Future of aviation, or flash in the pan??

On Sunday, January 26, 2020 at 9:27:22 AM UTC-8, wrote:
On Saturday, January 25, 2020 at 2:21:06 PM UTC-6, Eric Greenwell wrote:
kinsell wrote on 1/24/2020 9:39 PM:


Why are we talking about electric airplanes instead of electric sailplanes? Even
stodgy Schleicher now has a really nice 18M electric self-launcher at at an
interesting price. It should be very appealing to pilots that want a really good
motorglider without the cost, operating complexity, and maintenance of the
fossil fueled motorgliders.

An the 15M GP15 also looks like a good choice: smaller, lighter, cheaper, but
still very good gliding performance. The miniLak and Silent 2 FES gliders seem
perfect for pilots looking for decent performance and freedom from the tow plane.

So why are we talking about electric airplanes?Â* Sure beats talking about phoney
movies on ballooning in the 1860's, doesn't it?

I see some great similarities between stuffing lithium-cobalt batteries in a
glider and adding an electric motor, and doing the same with a power plane.Â* They
both suffer from limited battery capacity, safety concerns, significant cost, and
charging hassles.Â* Lots more work being done currently on power planes than
gliders.Â* When a Pipistrel Alpha Electro goes for a swim in a cold lake in Norway,
it's hard to tell if that's a power plane or motorglider.

I'm less impressed with the current crop of electric gliders than you are.Â* Couple
of friends got in the very first orders for GP-15's and have been waiting years
for delivery.Â* I keep seeing gliders certified for self-launch taking tows,
because they can self-launch or self-retrieve, but not both.Â* The gas-powered
solutions aren't great, but IMHO better than the electrics, or heaven forbid the
jets.

I know several people WA state that are happy self-launching in their Silent
Electro and miniLaks. The GP15 has been delayed, in part because they are a new
glider company, and in part due the technical difficulties of producing a high
performance, self-launching sailplane. It still has a long order list. And when
Schleicher thinks it time to enter the field, it's not the future anymore. Call
the Schleicher dealer and place your order for one, before the list gets too long.

--
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

Eric, I did just that, requested a quote for the AS 34. Full system price with trailer delivered to the US was just under $200k. That's really a lot for a non-flapped 18 m "Standard Class" glider that was developed over 25 years ago. I don't agree with you that this is "affordable". I also heard that sales are not so hot, you can get one this summer. If they had put this into a '29 or '33 I might be interested.

It might be more interesting, and with an ultimately larger market, to sell an electric retrofit for the AS self launchers. The engineering and installation should be relatively simple. If my Wankel seizes I'd be tempted to do that, rather than replace it at great cost.

If you step by the SSA convention you will see one

On Sunday, January 26, 2020 at 7:14:12 PM UTC-5, jfitch wrote:
...an electric retrofit for the AS self launchers.
The engineering and installation should be relatively simple.

Um, not on this planet.

The engineering and installation should be relatively simple.

Um, not on this planet.

"Designing an airplane is easy, if you don't know how."

On Monday, January 27, 2020 at 11:20:34 PM UTC-5, wrote:
The engineering and installation should be relatively simple.

Um, not on this planet.

"Designing an airplane is easy, if you don't know how."

Very nice Mark!
For those of you who don't know the reference, here's the source:

https://evtol.news/wp-content/upload...xpo-2019-5.pdf

(slide 27)

Amusing to see him hold it up next to the Lilienthal quote (which I've also seen more often in slightly different version and attributed to others): "To invent an aircraft is nothing. To build one is something. To fly is everything."

A recent example: https://www.forbes.com/sites/jeremyb.../#646fe858ab40

On Monday, January 27, 2020 at 7:04:36 PM UTC-8, Dave Nadler wrote:
On Sunday, January 26, 2020 at 7:14:12 PM UTC-5, jfitch wrote:
...an electric retrofit for the AS self launchers.
The engineering and installation should be relatively simple.

Um, not on this planet.

Perhaps you did not catch the "relatively"? Engine bay is already there, the doors are there, it is engineered and built for the weight, the extraction mechanism is already there, even the prop and boom. So yes, "relatively simple" compared to retrofitting say an ASW27, which is being done, and has none of those things.

I am not a stranger to complexity, or aircraft design.

On Tuesday, January 28, 2020 at 1:48:48 AM UTC-5, jfitch wrote:
On Monday, January 27, 2020 at 7:04:36 PM UTC-8, Dave Nadler wrote:
On Sunday, January 26, 2020 at 7:14:12 PM UTC-5, jfitch wrote:
...an electric retrofit for the AS self launchers.
The engineering and installation should be relatively simple.

Um, not on this planet.

Perhaps you did not catch the "relatively"? Engine bay is already there, the doors are there, it is engineered and built for the weight, the extraction mechanism is already there, even the prop and boom. So yes, "relatively simple" compared to retrofitting say an ASW27, which is being done, and has none of those things.

I am not a stranger to complexity, or aircraft design.

"How hard could it be"
That depends.
Certainly if you already have an engine bay, and lift mechanism, you have a great start. No engineering the hole in the fuselage, etc.
If you have a proven drive system, much of the next part is more easily accomplished.
2 meaningful issues with converting the later Schleicher ships:
1) Where do the batteries go? Engine bay has some room but CG possibilities become limited. Wing installation would most certainly involve major stuff in any of the hard tank wings. Support and service access are non trivial.
This is the major task on the '34. The rest is mostly transplanting proven motor and drive into the '34 from the 32E.
2) Engine bay size matters because it limits available prop diameter and this is a real issue in getting performance out of the drive.

