8 ms·

I'm surprised by the struts supporting the wing; that saves weight (probably important here), but at the cost of drag. Wikipedia suggests a rule of thumb of 20

by aidenn0 13d ago

I'm surprised by the struts supporting the wing; that saves weight (probably important here), but at the cost of drag. Wikipedia suggests a rule of thumb of 200mph being the break-even point for struts vs cantilever, and I would guess this plane is supposed to cruise faster than that. However, I didn't see the cruise speed listed anywhere; does someone know what they are targeting? On another note, other than the struts, the design is reminiscent of the DHC Dash-7, a STOL airliner from the '60s that also used slower propellers (with gearing instead of an electric motor, of course) to reduce noise. That plane wasn't particularly fast either (240kts max speed).

kirrent 13d ago
That sounds like the breakeven if you're holding wing geometry constant and want to compare cantilever weight cost to bracing drag cost. The real advantage is in allowing for thinner and higher aspect ratio wings like in the Boeing X-66 which was designed to fly considerably faster than 200mph and make fuel savings. I guess an additional advantage in this design is that the weight of the batteries is in the fuselage rather than the wing, so additional strengthening of some type may be necessary in either scenario.
- aidenn0 13d ago
  I'm terrible at estimating aspect ratios, but the plane in the video doesn't seem to be particularly high aspect ratio. Since they will be presumably holding less fuel, they could certainly be thinner though. While poking around their website to try and find good still images from a top-down angle of their demonstrator, I did notice that there is no bracing in the concept images of the ES-30, for whatever that is worth.
dingaling 13d ago
The Shorts 360, very similar to this aircraft in size, weight and structural design with a strut-braced wing, cruised at 216kt ( 249mph ) for 400nm with 36 pax, three crew and fuel for 50nm diversion and 45 min hold.

by aidenn0 13d ago

kirrent 13d ago

That sounds like the breakeven if you're holding wing geometry constant and want to compare cantilever weight cost to bracing drag cost. The real advantage is in allowing for thinner and higher aspect ratio wings like in the Boeing X-66 which was designed to fly considerably faster than 200mph and make fuel savings. I guess an additional advantage in this design is that the weight of the batteries is in the fuselage rather than the wing, so additional strengthening of some type may be necessary in either scenario.

aidenn0 13d ago
I'm terrible at estimating aspect ratios, but the plane in the video doesn't seem to be particularly high aspect ratio. Since they will be presumably holding less fuel, they could certainly be thinner though. While poking around their website to try and find good still images from a top-down angle of their demonstrator, I did notice that there is no bracing in the concept images of the ES-30, for whatever that is worth.

dingaling 13d ago

The Shorts 360, very similar to this aircraft in size, weight and structural design with a strut-braced wing, cruised at 216kt ( 249mph ) for 400nm with 36 pax, three crew and fuel for 50nm diversion and 45 min hold.