Great stuff, Zane, as always. I love the over-the-shoulder perspective. Your music and editing are also just as good as ever.

Wouldn't we all love to get our hands on that thing and go wring it out for an hour or two!!!

finally got a chance to watch the video and read the article, great job Z!

Looked like a lot of fun!

Super job on video, and the glass cockpit is fantastic.

Coondawg wrote:glass cockpit is fantastic.

Heh heh... that's the first joke I've heard about that.

"Now this is what I meant by a glass panel!"

some kind of contraption for sure...!

Denali wrote:
On a push pull, are the props generally the same (or can they be different?) because of the turbulence, air velocity differential, and other factors? I figure you really can't have too big of a torque difference front vs rear because that would create some roll wouldn't it?

Like everything in aviation, it depends, but generally speaking, you would want different props. Ideally, you'd want the rear prop operating inside the propwash of the front engine. Propwash decreases in diameter (not taking into account fuselage/wing effects, hence the "depends" qualifier) after it goes through the prop because the air is still accelerating and good old Bernoulli/Newton says its so. So in theory the rear engine should have a smaller diameter prop with a larger angle of incidence. If the rear prop is larger than the prop wash, the blades will have a drastic change in the angle of attack seen as you move radially out the blade. In the real world the props are usually the same size since the fuselage increases the diameter of the accelerated air from the front engine. The larger angle of incidence is to maintain an adequate angle of attack to produce meaning thrust in the higher velocity air. The other big detractor from the efficency of the rear prop is any fuselage and wing structure that affects the inflow into the prop. Anything that disturbs the airflow, especially wings, will cause each prop blade to see cyclical changes in the AoA as the blade rotates. Because of these factors, the rear prop on the Skymaster is only ~70% efficient, compared to the front which is around 80-85% efficient (based on internet searching, so don't quote me for a research paper). Note that this is different than contra-rotating props that are close together (thus not having the fuselage interference issues) where the rear prop is more efficient than the front.

Regarding torque effects, I can't imagine there is too much of a concern of having the engines at different power settings. The engines are counter rotating (as installed), so with both engines running the torque effects tend to cancel. The biggest difference you could have would be one engine shut down, at which point you are no worse off than any other 130 hp conventional plane (torque wise). Powerful single engine prop planes (WWII fighters) could torque roll at low airspeeds and therefore have to incrementally increase power on takeoff as airspeed increases, but the more humbly powered GA planes don't usually have that restriction.


Oh, and awesome video and write up. Thanks Zane

I know that Alec and Doug are very scientific about the design of the aircraft, so it would be cool to hear an explanation of their findings with the rear engine performance. I read on their site that they're further testing the wing as a model in a wind tunnel with some Brazilian university.

how noisy would u suppose it is inside the cockpit...??!!

jomac wrote:how noisy would u suppose it is inside the cockpit...??!!

I was curious about this, too. I was reading a book a while back by a pilot of the cessna skymaster, and he said that it was extremely loud inside (like deafening). As a kid, the skymaster was one of my all time favorite planes (right up there with the p-38), but it's far from that these days.

I've flown in a few Skymasters and didn't find them significantly noisier than other planes.

This is what I love about the experimental/amateur built category. You can crank out all the kit planes you like, that's cool. But, these guys really know how to put the "experimental" in homebuilding. Even if it weren't a very practical airplane, I'd still give them bundles of credit for thinking outside the box, and creating a fascinating approach to little airplanes and off airport.....

MTV

Whatever happened to this thing? It's been 5 years nary a peep.

More trouble then it was worth comes to mind. Darwinism applies to aviation too it seems. Neat experiment though, major outside the box thinking.

Saw this thing in Alaska in summer 2018 but it was wrecked shortly after, ditched into a lake. Not sure if it's back up and running? Looked sick, was the sequel to the double ender.

Good pic:


MY shit pics:

Is that just a single-ender?

CamTom12 wrote:Is that just a single-ender?

Yes and side-by-side seating

asa wrote:

CamTom12 wrote:Is that just a single-ender?

Yes and side-by-side seating

Cool!