Quads vs. Helicopters
Velos UAVs are simple to fly while offering more reliability, longer flight time and more payload capacity than any quad or multicopter in the same class today. Velos UAVs are more stable in bad weather, achieve higher cruising speeds, and have higher ascend and descend speeds, which results in longer flight times.
Why is helicopter technology superior?
Lift is proportional to wing area. Considering that the outer 30% part of a blade–rotor–propeller produces more than 60% of the total lift it is clear that as the propeller gets smaller we will have to use more propellers rotating at much higher RPMs to compensate for the reduced wing area and produce the same thrust. The efficiency goes down and energy is wasted in rotating many small props at high speeds. Also according to the Reynold numbers, the larger a wing–rotor–propeller gets, the more the lift coefficient increases. In other words, you get more lift for less energy. So you can fly more with the same payload or have heavier payloads in the same flight time.
Additional reasons helicopters are superior to quads include:
FLIGHTS UNDER WINDY CONDITIONS
Helicopters are much more stable in windy conditions compared to multicopters. The reason for that is that the angle of attack of the helicopter blades is constantly changing, adapting to the environmental conditions instantly, compensating for any external forces, and keeping the ship in complete balance.
MORE PAYLOAD
Helicopter drones are capable of carrying heavier payloads and staying in the air for long flying times, unlike multirotor drones that can carry light payloads with reduced flight times. This capability combined with fast cruising speeds and hovering ability makes helicopter drones a one-way option for the execution of demanding missions such as Search and Rescue.
HIGHER CRUISING SPEED
As the angle of attack of the helicopter blades is constantly changing helicopters can fly with much higher cruising speeds while saving energy in comparison with the multicopters that spend more to fly fast. So even if a helicopter and a multicopter have the same flight time with the helicopter you can travel much longer distances, cover more area and finish your mission in less time or do more at the same time.
ACCURATE FLIGHT PLANS
Helicopter drones can do more accurate and efficient flight routes than airplane drones even if flight routes include square, triangle or any polygonal paths. This results in a fast and accurate mission implementation with minimum energy consumption.
DESCEND AS FAST AS THEY ASCEND
Another benefit of the helicopters is their ability to descend at the same rate they ascend by varying the pitch of the blades. This is not possible with multicopters as they are using fixed pitch propellers and the only way to descend is to reduce rpms. Doing so you lose stability and you can only descend at very slow rates.
EASY TO TRANSPORT AND DEPLOY
When considering a versatile UAV solution that is easy to transport and store, you will come to the following conclusion: Helicopter UAVs require less space for transportation or storage than the comparable multicopters or airplane drones. Furthermore, the deployment process of a helicopter drone is so easy and fast, instead of assembling wings or propellers all you have to do is to mount the main blades, and the helicopter UAV is ready for the next mission.