Wanting flying cars won’t make them real
People say they’d buy a vehicle with vertical lift and long range — in other words, the impossible
This is not an engineering story. Oh, there will be plenty of discussion regarding horsepower, lift and even some calculations — probably erroneous as I did the calculating — of the thrust required to get a helicopter off the ground compared with the power needed to drive a car. Nonetheless, this is definitely not an engineering story.
Instead, this is about focus groups. Or, more accurately, why 80 per cent of products, despite being thoroughly vetted through focus groups, fail within the first six months. Why, as Harvard Business School professor Gerald Zaltman wrote in How Customers Think, “the correlation between stated intent and actual behaviour is usually low and negative.”
Or, as UX magazine’s Jay Eskenazi explains: “If you just show people a product, they will give you an opinion or reaction. If you have them actually use or interact with the product, their feedback will be based on their experience, which is far superior to their initial, hypothetical thoughts.” In other words, the more abstracted an expressed opinion is from reality, the more likely it is that the research participant’s opinion will be incorrect, inaccurate or misleading.
This explains why, according to the University of Michigan’s A Survey of Public Opinion About Flying Cars, not only do consumers really want their next cars to be completely electric, they also want them to fly.
For those already thinking that there must have been some magic mushrooms involved, consider this further demand: they also want their future flying car to have a range of at least 640 kilometres (400 miles).
Let’s examine those expectations, shall we?
Assume, for the moment, that the respondents were talking about 640 km of driving range. Extrapolating from current electric car performance, it takes about 30 to 35 kilowatt-hours of lithium-ion to reliably promise 160 km of range. Six hundred and forty kilometres, then, would require somewhere between 120 and 140 kWh usable battery capacity. The problem is, using current technology, that represents somewhere between 480 kilograms (1,056 pounds) and 560 kg (1,232 lbs) of battery weight.
Now consider that a four-passenger aircraft such as Cessna’s 172 — the world’s most popular four-passenger recreational aircraft — weighs about 770 kg (around 1,700 lbs). In other words, the battery that would drive a car 640 km would weigh almost as much as a four-passenger aircraft. Now consider that a Tesla Model S, with 100 kWh of battery and 500 km (315 miles) of range, weighs roughly 2,300 kg. In other words, an electrically powered car able to carry four passengers — which the Sustainable Worldwide Transportation study’s respondents say is another “must have” — with enough battery to drive 640 km (never mind the 960 klicks some respondents wanted) has virtually no hope of flying.
But, wait — as Ron Popeil (he of Veg-O-Matic fame) used to say — there’s more! Fully 83.1 per cent of these same respondents say their future flying car should also offer vertical takeoff and landing, the whole point being enhanced convenience and shorter travel times.
The problem here is that helicopters, which our flying cars would now have to be, require a lot more power than fixed-wing aircraft (essentially a helicopter has to lift its weight with sheer power, while an airplane gets its lift from horizontal speed). A rough calculation reveals that one horsepower is needed to lift something between two and 3.5 kg of car/ plane/helicopter off the ground.
In other words, just getting a Tesla 100 D’s battery off the ground would require anywhere between 150 and 200 hp. Getting the whole car to take off vertically would require anywhere from 750 to 1,000 hp. Indeed, a Bell 429 helicopter, weighing in a comparatively svelte 2,025 kg, boasts twin Pratt & Whitney turbo-shafts with no less than 1,250 hp.
Now before you all send me YouTube videos of Lilium’s sensational Vertical Take-off and Landing Jet, know that there is more than a little skepticism than it can deliver its promised 300-km range using only its Tesla-like electric batteries.
Besides, it is not in any way a car, despite the blogosphere’s attempt to describe it as such. Indeed, the one flying car that does use some electric power, the AeroMobil 3.0, is actually a hybrid, its Chevrolet Volt-like 2.0-litre gasoline-fuelled powertrain consuming about 4.0 L/100 km while driving and about 12 L/100 km jetting around at 260 km/h. It is also, despite having 300 turbocharged horsepower at its disposal, not capable of vertical takeoff.
Oh and by the way, according to Wired magazine, AeroMobil is projecting its flying car will cost “between the price of a supercar and a small plane.” In other words, it is no more indicative that our future is practical, four-door, vertical-takeoff-and-landing flying electric cars than HBO’s You Me Her is proof that unicorns really exist.
Nonetheless, as seemingly outrageous as the survey’s conclusions may be, the source — the University of Michigan — is an entirely credible institution (its studies on fleetwide fuel economy for newly registered cars is considered the bible of corporate average fuel economy).
Nor is this an April Fool’s joke. Authors Michael Sivak and Brandon Schoettle conclude that, “despite the fact most Americans are very concerned about the safety of flying cars, most would still ultimately like to use them.”
You don’t need to be a mathematician to understand that the chances 20 times more Americans are suddenly going to open their wallets to buy electric cars is not realistic. Just as you don’t have to be an aeronautical engineer to understand that a four-passenger electric car with a range of 640 km isn’t going to fly, no matter how many people say they want one.