Aircraft

Autonomous Flight unveils six-seat eVTOL tricopter air shuttle

Autonomous Flight unveils six-...
The Y6S Plus, a six-seat eVTOL air taxi concept from the UK's Autonomous Flight
The Y6S Plus, a six-seat eVTOL air taxi concept from the UK's Autonomous Flight
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The Y6S Plus, a six-seat eVTOL air taxi concept from the UK's Autonomous Flight
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The Y6S Plus, a six-seat eVTOL air taxi concept from the UK's Autonomous Flight
The Y6S Plus is all cabin, seating six
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The Y6S Plus is all cabin, seating six
A unique tricopter layout with coaxial rotors
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A unique tricopter layout with coaxial rotors
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UK company Autonomous Flight has been working on eVTOL concepts for some years now, with a full-scale airframe of its two-seat Y6S already built and small-scale prototypes already flight-tested and capable of transitioning from VTOL hover into horizontal flight. Now the company has revealed a six-seat air taxi – or perhaps air shuttle is a better way to describe it – called the Y6S Plus.

In the burgeoning ranks of companies working to build electric VTOL aircraft, we haven't seen a propulsion arrangement quite like this before. Autonomous Flight has gone for a tricopter layout, with two large coaxial rotors at the ends of the front canard wings, far enough away that they won't affect airflow over the wings, and a third coaxial rotor mounted at the rear of the aircraft, behind the large main wing.

Tricopters are relatively rare at the small-scale hobby drone end of the market. Here, they offer a weight advantage due to one less arm, motor and prop assembly, but in order to maintain yaw control they need to include a servo motor to tilt the rear prop. The coaxial rotors on the Y6S Plus remove the need for this rotor tilt, but it's still hard to figure out why the designers didn't go for two props at the back and a more traditional quadcopter design. Perhaps to reduce drag in forward flight once the rear props are switched off.

It certainly keeps the look fairly tidy, but one does have to wonder how much stability and control authority it'll allow with only three lift points. The front two rotors tilt forward once the aircraft's off the ground, bringing it to an efficient, winged horizontal flight mode that's good for cruise speeds around 125 mph (200 km/h).

A unique tricopter layout with coaxial rotors
A unique tricopter layout with coaxial rotors

Flying on lithium batteries, the range will be in the region of 80 miles (130 km), so it's certainly no long-hauler, and the use of landing skids rather than wheels suggests it'll be incapable of more efficient conventional takeoff and landing where the opportunity is available.

Autonomous Flight founder Martin Warner told Future Flight he doesn't expect on-call air taxi operations to be viable for at least 15 years – hence the oversized six-seat cabin. Early eVTOL operations, he feels, will work best as scheduled point-to-point shuttle services, and thus the more seats, the merrier for the operator's bottom line.

The short range offered by current lithium batteries can be less of an issue if these things are flying between friendly vertiports in a predictable fashion rather than responding to customer demand in real time; Warner is making the large battery packs swappable to keep these birds in the air and making money.

The Y6S Plus is all cabin, seating six
The Y6S Plus is all cabin, seating six

And despite the business name, the initial aircraft will indeed be piloted – not because it won't be able to fly itself, more because Warner anticipates that regulatory bodies will take a lot longer to permit it. You've got to feel for the pilots; imagine studying up, getting your eVTOL license and then interviewing for a pilot job at Autonomous Flight; I wouldn't be signing up for a mortgage on that gig.

Another one to watch as the air taxi market continues to expand and evolve.

Source: Autonomous Flight

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11 comments
Towerman
I love it ! The First serious Tri-Copter entry and it looks Great !
kvncloete
Would it be possible to have a parachute safety system for a vehicle this size in case of motor failure?
Could a hybrid fuel/electric system be used to increase salability?
Arcticshade
Nice to not needing a servo for tail control ! The wonders of counter rotating designs ! Another benefit is a smaller footprint with only 1 rotor at the rear.
Stability ? Well model Tricopters fly surprisingly stable, so can't see why it would not work, and at speed the rear wing would be an added benefit towards that end. (however even without wings tricopters do fly stable in the model world)

Also once you gain speed with the craft tilted forward, CG wil be concentrated more over the 2 front motors (but again tricopters do fly stable in the model world without wings) So i see the wings being an efficiency benefit while battery fuel cell tech is evolving. (but the wings on this machine do look compact and blends in nicely with the overall design of the craft) So i would keep it just because it compliments the looks of the machine ! Each machine is different, with VTOLS like Joby, Skai, Cityhawk, i would not want them to have wings as they look perfect without them. All we need is to extend range, fuel cell technology by them and toyota is being developed as we speak, so this should come in reasonable time we hope !
Towerman
@kvncloete
its an old question, parachute is not needed it has redundant motors, works just like any redundancy on any aircraft ie for example king air any boeing multi engine, any airbus etc. except for the fact that the electric motors is more reliable, so its redundancy is better than ice technology. Fuel cell tech is being worked on for long range, but not needed in the beginning 20-40min hops will be enough for short hops to start with.
Laszlo KRUPPA
Tricopter design holds the advantage of using higher diameter rotors for greater efficiency/battery life/flight duration. It is a pity the actual contra rotating propeller technology is destroying that option – obviously as a bargain to achieve a better cruising speed while keeping the necessary takeoff/lifting performance.

A newly proposed propeller technology suits the tricopter design optimally. It can provide both higher efficiency and a much better flight envelope. And, important in urban environment, a silent operation. Concept is ready for prototyping. Working name is Stallfree technology.

riczero-b
As kvncloete says it would sell better with ballistic recovery to help with the dead zone. I believe electric aero motors are very quick to stop so the rear rotors shouldn't need to be jettisoned.
guzmanchinky
I agree, these machines are perfect for a ballistic parachute, which up until now could not be fitted to a similar sized helicopter. They provide that last chance in case of mid air collision, etc. I had one on my aircraft for many years and loved having that red handle in the cockpit. Can't wait to see models with twice the range, which will be coming soon.
mediabeing
I'm not really going to like any of the electric eVTOL prop vehicles until all props are inside prop guards.
guzmanchinky
mediabeing why not? Current helicopters and small aircraft don't have those protections and rarely cause injury, and those can't be stopped in a second the way electric motors can be.
Towerman
EFATO on standard aircraft is a hit or miss, ballistic parachutes is not really needed, you have 2 insanely reliable brushless motors per arm. We are not talking ICE prone failure mechanics.
For those hypocritically scared, take off over water, until you realize it's not needed.

Prop aircraft have never had any "cages" around them and they are certified and the props sometimes are much bigger than EVTOL's Those that are cage are from the fenstron variety, and that is useless.

The other day a dear friend lost his hand, literally it was as if he placed his hand in a blender, mins meat by getting his hand sucked into a gazelle fenstron tail while troubleshooting for vibration. So much for dumb cages... And as been mentioned a million times, electric props stop instantly, NO NEED FOR STUPID, DRAG INDUCED WEIGHT HOGGING CAGES EVER.