VincentWolf September 29, 2016 05:04 PM The future of air transport is in the plane designed by Luke Workman--as seen on this website http://newatlas.com/axial-stack-battery-supersonic-electric-airliners/45537/ Bob September 30, 2016 12:18 AM If each cabin had a narrower profile with fore and aft seating rather than side by side, the speed and range likely would have been much better. The propeller would probably have done better as a pusher rather than a tractor configuration. The extra wheels on the landing gear added a lot of weight. The center section of the wing and the motor housing appear much thicker than would be expected for such a small electric motor. Obviously, this was meant simply as a proof of concept design and the batteries are massive. Avianthro September 30, 2016 06:06 AM Sorry Mr. Wolf, but as someone with a pretty good basic aircraft engineering background, one of my majors as an undergrad, I can say that it would be possible even for a relative duffer like me to write a whole book on the fallacies and downright "ridiculosity" of the Luke Workman concept...first, and most deadly issue: power and energy storage density even for his fantasy battery concept is still about 1/10 that of jet A fuel. Second, electricity is fine for powering a propeller, but not for a jet propulsion system. Propellers are for subsonic aircraft. Jets are for supersonic. For this H2 fuel cell powered airplane, at least the issue of power and energy density has been eased a little bit, but there are still substantial weight penalties relative to an internal combustion engine that could burn renewable diesel fuel from Renewable Fischer Tropsch Synthesis (See e.g Audi-Sunfire and Doty Energy). Also, the challenge of an H2 storage and supply network relative to RFTS diesel is a very heavy factor to consider, along with costs for fuel cells and batteries. In evaluating any technology's sustainability, we must not look only at whether it uses a renewable fuel but whether it gives the best total lifetime cost efficiency. H2 fuel cell technology will not win on this all-important parameter. Really, folks, it's time to stop wasting good R&D time and money on silliness like this. watersworm September 30, 2016 06:58 AM One point versus Solar Impulse, with a "little" airspan of 21m the HY4 would take 4 "passengers" (1 pilot + 3 pax) whereas SI with something like 70m wings (or more ?) do carry one... pilot. Agree with Avianthro about hydrogen production. OK "if and when" renewable energy etc etc why not one day far far away... Agree also with the principle of "renewable" diesel or jet fuel, though, this time also its "when" etc etc Booleanboy September 30, 2016 07:14 AM Bob, this is a development platform for the hydrogen fuel cell system and I guess economy was an important factor. The airframe came from Pipistrel aircraft and looks like an engine nacelle has been grafted between two of their standard Taurus model fuselages. The Taurus is already available with an electric power system and I suspect doing things this way was much cheaper and quicker than developing an entire new aircraft from scratch. GaryP September 30, 2016 12:48 PM There is no zero emission vehicle unless the energy comes from dark matter. Someone has to produce the hydrogen and that takes energy and emissions. One has to look at the total process, not just the engine. Kpar September 30, 2016 02:30 PM "though there was no mention of where the fuel was sourced for today's test flight" My guess is coal. Mack McDowell September 30, 2016 03:41 PM Im glad most of the commentators are not the ones doing this research, it takes an open mind and a willingness to try something that seems outlandish and be willing to fail a few times before getting it right. everyone seems so certain that this idea and those of Workman just wont work without even taking time to test them out... Avianthro jet engines are possible with electric motors but the power densitiy issue hasnt been fixed so they havent really been made yet... a jet engine is just a hugely efficient and complicated ducted fan... Tom Lee Mullins October 1, 2016 09:48 AM I think the idea of a fuel cell powered plane is both cool and green but the design of this plane seems rather odd. It seems like a P38 but with the engine in the middle and the passengers where the P38 engines would be. I would rather have two fuel cell powered motors with the passengers in the middle like a P38. There are many green sources of hydrogen. One just has to look them up. George Kafantaris October 3, 2016 04:05 AM Hydrogen is the transportation fuel of the future. Hang on to your hats.