In Defense of the Drivable Airplane—Terrafugia CEO Responds to Legions of Doubters

We know our readers love to hear about radical new technologies and the business opportunities they create. So we weren’t shocked when our article last week about the Transition, the drivable airplane from Woburn, MA-based Terrafugia, turned up on Slashdot and brought more visitors to the site than any Xconomy story since our launch last summer (and temporarily brought down our Web server in the process).

But we were a bit surprised by the comments that readers left here and at Slashdot—the majority of which were critical, even dismissive, of Terrafugia’s concept as a viable business proposition. Given that “flying cars” have been fodder for sci-fi movies, cartoons, and Popular Mechanics covers since the 1930s, it’s understandable that some people feel jaded about the latest promises for airplane-automobile hybrids. But whether or not you’re personally interested in traveling in an airplane with folding wings that doubles as a road-worthy automobile, quite a few private pilots are—as the three-year waiting list for a Transition demonstrates.

Judging from the comments last week, many commenters hadn’t fully absorbed the factual points in the article (to put it politely). Others seemed to feel that because the concept of a car-plane hybrid has been on the drawing boards for so long, it must be inherently flawed. But if you hear out the prize-winning aerospace engineers at Terrafugia, you’ll begin to understand why they feel so certain that current-day materials and electronics make a roadable aircraft—one that’s safe both to fly and to drive—a feasible idea.

In the spirit of friendly debate, we boiled down the hundreds of comments to a dozen basic criticisms, then asked Carl Dietrich, Terrafugia’s CEO and co-founder, to respond to each one. The text of our conversation follows. Please keep in mind that the questions below represent our summaries of the most commonly registered criticisms. They don’t necessarily reflect the opinions of Xconomy or its editors.

Xconomy: Thanks for speaking with us again so soon. The first and most repeated criticism of Terrafugia’s work that we heard from readers last week went like this: “Just look how many bad drivers there are on the roads. Being a pilot takes much more skill than driving. So just imagine the havoc if lots of drivers had flying cars.”

Carl Dietrich, CEO and co-founder of TerrafugiaCarl Dietrich: This is one of the most common misconceptions about the Transition. People assume that since we’re building a roadable aircraft it must be a flying car, and therefore will be sold to everybody who drives a car, and that’s just not the case. The vehicle will be sold to licensed private pilots and sport pilots, and these people will have gone through significant training in order to operate a vehicle like this. And they will hold a completely different type of license [from a driver’s license]. It’s not something where there is going to be one of these things in every garage. It will be a rarity to see one of these vehicles for the foreseeable future. So you’re not going to turn around one day all of a sudden and see the skies blackened with thousands of Transitions. The real market for these vehicles is solidly in the hundreds of units per year. For cars, you’re talking hundreds of thousands of units. It’s a very different scale. This is an airplane first, and not a replacement for anybody’s car.

X: Criticism number two: Light aircraft have a higher fatality rate per passenger mile than cars.

CD: The absolute number of accidents and fatalities in light aircraft is substantially smaller, of course, than in automobiles. I wouldn’t be surprised if it were correct that accidents and fatalities per passenger mile are somewhat higher. But the things we’re doing to address those issues are what I think is important. There is a market for general aviation, so the question is what can we do to make it better, to make it safer. And I believe we’re doing a lot to make it safer.

Specifically, not only do we have this rocket-deployed parachute that can bring the entire vehicle down if you’re in a bad scenario, but we’re designing the vehicle with safety cages and crumple zones. So we are doing more for survivability than probably any other light aircraft out there, because we are absolutely building it for driving on the road. We believe we are pioneering a lot of new ground in terms of light-sport aircraft.

In addition to that, there’s the fact that the vehicle lands at a relatively slow speed compared with other aircraft. It stalls at 45 knots. That’s about 52 miles per hour. In an emergency landing, you can touch down at that speed. If you are touching down on an unimproved field, it’s not going to be comfortable, but the safety cage is designed to take the impact of the entire vehicle slamming into a brick wall at that speed and remain intact around the occupants.

X: With the soaring cost of aviation fuel, isn’t this a lousy time to be marketing a new gas-guzzling private plane?

