Aircraft

Pterodynamics scales up its remarkable dihedral Transwing eVTOL

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The Transwing design offers this compact and stable VTOL and hover mode, with an exceptionally large wingspan in cruise mode for outstanding efficiency
Pterodynamics
The Transwing design offers this compact and stable VTOL and hover mode, with an exceptionally large wingspan in cruise mode for outstanding efficiency
Pterodynamics
The Transwing design looks particularly odd in mid-transition
Pterodynamics
The Transwing aircraft's wings rotate as they fold
Pterodynamics
This design is exceptionally compact in its ready-to-fly VTOL configuration
Pterodynamics
In cruise flight, it looks like a regular plane
Pterodynamics
A tiny ground footprint makes this thing very easy to transport, store, and land
Pterodynamics
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Fresh video shows that one of the most fascinating eVTOL aircraft designs we've seen is now flying at larger scale. The Transwing platform uses a unique dihedral folding wing system to move between hover and cruise modes, unlocking huge advantages.

Transitioning electric VTOL aircraft can take off and land more or less like multicopter drones, but then cruise efficiently in forward flight supported by wing lift. There are literally hundreds of companies racing to bring different designs to market, and they all have to deal with the same set of problems.

The most efficient winged flight requires large, wide wings, but large wings are a headache when you're trying to land, and take up a lot of space on the ground. The simplest way to handle both vertical and cruise flight is to run separate propellers for each mode, but then you add parasitic drag and weight.

The Transwing aircraft's wings rotate as they fold
Pterodynamics

Pterodynamics – as we've covered before – says it's created an exceptionally efficient eVTOL airframe that's also exceptionally small on a landing pad, and mechanically quite simple.

This unique and patented design looks just like a plane in forward flight, with props distributed along its wings. But when it's time to land, the wings fold back, ending up stowed against the sides of the fuselage.

The key here is the dihedral hinges upon which the wings rotate; the wings tilt as they fold, so by the time they're resting back against the body of the aircraft, they're facing upward, along with the propellers. The entire transition is "aerodynamically benign," simple and smooth, and it's driven mechanically by little struts extending from the fuselage, on a linear actuator.

In cruise flight, it looks like a regular plane
Pterodynamics

As a result, these things can run significantly wider wings than any other eVTOL design where ground space or helipad access is a concern. And for portable drone-style applications, they can sit in a compact box, completely ready to fly.

Pterodynamics has built its X-P4 prototype with a 4 m (13.1 ft) wingspan, and a fuselage about 2 m (6.6 ft) long. It runs only two props in forward flight according to Unmanned Systems Technology magazine, allowing the other two to passively fold back against their nacelles until they're needed for a vertical landing.

It's been undergoing testing with the US Navy as a ship-to-shore logistics platform, a job in which it could ferry roughly a cubic foot of cargo, held within its fuselage, vastly cheaper than the current solution – which is apparently to fly things out to Navy ships on Black Hawk helicopters or V-22 Osprey VTOL aircraft.

This design is exceptionally compact in its ready-to-fly VTOL configuration
Pterodynamics

But the concept is capable of scaling much larger, up to eVTOL air taxi size and beyond. Indeed, a Transwing design could potentially fly 10 or more people from rooftop to rooftop, while fitting on the same helipad that a five-seat Joby or seven-seat Lilium might use.

And with the ability to run very large wings, as well as the capability to start transitioning toward cruise flight almost immediately upon takeoff, it promises to be one of the most efficient eVTOL designs around, capable of squeezing more range out of a battery than competing designs.

Check out the X-P4 drone in action in the excellent video below. This is a very promising idea and we look forward to seeing where it ends up going!

Source: Pterodynamics

View gallery - 6 images
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13 comments
EJ222
Wow... that feels like the end-all design. The mechanism is so simple and lightweight, but "ideal" in either configuration.

Seems like militaries would salivate over this.

They need some creativity on the propeller to make it smaller in forward flight and bigger for hovering, but that's about it.
McDesign
So nice!
Joy Parr
This is the most effective design I've seen so far. It looks like a winner over Joby and Lilium.
riczero-b
In transition, all the weight and acceleration / aerodynamic forces seem to be borne by two slender looking spars. It obviously works as shown, but will it scale up to passenger capable size ?
Smokey_Bear
Damn, I read some comments and everyone was talking about the transition...it didn't disappoint. Beautiful, super smooth, genius design.
Can't believe no one has done this before...they got some talented people there.
mark41
If the outer two rotors are only used during takeoff/landing, why pivot them?
The two outer rotors could be removed from the wings and placed vertically in the fuselage, one in the forward fuselage and one in the rear fuselage. They could possibly be lift fans instead of propellers. Opening doors for the lift fans would smooth aerodynamics for forward flight.
windykites
This is an ingenious design. The only thing that worries me is the wing hinges.
is it easier to have swivelling engine nacelles?
Mark 41 has some good comments.
Laszlo KRUPPA
Agree with many of the commenters: genius design! Problem of transitioning for the tiltrotor/tiltwing family can be checked out for good: this concept seems close to unbeatable.

Want to reinforce EJ222. Now that the airframe concept has been fixed ( 😊 ), it is time to shift focus on the propellers.

It is known the tiltrotor/tiltwing aircraft still have their unsolved rotor/propeller dilemma: shall the propellers serve more hover or more the forward flight? Excellent top speed values as a rule must be reduced to allow desired vertical lift/hover performance. This contradiction can finally be solved when a similar genius concept arrives that will allow rotors and propellers have the VARIABLE BLADE TWIST feature.

WONKY KLERKY
The case for separate landing gear:
Sudden drop, from even short height, at landing would = poorly hinge mech' (at the least).
Unsold
They're gonna sell a LOT of those. Makes you wonder how well it would scale up for passengers...