On 12/12/20 2:56 PM, Eric Greenwell wrote:
2G wrote on 12/12/2020 12:31 PM:
On Friday, December 11, 2020 at 8:17:42 PM UTC-8,
wrote:
I actually helped put one of those three into a hangar last weekend.
I'm friends with the IA who just inspected it and an acquaintance of
one of the owners who flies it. I've seen it fly twice and he seems
to have a good bit of fun with it.

Here is a review of the Silent 2:
https://www.aviationconsumer.com/ind...ctric-gliders/


My take on it is you can self-launch and do one low save. If you want
to self-retrieve you will need to get an aerotow to maintain a fully
charged battery. Even then, retrieve distance is quoted as cruising at
level flight w/o a headwind. If you have to climb to clear a mountain
range, for example, you will exhaust your batteries and may not even
clear the range. This happened to one pilot at Ely last summer. Faced
with that dilemma, he used his battery capacity to search for a
suitable landing field. He was fortunate and got a weak cell phone
signal to send his situation to fellow pilots back at Ely. They left
the airport in the dark and returned at about 2 am.

Other considerations a
1. Is the launching altitude specified at max gross weight (the GP15
is not)? If not, what is the launch altitude at the weight you will be
flying it? Will you fly with water ballast?
2. How high do you typically launch to where you fly?
3. Do you have hills or mountains that you will have to clear on a
self retrieve?
4. Do you even care about self retrieving?
5. The battery safety at this time has a big question mark (I consider
it unproven and will not fly one).
6. How are you going to recharge the battery on field (you will need a
dedicated 20A circuit). Most remove the batteries and take them to a
suitable circuit at the hangar or motel or home.

Tom

The review was very limited, with no remarks from users of the Silent
Electro. That's important, because the reviewer would have learned that
Silent owners rarely end up 100 miles from home, needing a retrieve.
Shucks, that rarely (once every 5 years?) happens to me, and I fly an
ASH 26E. The Electro's lower performance means the pilot turns around
not as far from home, and ends up needing to retrieve only 50 miles out
while Al is 100 miles out. And, since the pilot knows how much retrieve
distance he has, he can makes his decisions accordingly.

Again, any pilot considering one should definitely talk to owners that
fly them a lot. Jeff Banks is the Electro pilot I know who has had a lot
of good flights in the Parowan/Richfield area, and usually self
launching. Take a look at his OLC logbook for the 2020 season:

https://www.onlinecontest.org/olc-3....t=olc&pi=10497


Tom's remarks are more useful than the review, I think, and point out
that where you fly could make a big difference in the amount of motor
duration you will need. Nevada and Utah are going to be much more
demanding than Kansas and Florida, for example.

One point from Tom's remarks I disagree with: Jeff did not use a
dedicated 20A circuit to charge his batteries while he was at RIchfield,
but just a standard 15A socket in the lounge of the FBO.


I agree the article was not not very in-depth.

Interesting that the June 4 flight had a landout after a meandering
flight, 122 km scoring distance, no points due to late submission. If
he had been in a gas powered glider, it would have been an easy
self-retrieve.

One thing about the electric gliders, battery voltage isn't constant at
all, you are likely to get a couple minutes of good climb rate, then
significantly less with continued motor use.

I'm sure some people have fun flying those things, but others get
frustrated with the lack of power they pack in the batteries. I suppose
there were 17 registered in the U.S. until that Silent 2 went through
the roof in Connecticut, making international news. Apparently you
don't always have as much energy left as the little computer display
says you do.

-Dave