CD: It would be, if we were selling a gas-guzzling vehicle, and if we were selling a vehicle that ran on aviation fuel. But we are selling a vehicle that uses super-unleaded automobile gas, and that will get about 27.5 miles per gallon flying at 115 miles per hour, which is better mileage than most cars get on the highway right now, and at nearly twice the speed. So from a fuel-economy perspective, it’s actually one of the greenest planes out there. And the Transition is such a light vehicle that the mileage should be quite good on the road. We are expecting between 30 and 40 miles per gallon.

X: With avgas so expensive these days, a lot of pilots are flying less, and are getting rusty—so it’s a dangerous time to be putting them in small planes.

CD: It’s a good point that gas prices are going up and causing pilots to fly their vehicles less. But because the Transition uses super-unleaded automobile gas, you should be able to fly more often than you would if you were using normal avgas, because it’s like driving your car, only with better gas mileage. The second thing I would suggest is that if you own a Transition, you are likely to fly more often and stay more current than you would in another aircraft, because it’s sitting in your driveway or your garage and you might just take it to Nantucket, and once you get there you can drive it around the island. Chances are you will use this vehicle more often than you would your normal plane, because you know if bad weather came you could still get home. Though if you were on Nantucket, you might have to take the ferry.

Terrafugia Transition—Wings UnfoldingX: Flying cars/drivable airplanes are both poor cars and poor airplanes.

CD: There is definitely a degree of truth to that. Anytime you are making a dual-use vehicle, you do implicitly make compromises. But every vehicle out there has compromises. The question is what is the mission of the vehicle, and is there a market for a vehicle with those compromises? Yes, it is possible to make a higher-performance airplane than the Transition. And of course it’s possible to make a higher-performance car than the Transition. But neither that airplane nor that car will accomplish the mission that the Transition can accomplish.

What you need to ask is, is it possible to build a higher-performance roadable aircraft? That’s what we would compare ourselves against. And there is clearly a market for roadable aircraft. Back in 1968, Moult Taylor got 278 deposits for his Aerocar. From an aircraft sales perspective, that is a very encouraging number that shows significant demand. We can make a lot of money on a niche product that has a very particular role.

X: The Transition will be so light and will have such a large side-facing surface area that crosswinds will blow it off the road. If you take it across the Mackinac Bridge, you’re going to end up in Lake Michigan.

CD: Technically, there is some validity to the point. When we started down this path we looked at this a lot, and it turns out that roughly two percent of days—or seven days a year—it is windy enough that it would probably be a bad idea to go driving in this vehicle. And we will have clearly laid-out guidelines in our pilots’ operating handbook for when you should not consider taking this vehicle out. But pilots are used to those sorts of constraints on their operation. Many pilots, myself included, are not instrument-rated, meaning it’s not legal for me to fly through clouds. A visual-flight-rules-only, or VFR, pilot can only fly on 40 to 60 percent of the days in a year. But if the Transition allows you to drive on 98 percent of days, then there is a huge new level of flexibility and freedom.

Is the Transition more sensitive to side gusts than your car? Absolutely, it is. Quite a bit more. Does that mean it’s dangerous? No, it means the operator has to be aware of the limitations of the vehicle. And pilots have it drilled into them that airplanes are very different from cars and have much stricter limitations on when and how you can operate them. That’s part of the licensing and certification process for owning and operating an aircraft. And we will be incorporating a significant amount of training with this vehicle.

X: If you can afford a Transition, you can afford both a real plane and a rental car.

CD: Right. Some people also comment that, “For this price I could buy an old Cessna and a nice car, so what’s the advantage?” The advantage of the Transition over an airplane and a car is that you only have your car at one airport. If you fly your plane to a different airport, you don’t have your car.

Terrafugia’s Transition Takes OffSure, you could buy a fleet of Yugos and put them at airports all over New England. But there is a balance somewhere. There are some pilots who do have a couple of cars, if they commonly commute between two specific airports. Obviously, this might not be the vehicle for them. But most of the time, if you are flying, you want to go someplace new. And two-thirds of the airports out there don’t have rental car facilities. And if you do encounter weather on your way to where you’re going, the Transition is the only vehicle that allows you do divert to the nearest airport, fold up your wings, and keep going. For a lot of general aviation pilots, a vehicle that is able to fold its wings and drive on the road actually does make sense. We can look at our own order book and see that there are people who want this badly enough to put down money for it.

X: Even a small amount of road damage from fender-benders, potholes, rocks, and the like could make flying dangerous—or at least make it necessary to do a tedious inspection before flying again.

