Eviation Alice Ready for First Flight.

[MIflyer]

Eviations's Alice prototype electric powered commuter aircraft is expected to make its first flight within the next week at its Arlington WA home field. News from Flying Magazine.

 

[SaparotRob]

That's just beautiful. Don't care if it works.

 

[Crimea_River]

Hopefully it will make a circuit before running out of power.

 

[Gnomey]

Nice!

 

[vikingBerserker]

Beautiful! I wonder if they'll cover the top portion of the plane with solar panels.

 

[MIflyer]

Beautiful! I wonder if they'll cover the top portion of the plane with solar panels.

I'll bet that windmills would work better. After all, the thing must be moving at 200-300MPH. May as well use all that moving air for something.

 

[nuuumannn]

Eviations's Alice prototype electric powered commuter aircraft is expected to make its first flight within the next week at its Arlington WA home field. News from Flying Magazine.

View attachment 654320

That's surely a digital rendering and not the final configuration of the aircraft?

The tail surfaces appear way too small and that Ki-46 style windscreen would be nothing but a pain on a sunny day.

 

[MIflyer]

That's surely a digital rendering and not the final configuration of the aircraft?

One of the advantages of putting the engines back that far is that with a naturally aft CG the tail surfaces have to provide less down-force or "negative lift" and can be smaller. Canard aircraft get rid of the down force entirely.

 

[XBe02Drvr]

One of the advantages of putting the engines back that far is that with a naturally aft CG the tail surfaces have to provide less down-force or "negative lift" and can be smaller. Canard aircraft get rid of the down force entirely.

But that aft mounted wing would make the CG super sensitive to cabin load. Best argument for a canard I've ever seen.

 

[MIflyer]

But that aft mounted wing would make the CG super sensitive to cabin load. Best argument for a canard I've ever seen.

Key question relative to W&B is, 'Where did they put the 10 tons or so of batteries that thing must need?"

And I wonder how much air they get over the elevator from those props? That could reduce the required size of the surface quite a bit. For jets I would say "almost none" but those fans spread it out a lot more.

Putting the fans back there also means the amount of surface area that is subjected to the turbulent draggy air from the props is greatly reduced. The Ercoupe was designed to deliberately get the nosewheel out of the prop blast for that reason and a streamline fin was added to the nose strut to reduce the drag for the portion that has to be in the prop blast.

 

[SaparotRob]

Key question relative to W&B is, 'Where did they put the 10 tons or so of batteries that thing must need?"

And I wonder how much air they get over the elevator from those props? That could reduce the required size of the surface quite a bit. For jets I would say "almost none" but those fans spread it out a lot more.

Putting the fans back there also means the amount of surface area that is subjected to the turbulent draggy air from the props is greatly reduced. The Ercoupe was designed to deliberately get the nosewheel out of the prop blast for that reason and a streamline fin was added to the nose strut to reduce the drag for the portion that has to be in the prop blast.

I recently watched a YouTube video on the history of the Ercoupe. It was far more interesting than I expected. Very clever little airplane!

 

[gumbyk]

Putting the fans back there also means the amount of surface area that is subjected to the turbulent draggy air from the props is greatly reduced. T

But the props are working in the turbulent air coming off the wing, which would have to hurt their efficiency.

 

[XBe02Drvr]

But the props are working in the turbulent air coming off the wing, which would have to hurt their efficiency.

Notice they are mounted high relative to the wing, and if you ever watched a smokestream wind tunnel you know the wing turbulence departs in the form of downwash behind the trailing edge. Shouldn't be a problem until you get into a full stall, but then a sudden application of power could enhance the elevators' effectiveness enough to keep the plane in deep stall in the case of a panicked pilot pulling on the yoke. Remember the "tee tailed terror" flap with some of the early jetliners back in the 60s and 70s? (727, HP Trident, DC9, BAC111, VC10 and the deep stall phenomenon)

 

[XBe02Drvr]

Key question relative to W&B is, 'Where did they put the 10 tons or so of batteries that thing must need?

Doesn't matter. They're a fixed weight, so can be anywhere. I would consider distributing them inside the wing to reduce structural weight. The variable weights need to be near the center of lift. With the large downforce requirement on the tail, pitch trim will be super sensitive to power changes. Time for a canard.

 

[SaparotRob]

Notice they are mounted high relative to the wing, and if you ever watched a smokestream wind tunnel you know the wing turbulence departs in the form of downwash behind the trailing edge. Shouldn't be a problem until you get into a full stall, but then a sudden application of power could enhance the elevators' effectiveness enough to keep the plane in deep stall in the case of a panicked pilot pulling on the yoke. Remember the "tee tailed terror" flap with some of the early jetliners back in the 60s and 70s? (727, HP Trident, DC9, BAC111, VC10 and the deep stall phenomenon)

I like the t-tails look and the VC-10 and 727 are my number 2 and 3 fave airliners.
I learned there were problems with t-tails. Might have been mentioned in the book The President's Plane Is Missing. Now I know.

 

[XBe02Drvr]

I learned there were problems with t-tails. Might have been mentioned in the book The President's Plane Is Missing.

For those of you who may not have been around in those days, it was discovered after these planes were in service that they were capable of getting into a steady state deep stall with a high sink rate that was extremely difficult to recover from. Flight crews weren't trained to deal with this unheard-of condition, leading to some gruesome accidents.
The expectation in conventional aircraft is that turbulent detached airflow from the stalled wing would reduce the tail's downforce authority, resulting in a pitch down reduction in angle of attack. With the tee tails this wasn't working as expected, as the tail was staying in smoother air and not suffering enough loss of authority to bring about the desired pitch down. Thus trim or pilot inputs would hold the plane in a partial stall while a high sink rate set in deepening the stall and eventually blanking the stabilizers/elevators to the point that even aggressive application of down elevator would not reduce AoA. The high AoA and turbulent air intake also tempted engines to go into compressor stalls or flame out. This was especially lethal when the plane was loaded near its aft CG limit.
More aggressive stick shakers and stick pushers, plus bringing the aft CG limits forward a bit, plus intensive remedial training were, I believe, the corrective measures of choice for these planes.

 

[MIflyer]

Flight crews weren't trained to deal with this unheard-of condition, leading to some gruesome accidents.

V-22