Michael wrote:
So let’s sum-up ALL of the Twenty – First Century Super-Duper High Tech Features of the C4 that are being touted here :- Strutless high wing : Used in production Cessna C-34 circa 1935
- Continental 360 (w low compression pistons) : The IO-360 was first certified by the FAA on 15 May 1962 (developed from O-360 certified on 20 July 1955)
- 2 blade alumuinum alloy prop: McCauley, 1946 (One of the first production series is mounted on my 1947 Cessna 140)
You forgot the price. At US$250k of course this will sell. My guess it will cost 450k though.
Actually Mr Yeager does say it will sell for just under 400 k$ fully loaded.
I still don’t get this. No matter how many times I watch the video I hear him say that he cruises at 50-55 l/h which is in excess of 13 GPH and with CHT of 400-450 °F leaned 50°F ROP? That must be more or less WOT, right? I see MP 25+" and 2600 RPM.
50F ROP is also the highest-CHT point, which is dumb. There is no point in running any petrol engine at that point.
One should operate either 150F ROP (max power) or peak EGT / LOP (best SFC).
The former will draw some 20% more fuel than the latter but if you want “best power” for some reason, like takeoff/climb, or to reach the operating ceiling, you have to pay for it 
One of the main issues with a strutless light aircraft wing is weight, and it doesn’t matter from that point of view what materials are used. A strutless wing made with a given material will be heavier than a strutted wing made with the same material, as well as introducing fatigue issues that rarely occur with struts. The extra weight will reduce payload and climb rate, while providing some benefit in level speed. Where the trade-off is optimized depends on the design speed of the plane – which I’m told is why the Cessna Caravan has struts, because they found to be an overall better solution for that application, and material of construction wasn’t the issue. High strength to weight materials will equally make a strutted design lighter.
High wing aircraft do lend themselves to strutted designs better than low wing aircraft because the structure can be nicely triangulated around the cabin, and also because the struts are in tension in upright flight, so buckling (which BTW has nothing to do with strength of materials) is not so much of a consideration.
There are some structures that are impossible to build without materials having very high strength to weight ratio. These are often inertially loaded structures, high speed rotors being a good example, in which the weight of the structure generates its own loads. That is not the case for aircraft wings.
The Cessna Airmaster photo is fantastic…. In regard to that particular design, the strutless Airmaster and its descendants through the C195 have a problem with the big cantilever wing spar in that it occupies the same place in the cabin where you might like to position your head. I think they are wonderful looking planes, but not very comfortable to fly unless you are short. The Lockheed Vega (introduced in 1928) earlier resolved that issue by putting the crew in front of the wing spar and and passengers well behind, under the wing and the center of gravity…
Carbon fiber in aircraft construction is the future, not the past. The aerodynamic shape and weight savings cannot be matched by the old materials from the past.
The strutless planes shown are canvas covered. The Cessna’s with struts are metal/rivet not canvas or wood. The use of struts is clumsy, draggy, old school and wreck the siteview.
Aviathor wrote:
I still don’t get this.
What do you expect when it looks like he is trying to destroy that engine? I wouldn’t lend him a bicycle, much less an aeroplane. PS: But I agree. I don’t get it either. That is hardly what I would call a cruise setting. And I wouldn’t even think about the word “economy.”
Peter wrote:
One should operate either 150F ROP (max power)
That point isn’t really constant. But 50 is just too little if he wants to run ROP and waste fuel.
Martin wrote:
What do you expect when it looks like he is trying to destroy that engine? I wouldn’t lend him a bicycle, much less an aeroplane.
So far I was giving him the benefit of the doubt. I was wondering whether there was something I had missed, especially since nobody else picked up on it. So your comment comforts me
@Aviathor Frankly, I don’t like to judge from an armchair (that’s why I just hinted at it the first time), but when I hear 50 °F ROP, hair on the back of my neck stand up. Granted, he might not know any better and might just be following the book, however, ignorance changes nothing. That’s not a nice way to treat an engine. And the resulting numbers aren’t really surprising.
He knows what he is doing. He is a professional. That’s what my grandmother used to say.
