation] missions."
Source: Tactical Robotics
That's just how ducted fans sound.