Carplane is an innovative enterprise in Braunschweig, Germany, intent on producing a hybrid vehicle that, while it resembles the Rutan Model 367 BiPod, differs in significant ways.
The company’s “pitch” is similar to those from other roadable car developers since the Waterman Aerobile or Taylor AeroCar. “Imagine the daily commute without transfers, exits, congestion, or missed connections,” the German Center for Research and Innovation envisions. “As an aircraft that can also drive on roads, the Carplane® will head for its destination in a beeline without detours or stop-and-go traffic. Located in Lower Saxony, Germany, and under the general management of Angela Fleck, herself a pilot, the Carplane GmbH is in the process of building such a dual-mode vehicle. Designed as a Light Sport Aircraft (LSA), requiring only 20 hours of instruction to fly, commercial applications will include recreation, business travel, and emergency service.”
Waterman Aerobile (1935) on display in Udvar-Hazy Museum. Photo: Smithsonian Institution
Like the BiPod, Carplane has a twin cockpit catamaran-like fuselage arrangement, a “hybrid” power system, and the ability to be transformed from road to aerial mode. Like the BiPod, hard details as to construction or propulsion are spotty (although its appearance at AirVenture 2011 may add to BiPod’s knowledge base).
Unlike the BiPod, which apparently requires operators to attach or detach wings as part of its transformation, Carplane has a highly automated and very slick mechanism that takes only 15 seconds to swap modes. Since the makers use electric drive for highway driving and internal-combustion power for sky commutes, that switchover is made easier by the fact that the “air-mode” engine is in a cowling above the center of the wing, not hidden inside the fuselage as on the BiPod.
“The air-mode combustion motor,” according to Carplane, “uses premium fuel and operates at low RPM with relatively low consumption, noise and emissions.”
Optimizing “lift in air-mode and generat[ing] downforce in road-mode,” Carplane enables “autobahn speeds (109 miles per hour or 176 kilometers per hour).” As an airplane, it’s limited to LSA performance, cruising at 136 miles per hour (118 knots), considerably slower than BiPod’s claim of 200 mph.
While BiPod is a budget project created by a small crew with private funds, Carplane is being developed with government support and sponsorship from Niedersachen Aviation, an aerospace consortium in northern Germany. It’s been presented, in model form, at this year’s Hannover Fair and Friedrichshafen’s Aero Expo, with obvious interest from government leaders.
Because system details are not available, questions remain about the batteries and power systems used in Carplane. The 136 mph air speed is plausible, but the power and duration necessary to cruise the autobahn on electric power while staying within LSA weight limits would seem a real breakthrough. We eagerly await more information.
Thank you to John Brown of Carplane for alerting your editor to this exciting development.
Comments 8
Dean,
thanks for the above article about our Carplane. Apart from the obvious (i.e. “Carplane” isn’t a German word), your readers might be interested to know that our Govt. sponsors employed technology scouts to woo us to relocate to Germany’ Research Airport from our previous location where we’ve been building our patented Carplane since 2008. (There are two other firms building roadable aircraft in that region right now.)
Furthermore, we don’t claim a breakthrough in electric technology. We use a piston engine for air-mode. Our battery will only get us 50kms on flat ground(to the next airstrip) in road-mode. After that, we use the piston engine as a range-extender to recharge the battery if we plan to continue via road-mode.
Dean …one more thing… your quote is not our “pitch”. You apparently found it on the site of “germaninnovation.org”… a commentator like you. Waterman & Taylor used “modular” concepts (separate wings) just like the “BiPod”. However, as you rightly pointed out, our concept is “integrated”, i.e. our wings extend via “push-button” in 15 seconds. We believe this is an important feature for marketability. Cheers, John
(Editor’s Note: Thank you for the clarifications, and apologies for mixing and matching attributions for quotations.)
Still…I remain dubious about the flying car concept for more then leisure/niche use. They neither really fly well, nor ride really well compared to their “straight” buddies. The approach of STOL hubs (near city; affordable real estate) & automated cars looks more promising on a large scale. I would even dare to say that automated cars are the “mobility” brick that really will resucitate general aviation. That seamless transfer from car to plane to (automated, ordered just in time + without chauffeur cost) car could fully unlock the time saving potential of small aeroplanes. But I love the Isetta looks of the Waterman Aerobile :-)…
I’m curious why you even _need_ “maximum downforce” if the vehicle tops out at 109mph? I am also curious how much weight all of those automated wing-deployment mechanisms add to the design. Every pound of unnecessary weight in an airplane reduces useable fuel load or useable payload. Extra weight can reduce climb rate and range. These are facts that CAFE foundation members should know inherently… I’m surprised it wasn’t a question or an issue that this article explored.
Noel, sorry for the delay in responding to your questions. I was on holiday last week and we’re getting a design award from the Transport Minister tomorrow which has kept us busy. Before that, I’d been following the other thread and missed your questions here.
1). A roadable LSA weighing 650kgs has a weight comparable to a Formula 1 racecar. Back when I was learning to fly, I sometimes hung out at the hangar of Jack (now Sir Jack Brabham). He introduced aerodynamics to Formula 1 racing in a big way and as a result won many races in the 1970s. Listening to him influenced me. The other influence was Luigi Pellarini who built two roadable aircraft for an Alfa Romeo supplier in the late 1940s in Italy. He emigrated to Australia and hung out at the same airport in the 1970s. Jack and Luigi both made clear to me the benefits of downforce (and skirts, spoilers, etc.) when keeping a leightweight vehicle on the ground. That’s important because airplanes are designed to leave the ground as soon as possible. In our opinion, a good roadable aircraft needs to pay attention to “reversing” lift for road mode. Otherwise its road speed will be like a plane taxiing.
2). Since we started, we’ve reduced the weight of the wing storage mechanism by more than 46kgs. I think you’d be surprised how light it is. But since it’s the core of our IP, we aren’t discussing it publicly. Think of it like this: All we’re doing is automating what glider pilots do every weekend once they’ve towed their plane to the airstrip. Each wing is centrally balanced on the tip of two counter-rotating beams. What adds weight is more the empennage extension (due to flatter, moment arm, etc.). Here in Lower Saxony, however, we have the benefit of VW, Airbus and wind-energy companies being close-by with an entire carbon-fibre industry sprouting up around them. That helps.
Noel,
The fact is that anything will fly if you put enough energy behind it. The designers configuration decisions start with the opporational objective of the vehicle, then the rationalisations, innovations, prototypes, rethinks and reprototypes begin. It is early days for CarPlane yet.
The chairman of the panel of 3 professors (aerodynamics/structures/ guidance faculties) assigned by the Govt. to evaluate Carplane® said much the same thing when he opened procedings; “even a refrigerator will fly if you add enough power”, he joked. But after taking a look, the panel unanimously approved the project. Design experiments on initial concepts started in 1978. The current design evoled Nov. 2006. It was re-worked several times, then tested as a model before construction began on Sept. 1, 2008. During construction, the overall height and the weight of the extension mechanism were reduced. And there will certainly be many more modifications before we get airborne. But it’s mostly weight-tweaking now rather than any fundamental aerodynamic or configurational changes. So, even though it’s been 33 years, I agree; it’s still “early days” for Carplane®. These things take time.
hello John. ..
is it possible to get an update on where your project is at..
kind regards
Joe.