New Electric Motorglider-Birdy

On Thursday, August 13, 2020 at 2:30:46 PM UTC-4, Waveguru wrote:
Are there any performance figures anywhere? I looked around but could not find any.

Boggs

Go here and scroll down:
https://ebirdycom.files.wordpress.co...birdyx2019.pdf

Uli
'AS'

On Thursday, August 13, 2020 at 2:38:28 PM UTC-6, AS wrote:
On Thursday, August 13, 2020 at 2:30:46 PM UTC-4, Waveguru wrote:
Are there any performance figures anywhere? I looked around but could not find any.

Boggs

Go here and scroll down:
https://ebirdycom.files.wordpress.co...birdyx2019.pdf

Uli
'AS'

40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit limiting for anything but purely relaxed recreational flying.

John Foster wrote on 8/13/2020 7:02 PM:
On Thursday, August 13, 2020 at 2:38:28 PM UTC-6, AS wrote:
On Thursday, August 13, 2020 at 2:30:46 PM UTC-4, Waveguru wrote:
Are there any performance figures anywhere? I looked around but could not find any.

Boggs

Go here and scroll down:
https://ebirdycom.files.wordpress.co...birdyx2019.pdf

Uli
'AS'

40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit limiting for anything but purely relaxed recreational flying.

With a max wing loading of 34 kg/m2, 200 kph will have you coming down at a rapid
rate, so it's not the limiting factor for flying fast.

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit limiting
for anything but purely relaxed recreational flying.


What do you seriously thinking its aimed for?? -winning the Open Class
World Championships?

On Friday, August 14, 2020 at 8:00:04 AM UTC-6, Paul T wrote:
40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit limiting
for anything but purely relaxed recreational flying.


What do you seriously thinking its aimed for?? -winning the Open Class
World Championships?

I'm not sure how much it costs new. But I'm sure that for the same money you can get an older and much better performing glider that you could grow into that you COULD eventually race in, if you wanted to, or work on records, or some other performance related soaring activity.

John Foster wrote on 8/14/2020 1:40 PM:
On Friday, August 14, 2020 at 8:00:04 AM UTC-6, Paul T wrote:
40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit limiting
for anything but purely relaxed recreational flying.


What do you seriously thinking its aimed for?? -winning the Open Class
World Championships?

I'm not sure how much it costs new. But I'm sure that for the same money you can get an older and much better performing glider that you could grow into that you COULD eventually race in, if you wanted to, or work on records, or some other performance related soaring activity.

In the US, it can be raced competitively in the 13.5M class and the Sports Class.
I don't know how competitive it would be in either class, but I'm guessing it
would be at least "adequate". And, there are plenty of records to work for: the
SSA currently lists over 32 pending or confirmed records in the US in the last 6
months for the 13.5M class, and some of those flights also qualified for records
in Sports and Std classes.

Clearly, though, the goal was not racing, but a lightweight, low-cost
self-launcher that is easy to use. The UL ("ultralight") designation is important
in Europe, as it provides licensing and maintenance requirements that are less
onerous than other classes, but is irrelevant in the USA.

I just realized a benefit of the oddly rear mounted propeller: It can be
significantly bigger than the current FES propellers, at 1.3M versus 1.0M
diameter. That's a 70% increase in swept area, which should allow a more efficient
propeller to be used.


--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

I think it's an excellent concept. Besides being a more efficient prop, it's also a fully protected prop that's not susceptible to nose over. I suppose to 'clear prop' and start it, you might hold a mirror up to make sure there's nobody back there to wack.

You do understand that this is more like 3-axis rigid wing hangglider than real glider? 120 kg empty with 3-6 kWh of batteries gives you half the structual weight of normal glider.

At 20:40 14 August 2020, John Foster wrote:
On Friday, August 14, 2020 at 8:00:04 AM UTC-6, Paul T wrote:
40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit
limiting
for anything but purely relaxed recreational flying.

=20
What do you seriously thinking its aimed for?? -winning the Open
Class=20
World Championships?

I'm not sure how much it costs new. But I'm sure that for the same
money
y=
ou can get an older and much better performing glider that you could
grow
i=
nto that you COULD eventually race in, if you wanted to, or work on
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, or some other performance related soaring activity.


Same could be said about many sailplanes - but its clearly not aimed at
that market is it? -only a fool would think otherwise........

On 8/14/20 2:40 PM, John Foster wrote:
On Friday, August 14, 2020 at 8:00:04 AM UTC-6, Paul T wrote:
40:1 glide ratio sounds nice, but a VNE of 200km/hr seems a bit limiting
for anything but purely relaxed recreational flying.


What do you seriously thinking its aimed for?? -winning the Open Class
World Championships?

I'm not sure how much it costs new. But I'm sure that for the same money you can get an older and much better performing glider that you could grow into that you COULD eventually race in, if you wanted to, or work on records, or some other performance related soaring activity.


On a good flying day with no towplane or towpilot in sight, this thing
would fly circles around a JS-3 sitting on the ground.