Thursday, March 17, 2011

Roadable plane, flying car, whatever

I'm sorry but I just don't get the Transition roadable aircraft from Terrafugia. Sure, it's an interesting aeronautical engineering concept and so far it seems to do what it was designed to do, but I'm afraid I don't see the mission it's trying to satisfy. That could be a problem because I ought to be in the target demographic - pilot, some disposable income (no kids), frequent traveler for work and pleasure, etc. - assuming they want to start selling them at some point.

I was out for a bike ride earlier and I started thinking about the likely mission parameters of a roadable plane. (I do all my best thinking once I'm hypoxic.) Now, it's not particularly surprising to find that when designers set out to merge two highly disparate objectives they often end up compromising so far that neither mission is satisfied. The V-22 Osprey, the Porsche Panamera ("I wanted a 911 Carrera 4S but the wife insisted on a family car"), there are plenty of examples where compromise seems to have produced what we might politely term "thought-provoking" vehicles. Might the Transition be headed this way?

So I did a thought experiment. Let's suppose it's a Thursday afternoon and I'm heading from the Bay Area to Los Angeles for a few days. I have some stuff to do in LA on Friday morning so although I'm not exactly pushed for time I don't want to be traveling all night, either. Some sleep might be nice. Okay, so I leave work just after lunch and because I've planned ahead I've already got a bag packed. I would ordinarily head east on Hwy 24 from Berkeley, pick up I-680 south to I-580 east and then drive south on I-5. But now I'm in my Terrafugia Transition so I have options.

Quickly nixed is launching right off Hwy 24 as soon as I get through the Caldecott Tunnel. It's not the Highway Patrol or even the FAA regs that keep me on the ground; no, it's the good ol' Bay Area traffic! I'm barely doing 50 mph and I've already been carved up six times since exiting the tunnel. (Dude! This is a plane as well as a car!! Don't ding my wing!!) I'm a nervous wreck.

In any case, it's clear that I will have to follow protocol and head to an actual airport to get airborne. I usually fly (planes) out of Livermore, but since I'm coming from work I decide to head to Concord-Buchanan because it's closer. I get to KCCR after just half an hour (not bad!) and fill up with gas before entering the GA area. (Don't want to launch without lots of fuel!) I park outside an FBO and head in to get a weather briefing. Lucky me! It's CAVU all the way from Concord to Santa Monica and it takes only fifteen minutes to make my plan. I'll go VFR and get flight following in the air.

Now, I don't know about you but I find it physically impossible to spend any less than twenty minutes doing a pre-flight inspection. And this on a vehicle that is designed to move at about ten knots on the surface and then spend the vast majority of its operating time in the air. But this roadable plane thing is on another level. I'm going to spend at least that long, first checking that my shocks and struts are still operational (have you seen the state of Californian roads?), making sure that some delinquent didn't vandalize my ailerons while I was parked at work, checking that I didn't ding a leading edge with debris as I drove down Hwy 24 dodging pieces of truck tyre and an occasional piece of furniture... Oh, and I have to fold the wings out, too. You get my point. By the time I've finished my pre-flight I've been at KCCR for an hour; this for a CAVU day with no weather or mechanical issues to address. I can't see me doing it any faster.

I'm finally off! I climb to an initial altitude of 5,500 which is plenty for terrain clearance in Norcal. I'll have to climb later to get over the Tejon Pass, but one step at a time. The air is still - remarkable for Cali where we usually experience westerlies of 20+ knots - so I make good ground speed down to Socal. I'm having a good day. Traffic in and around KSMO is light, no biz jets to move me out over West Hollywood while I await my turn to land. I'm on short final for KSMO just 2.5 hours after wheels up at Concord. Bada bing!

I taxi to an FBO and reconvert my plane to a car - another ten minutes - and dash inside to pee. (There has yet to be a pilot born who didn't need to pee microseconds after exiting the cockpit.) Now I'm driving out the gate at SMO and heading up to Westwood where I'm staying. It takes me another 20 minutes to get there, which isn't bad for LA traffic. I have arrived!

Okay, so let's sum up. We had 30 minutes getting to the departure airport, an hour on the ground preparing to fly, 2.5 hours in the air and another 30 minutes getting from the arrival airport to my actual destination. Total journey time: 4 hours, 30 minutes. Not bad. Especially for an afternoon departure.

But look at all the good luck that had to happen to get my total journey "down" to 4.5 hours. Had weather been slightly iffy, had I found an issue with a flight control, or collided with a piece of stray rubber on the way to my departure airport then I would have added another hour at least to the total.

What's the alternative? Well, back before 9/11 my rule was that if my destination was 5 hrs or less away, I drove. More than 5 hrs and I'd consider a commercial flight. Since 9/11, however, I've upped my cutoff to 6 hrs. There is also the issue of baggage. Time was you could take useful things with you - shampoo, nail clippers,... - in your carry-on. Ha! I could check a bag, of course, and pay $20 each way to have it possibly travel with me. No, all in all, even if my destination is a 6-hour drive away I will still consider driving unless there's a good reason not to.

