New Alice Starts Taxi Testing

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rv6ejguy

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Looks like they've changed motor location substantially from the initial design. V tail and conventional gear is gone too.
 
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rv6ejguy

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If they have increased battery size/weight, payload or performance will suffer from the earlier predictions. How do they de-ice this thing or is it a VFR only technology demonstrator at this point? What kind of crosswinds will it be able to safely handle with that short gear and long wings? How long to re-charge it?

While it is MUCH more practical than the original having the motors on the wing tips (what engineer could ever think that would work or be certified?), I see lots of potential problems in meeting design goals still.
 
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rv6ejguy

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I've crunched a few numbers here from specs:

Max flight time at full power (no reserves)- 39 mins
Max flight time at 50% power- 1.3 hours
Range at average 50% power- 286NM (Not including higher power and lower speed in the climb)

These figures don't include using the battery for anything else other than propulsion and using 100% of battery capacity.

Not sure how they'll heat it, de-ice it or pressurize it. Those things all take power too.

Almost for sure, the numbers will be worse than above in real life.

Better have some impressive battery monitoring and cooling for these power levels...

I can only guess that their engineers use some funny math here to arrive at their range numbers...
 
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Vigilant1

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Almost for sure, the numbers will be worse than above in real life.
Yeah, it looked that way to me, too. Add in required VFR or IFR reserves/fuel for a missed approach, climb, cruise to divert location etc and ...

If the numbers are right, the silver lining is that they'll get a priority for landing wherever they go. They'll be declaring an emergency for fuel before the gear is up.
 

rv6ejguy

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If we compare to other old 10 seat pressurized designs like a Conquest or Merlin, it is 40-80 knots slower and has about 1/10th of the range. Hardly replacements for those aircraft or missions they can fly. In reality, this will only be flying 100-150NM legs since you can't run the full capacity out of these batteries or they'll be destroyed in short order.

Doesn't pass the initial smell test here...
 

Vigilant1

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Trivial to have differential thrust for yaw control if they're not designing for motor out. This is part 23, not part 25, so if they can substantiate sufficiently high motor reliability they don't necessarily need to design for motor out.
Anybody know how the FAA will treat the battery/battery management system/motors for purposes of redundancy/factor analysis? Having two motors but depending on a single battery, BMS, etc. I'm guessing the manufacturer would need to demonstrate hands-off isolation of critical systems before the FAA would give them credit for redundancy.
 

Victor Bravo

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Am I the only one who just happened to notice that those electric motor nacelles look like they're the perfect shape, and you could just reach up and swap out that electric motor out for a PT-6 in a jiffy (after the greenwashing checks clear and the reality sets in, and they still want to have a useful product to sell corporations and air taxis) ??
 
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addaon

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Anybody know how the FAA will treat the battery/battery management system/motors for purposes of redundancy/factor analysis?

I've had discussions with the FAA on exactly this topic, and would be glad to discuss it offline.

I highly doubt they're using a single battery. I strongly suspect that they're using multiple independent winding sets in each stator, if not multiple stators per shaft. Having worked through this for a part-23-ish 13-motor aircraft, I can state that motor and battery redundancy is not a particularly unapproachable challenge.
 

Vigilant1

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Am I the only one who just happened to notice that those electric motor nacelles look like the'yre the perfect shape, and you could just reach up and swap out that electric motor out for a PT-6 in a jiffy (after the greenwashing checks clear and the reality sets in, and they still want to have a useful product to sell corporations and air taxis) ??
If you zoom into the photo and squint, you can see they have sump drain ports under the present location of the batteries.:)
Forward thinking, these guys are.
 
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tspear

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If we compare to other old 10 seat pressurized designs like a Conquest or Merlin, it is 40-80 knots slower and has about 1/10th of the range. Hardly replacements for those aircraft or missions they can fly. In reality, this will only be flying 100-150NM legs since you can't run the full capacity out of these batteries or they'll be destroyed in short order.

Doesn't pass the initial smell test here...

I think it was CapeAir that stated the average length was 75 miles. There was another one in the Pacific NW which stated the average was closer to 50 miles as the crow flies.

Tim
 

rv6ejguy

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Yes, Harbour Air in BC just completed a passenger carrying flight recently- 45 miles total distance one way. There is a niche market for that over water or challenging terrain but this design can't meet the specs they're saying on current battery technology.
 
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