CD: Should you find yourself in a situation where you’re parked somewhere and somebody backs up their car into your vehicle, it’s not going to render the vehicle un-airworthy. That’s where we are spending a lot of our intellectual resources—on making the vehicle really robust to the abuses you may encounter when you’re driving. And that’s a lot of what we’re seeking patent protection for—things like the deformable, aerodynamic bumper on the canard, and the elevator in the back [that] is also a deformable bumper. If somebody is parallel parking and they nudge you, they are not going to destroy your vehicle.

These things are incredibly important when you’re talking about insurance costs. That’s another part of making this practical—keeping the insurance costs down. It is an expensive vehicle, so it’s going to cost a lot more than a car to insure. But we’ve been talking with Avemco, which does aviation insurance, about the features that we’re putting into this vehicle to protect it in a road environment. I don’t want to quote numbers, but we expect to be able to insure this for the same as you would pay to insure another aircraft, despite the fact that there is more exposure.

Also, you always need to pre-flight inspect an aircraft. If you are trusting your life to this vehicle, you are always going to want to inspect it before you go flying in it. That is part of normal aircraft operations. That means walking around the vehicle and visually and tactilely checking out all of the surfaces. We have made it particularly easy to know when things are in place or not in place, and if they’re not in place, then you know you need to take it to an airframe or power-plant mechanic to get a repair.

X: Anything that has to pass highway safety tests will be way too heavy to fly, and anything that is light enough to fly will be incapable of surviving a roadway crash.

CD: Well, I would ask people who say that to visit us at our next trade show and give us the opportunity to show them how we are doing what they say is impossible. Specifically, we are using very advanced carbon-fiber construction techniques that give us inherent strength-to-weight advantages over normal automotive construction techniques. That is the basis on which we can build a vehicle that is designed to take automotive crash tests and yet still be light enough to fly.

X: High insurance, liability, and litigation costs kill off every company that attempts to build a flying car.

CD: I don’t think anybody has actually gotten to the stage where it had the opportunity to put them out of business. Moult Taylor, the most successful roadable aircraft builder in history, only built five prototypes and never went into production, so he never had the opportunity to get into that position. We are anticipating that we will get farther along. And we will be in that position where somebody will, one day, crash in one of our vehicles. And we want to provide them with as much protection as possible so that their insurance rates will be low, and that’s why we are investing in these technologies for crash protection. In terms of litigation, that is why we will be insured as a company. There are always risks when you are operating a vehicle. But we are trying to do everything we can from an engineering standpoint to satisfy both the need for this vehicle in the marketplace and the need for it to be insurable.

X: We already have enough trouble with greenhouse gas emissions. Why put all this brainpower into one more CO2-emitting vehicle? Wouldn’t it be smarter to come up with a better bicycle, or a way to get people to stop driving?

CD: This is a philosophical question, so I will respond with a philosophical answer. But I will qualify it by saying this is my personal view. I believe that it is in our global interest to do things that improve the quality of human life and the freedoms of humanity. I don’t think forcing people to ride bicycles does that. I love riding my bicycle into work. I am not trying to de-emphasize the importance of being a conscientious user of natural resources. But what we’re talking about here is fundamental human progress. I don’t believe that it is in our interest as a society to restrict technological development when there is a clear market for it, it happens to improve freedom, and it has a lower impact on the environment than other means of transportation like driving your car.

Terrafugia’s Transition in a Lightning StormWhen you combine those things, I think you have an enabling technology. If people can travel to more places, faster, using less gas, who knows what it will spawn? It is a net-win scenario. Does that mean everybody should travel in a Transition? Of course not. But there are times and places for it. And the bottom line is that there is a real demand for it, and that is what we are seeking to satisfy.

X: Others have tried to build flying cars or roadable aircraft, and they have always failed. What makes this attempt any different?

CD: The short answer is, timing and technology. From a timing perspective, we have the emergence of the new light-sport aircraft rules, which not only create a new type of license but an entirely new way of bringing a sport aircraft to market in a very short amount of time. So from a business perspective, this is an incredible opportunity to get a high rate of return. The other reason is the technology. With advanced carbon-fiber composite materials and modern glass-cockpit avionics, we can provide a lot more functionality in a smaller package that is also safer and have it be insurable. That convergence of timing and technology is why I think this can finally work now.

Wade Roush is a contributing editor at Xconomy. Follow @wroush

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