Okay, so the driving alternative is to head home from work late afternoon, maybe go for a run and/or take a short nap, wait for traffic to dissipate and get on the road for about 7 pm, putting me at my LA destination right about half-past midnight. Not only have I arrived with plenty of time to sleep, I've got so much crap with me that I look like I could be moving house. (Packing light is for air travel.) I decided to throw my bike in the car in case my friends, John and Tom can make a ride on Saturday morning. I also brought a couple of bottles of red wine from a recent trip to Sonoma. And not only do I have all my toiletries, I purposely brought the biggest damn bottle of shampoo I could find, just to make a point. (Yes, Mr TSA Agent, that is much bigger than 100 ml!)

For me this flying car thing just makes no sense, not even under ideal conditions. I didn't even have to get into the crosswind landing characteristics, or the price, or the insurance, to come to the conclusion that I'm not a buyer. Call me a coward but I would really prefer to keep my flying machines well away from roads and other cars. I can state quite categorically that I hope never to be on a highway in a winged vehicle - unless the alternative is a dead stick landing into the cow pasture at Coalinga, in which case I'd like a nice straight section of I-5, please.


  1. Unfortunately, your comment on to the article "Why Flying Cars Endure" came in just after mine (Oscar Fleury) -- did you read it? If not, you should indeed!

  2. Hi Oscar, you make some interesting observations. (Here's a link to the avweb blog for those who didn't see it already: )

    In my post I considered the Terrafugia only. I happen to think that there are other ideas for drivable planes/copters that could well make a lot of sense for certain applications. I'm thinking of the Maverick "powered chute-car," for example. For bush work in places like Africa or even rural America, a vehicle such as the Maverick could be a really good option. Where I have yet to see a practical suggestion is in the arena of urban US transportation. The Terrafugia looks like that's what it's aiming for - it doesn't look like a bush vehicle to me - but that's where the roadable plane/flying car ideas come unstuck. Outside of the urban US many options seem quite viable by comparison.

  3. Hi Flying Donald (from Oscar Fleury)

    Sorry: your blogspot featuring no reporting of replies, I missed out on yours until to date.

    Thanks for noting some interesting observations in my last two comments on AVweb (to which, alas, none of the AVweb readers deemed to reply).

    I'm the inventor of another rotary wing concept eligible as a successor of the motorcar for individual intercity mobility -- besides the only known to date, i.e. the US tilt-rotor with its military and civil versions defining state-of-the-art VERTOL / fast-cruising (yet not autorotatable) technology.

    Invented in 1982, my concept remains unknown to date because I'm lacking financial means to ensure worldwide protection deemed to be a must for game-changing inventions.

    It so happens that in the meantime the US tilt-rotor project was launched in the early eighties -- only for me to realize shortly after it was not autorotatable and thus ineligible for civil certification. Moreover, I realized that the US military (besides fiercely seeking to preserve their concept from a civil career) were keen on making believe the entire world that transition from hovering to cruising was an extremely challenging issue... whereby at least this one hoax has been busted recently when it became known that the aircraft flies perfectly well in the "loitering" configuration with its rotors tilted at 45°!

    Now I find myself quite in a dilemma: not knowing whether I should go full steam for the development of a variable/reversible twist rotor blade in order to enable an ultra-light tilt-rotor project cured from the autorotation problem -- or whether I should put all my stakes (mainly free working time as an old-age pensioner, along with a mechanical workshop) into my own revolutionary rotary-wing concept.

    I had a third option until recently: to become world-famous (and thus maybe eligible for some sponsorship) by building a propeller-driven wind-powered cart designed to go faster than the wind blowing exactly from stern... Alas, a few days ago I came across a website listing reports and videos of DDFTTW (Direct-Downwind Faster Than The Wind) wheeled vehicles -- with current world record set at 2,7 times wind-speed!

    Oscar Fleury

  4. Hi Oscar,

    "...whether I should go full steam for the development of a variable/reversible twist rotor blade in order to enable an ultra-light tilt-rotor project cured from the autorotation problem -- or whether I should put all my stakes (mainly free working time as an old-age pensioner, along with a mechanical workshop) into my own revolutionary rotary-wing concept."

    Build a model, test it and publish it! As a scientist myself, that's one sure way to know that your ideas will endure. Although I'm not a modeler of any description, it looks to me like there are truly remarkable parts available now, for everything from autonomous aerial vehicles that can carry small cameras to tiny jets (that have been put onto the Cri-Cri, for example).

    Funny you should mention faster than wind vehicles. I was sailing a regatta this weekend out of the Corinthian Yacht Club in Tiburon, across from San Francisco. Hydroptere, the concept hydrofoil/yacht, is moored just outside the harbor there. What a machine! The Americas Cup 45s were out testing as we sailed home this evening, ripping 25-30 knots with ease. But 50+ kts DDW is something else entirely. Wow. Would have loved to see that!


    1. Hi practiCal fMRI,

      Thirty years ago, I announced my intent to build a DDFTTW-cart to my then boss, who reported to one of his wealthy friends... who promptly offered to pay the building materials and components for the project.

      Yet I had to renounce, not being sure my system would overcome friction and other losses, as it wasn't purely aerodynamic, but drag-based (with epicyclic pallets).

      Alas, the idea was put forth by a student as early as 1949, and realized twenty years later -- as I've just learned from Wikipedia!

      I warmly recommend you to look up the above referenced page -- and if you start your reading from the end of the text, you'll certainly appreciate the plain explanations of the three last paragraphs I just typed in to replace the original.

      If you can't see the second before last paragraph starting "To put it in a sentence: ...", my amendments may have been overwritten -- in that case, please tell me if you want to read them.

      Greetings from Oscar