DDRH and DDVL
These concept hybrid-electric VTOL aircraft, the DDRH and the DDVL, are the creations of Gino d’Ignazio who appears to be based in Italy. He uses 3D-design software to create his 3D images of his hybrid VTOL aircraft. His interest to design electric/hybrid aircraft came from being a helicopter pilot, wanting to improve upon helicopters and then understanding why aircraft designers use Auxiliary Power Units (APU) in jetliners. (APUs are also found in some helicopters.)
A little about APUs. When a jetliner is at the gate of an airport, with their engines off, how do they keep all the electrical systems powered on? The Auxiliary Power Unit. The APU is a turbine engine connected to a generator which creates enough electricity power for its electrical needs for the entire aircraft. The APU is typically powered when the aircraft is parked and when the main jet engines are turned off but can even be used for additional electrical power during flight operations. When the aircraft is at a gate, the APU powers the cockpit instruments, lighting, flight attendant ovens/coffee makers, the air conditioning system and other electrical systems. Typically, the APU is located in the tail of the jet. You’ll notice that on most jets, there is an exhaust port in the tail of the jetliner. In Google Images, type “jetliner apu”, “jetliner apu exhaust port”, “airliner apu” or “airliner apu exhaust port” (without quotes) and you’ll see pictures of the APU exhaust port. People have even made graphics of the APU and note on the graphic how shocked they are that there is an extra engine on jetliners.
Gino d’Ignazio, back in 1995-1996, when flying commercial jet airliners, was thinking about how APUs are used to power the aircraft while parked at gates with their engines shut down. At the time Gino was a helicopter pilot and had been working several ideas for an electrically powered helicopter with ducted rotors but was unable to solve the technical issues to accomplish his goal.
After realizing how jetliners had been using APUs for years to create power for the aircraft, he realized his technical issues were beginning to be solved. Use a turbine engine to power the electric engines to power the aircraft’s ducted propellers and the rest of the aircraft’s systems such as instruments and its ventilation system.
He liked this idea because an aircraft would not have a heavy transmission, no heavy shafts would go to the tail rotors, maintenance would be reduced and the aircraft would be quieter. A less complex aircraft due to simpler systems, he surmised, would increase the efficiency of the aircraft and become a better and safer aircraft. The DDRH and DDVL are his first and second designs for what he calls a hybrid ducted helicopter and what we now call a hybrid-electric ducted VTOL aircraft.
The DDRH and DDVL are 1 passenger aircraft with amble space in the cockpit for the pilot, with a large front window and side windows which form an L shape so that visibility is not restricted when looking downward to the left or right. He envisioned glass cockpits even in 1996 because he thought that too many analog instruments can make it confusing for any pilot. The small turbine engine would be capable of generating a power of about 240 hp (178Kw) of output, powering 2 sets of ducted propellers, each set having dual electric motors and five propellers.
He envisions an Automatic Flight Control system capable managing each of the rotors independently, modifying both rotor rpm as well the pitch angle of the blades, in order to guarantee the stability of the aircraftin any flight condition.
This concept aircraft lead to the design of what he calls his most important concept aircraft called the CellCraft. Note: To the best of our knowledge, scale or full-sized test beds or prototypes have never been created for this aircraft.
Graphic credit: Gino d’Ignazio