Today Alef, a startup in e-VTOL aviation, revealed their full scale prototypes and production mock-up for a new class of flying vehicle they say is the first true flying car. Almost all other of the hundreds of e-VTOL startups don’t have the ability to drive on streets as well as fly, fitting in ordinary parking spaces, so while they may be called flying cars they don’t have that combination which matches the public’s conception of what such a vehicle is.
Disclaimer: I’ve been following Alef since being an early advisor back in 2018, though I have no financial interest in the company.
There’s a lot to unpack about Alef’s design:
- What does their vehicle look like and what will its cost and specs be?
- How they make a vehicle which can fit in the form factor of a traditional car, yet do vertical take-off and transition to horizontal fixed-wing flight?
- What are the trade-offs between this approach, other approaches with wheels, and the larger set of vehicles which only move in the air, not on the ground?
Vehicle Design
Alef Founder/CEO Jim Dukhovny unveils a non-flying mock up of the Alef flying car form factor
The vehicle consists of a passenger compartment inside a box-wing biplane frame. The biplane box is the outside shell of the car form factor. There is no bottom, other than structural elements, and the top is a mesh to protect people from the blades of the 8 rotors which are inside the box. Also at the center of the box is a 2-seat passenger compartment, which is articulated so it can rotate with 2 degrees of freedom.
The vehicle also features 4 wheels with hub motors (the mock-up has standard car wheels but the eventual vehicle will probably have smaller and lighter wheels.) The initial vehicle will be expensive at $300,000 and be battery-electric with a flying range of around 110 miles. Alef plans to ship that vehicle in 2025, but in the 2030s they plan to make a $35,000 vehicle once they go to scale.
How does that small form factor take off and transition?
The Alef is a transitioning vehicle, which takes off and lands like a multirotor drone, but quickly transitions to horizontal fixed-wing flight, which is much more efficient. In order to get significant range in an aircraft, you need to do this transition. Many of vehicle designs use things like tilting wings or tilting rotors to make the transition. Tilting rotors have famously been the source of disasters for the Marine Corps Osprey, but they are the most basic approach, so still popular.
The Alef transitions by rotating the vehicle 90 degrees. It tilts on its side and becomes a box-wing biplane. Biplanes were popular in the early days of flight because they allowed greater wing strength before people figure out how to make strong wide wings. Strong wide wings are superior, but they are also large. Some of the other “flying car” designs have single fixed wings which unfold in order to get sufficient wing surface.
The Opener Blackfly is a real flying vehicle which also tilts the entire vehicle. The pilot lies on her back before takeoff, but then it angles to a more comfortable position with two fixed wings — also a biplane but with two independent wings.
Tim Draper, the primary funder of Alef, in front of one of the working prototypes
The Alef’s trick is that the passenger compartment rotates, so that the driver faces forward in car mode, but it tilted as the vehicle tilts to continue to face forward when becoming a pilot.
The Alef can also do short hops without a transition to fixed-wing flight, but with much shorter range. This might also be used before regulatory approval is given to a vehicle which does the multirotor to fixed-wing transition. Today, the only vehicles which do that are those like the Osprey and some naval VTOL jets, and these require extraordinary piloting skills in the current regime. A short-hop flying car might mostly drive on the roads but hop over traffic jams, rivers or other short distances.
The Alef is likely to be a fairly sucky car, but it will be good enough to get you to and from the places you take off and land. Being able to drive to those places also solves the major noise problem of e-VTOLs — I have said that I would love to have an e-VTOL and take off from my driveway, but I refuse to let my neighbor do so. The Alef fixes that paradox.
Is this a good idea?
Most teams have not made true drive/fly flying cars because for e-VTOL, weight is everything. In fact, right now the physics are barely there. As such, most teams don’t want to put anything in their vehicle that they don’t need to. The wheels and other components used in driving all all dead weight while flying. If you use a liquid fuel power train, you can get the spare power to carry that weight, but in an e-VTOL that capacity is precious.
Inside one of Alef’s flying prototypes with basic mesh on top of rotors.
As such, most e-VTOL companies plan to land at special landing spots and vertiports, and passengers will just take a taxi (ideally a robotaxi) for the land part of their journey. Do the ground part in a pure car, and the air part in a pure plane.
So why, other than convenience, does the Alef make sense? The Alef is designed to fit in a regular parking space or garage. Owners can keep it in their home, but it can take off or land anywhere they can get approved to do this, typically any parking lot with a wide enough piece of pavement. The roofs of existing parking garages will be ideal.
Other e-VTOLS with large wings are big, and it’s an open question of where to put them when there are large numbers of them. Most plans involve new and expensive “vertiport” infrastructure on the roofs of office buildings and other locations, with an associated long trip to the ground if you aren’t going to that building. Once vehicles land at the vertiports they need to be able to move off the pads into areas for storage or charging. If they don’t have wheels this actually can be challenging (as such they probably will have small wheels which allow limited towing.) These vehicles take up 4-5 times the space and that’s a problem if there are millions of them in town.
The Alef will be able to use the large supply of car parking, including personal garages. They will be able to charge in any charger meant for electric vehicles. A hybrid fuel version would be able to fill up at gas stations. (One reason fossil vertiports are a challenge is that it’s hard to get regulatory approval for a gas station on top of a buliding — they vehicles must go elsewhere to tank up.)
If batteries don’t get any better, the Alef’s dead-weight may be too much. But it’s not an unreasonable bet that in the future, battery or hydrogen technology might get to the point where the Alef can bear the cost of the weight of its driving components. The grille on the top also has weight and impedes airflow, though all vehicles need to make sure people on the ground are protected from their rotors.
Other vehicles
Some estimates suggest there are as many as 600 different teams trying to make new VTOL flying vehicles, mostly electric. There are many different types of vehicles which might compete with the Alef
- The Aska is another VTOL fly/drive vehicle that fits in an ordinary parking space. It uses a more complex unfolding mechanism as well as a titling wing (with thus tilting rotors) and uses liquid fuel to get range. It’s also pre-production and also claims to be the first — we’ll see what vehicle gets to actual sales first!
- The Blackfly tilts the whole vehicle and the solo pilot along with it. It can’t drive, but has done many live flying demonstrations, including with unskilled pilots.
- Many pure-multirotor options are already present which are fairly small, but not parking space small. They don’t transition which makes them much simpler, but this reduces their range.
- A few cars have unfolding wings and drive to an airport where they take off conventionally. Avoiding vertical take-off solves a lot of problems, but requiring an airport is a significant disadvantage otherwise.
- There are hundreds of designs with tilting wings or rotors which have large wingspans and don’t fold up. They won’t drive. One of the most prominent from Larry Page’s Kitty Hawk company, the Heaviside, was recently cancelled, which bodes ill for the industry.
- Airbus made a concept “Pop.Up” vehicle which consisted of a passenger pod. A flying multirotor roof could attach to the top to fly it around, then drop the pod into a set of wheels to drive around. It was never produced.
- A few vehicles follow the gyrocopter design. A gyrocopter is small, and if it has folding blades it can fit in the car form factor. A gyrocopter needs a very small runway unless there is strong wind, but does not need a full airport. The Pal-V is already in production.