I have some practical experience with this as I am now starting test flying of an ASW-24E that has been converted to electric.

How hard could it be?

The largest barrier is a lack of proven motor/ controller systems to incorporate into a project.
FWIW
UH

wrote on 1/28/2020 6:59 AM:
Perhaps you did not catch the "relatively"? Engine bay is already there, the
doors are there, it is engineered and built for the weight, the extraction
mechanism is already there, even the prop and boom. So yes, "relatively
simple" compared to retrofitting say an ASW27, which is being done, and has
none of those things.

I am not a stranger to complexity, or aircraft design.
"How hard could it be" That depends. Certainly if you already have an engine
bay, and lift mechanism, you have a great start. No engineering the hole in the
fuselage, etc. If you have a proven drive system, much of the next part is more
easily accomplished. 2 meaningful issues with converting the later Schleicher
ships: 1) Where do the batteries go? Engine bay has some room but CG
possibilities become limited. Wing installation would most certainly involve
major stuff in any of the hard tank wings. Support and service access are non
trivial. This is the major task on the '34. The rest is mostly transplanting
proven motor and drive into the '34 from the 32E. 2) Engine bay size matters
because it limits available prop diameter and this is a real issue in getting
performance out of the drive.

There is a significant size compartment between the engine bay and gear wheel that
could hold batteries, and more space in the gear well that has the 16 liter fuel
tank. Some batteries can be placed in the engine bay, as an electric motor is
lighter than the Wankel and all it's accessories (starter, muffler, oil tank, etc).

--
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

On Tuesday, January 28, 2020 at 6:59:56 AM UTC-8, wrote:
On Tuesday, January 28, 2020 at 1:48:48 AM UTC-5, jfitch wrote:
On Monday, January 27, 2020 at 7:04:36 PM UTC-8, Dave Nadler wrote:
On Sunday, January 26, 2020 at 7:14:12 PM UTC-5, jfitch wrote:
...an electric retrofit for the AS self launchers.
The engineering and installation should be relatively simple.

Um, not on this planet.

Perhaps you did not catch the "relatively"? Engine bay is already there, the doors are there, it is engineered and built for the weight, the extraction mechanism is already there, even the prop and boom. So yes, "relatively simple" compared to retrofitting say an ASW27, which is being done, and has none of those things.

I am not a stranger to complexity, or aircraft design.

"How hard could it be"
That depends.
Certainly if you already have an engine bay, and lift mechanism, you have a great start. No engineering the hole in the fuselage, etc.
If you have a proven drive system, much of the next part is more easily accomplished.
2 meaningful issues with converting the later Schleicher ships:
1) Where do the batteries go? Engine bay has some room but CG possibilities become limited. Wing installation would most certainly involve major stuff in any of the hard tank wings. Support and service access are non trivial.
This is the major task on the '34. The rest is mostly transplanting proven motor and drive into the '34 from the 32E.
2) Engine bay size matters because it limits available prop diameter and this is a real issue in getting performance out of the drive.

I have some practical experience with this as I am now starting test flying of an ASW-24E that has been converted to electric.

How hard could it be?

The largest barrier is a lack of proven motor/ controller systems to incorporate into a project.
FWIW
UH

So how hard was it, for a very skilled and practiced professional? Will you be publishing an article in Soaring, a pre-writeup on RAS? Sounds very interesting.

On Tuesday, January 28, 2020 at 6:59:56 AM UTC-8, wrote:
On Tuesday, January 28, 2020 at 1:48:48 AM UTC-5, jfitch wrote:
On Monday, January 27, 2020 at 7:04:36 PM UTC-8, Dave Nadler wrote:
On Sunday, January 26, 2020 at 7:14:12 PM UTC-5, jfitch wrote:
...an electric retrofit for the AS self launchers.
The engineering and installation should be relatively simple.

Um, not on this planet.

Perhaps you did not catch the "relatively"? Engine bay is already there, the doors are there, it is engineered and built for the weight, the extraction mechanism is already there, even the prop and boom. So yes, "relatively simple" compared to retrofitting say an ASW27, which is being done, and has none of those things.

I am not a stranger to complexity, or aircraft design.

"How hard could it be"
That depends.
Certainly if you already have an engine bay, and lift mechanism, you have a great start. No engineering the hole in the fuselage, etc.
If you have a proven drive system, much of the next part is more easily accomplished.
2 meaningful issues with converting the later Schleicher ships:
1) Where do the batteries go? Engine bay has some room but CG possibilities become limited. Wing installation would most certainly involve major stuff in any of the hard tank wings. Support and service access are non trivial.
This is the major task on the '34. The rest is mostly transplanting proven motor and drive into the '34 from the 32E.
2) Engine bay size matters because it limits available prop diameter and this is a real issue in getting performance out of the drive.

I have some practical experience with this as I am now starting test flying of an ASW-24E that has been converted to electric.

How hard could it be?

The largest barrier is a lack of proven motor/ controller systems to incorporate into a project.
FWIW
UH

The engine bay is quite large, and would be unoccupied by motor and muffler, and requires about 170 lbs to achieve normal W/B. The space in the wheel well used for the fuel tanks is also available, though the volume in the engine bay alone is probably enough. In my post I suggested that Schleicher do this (instead of the 34), they have already developed the motor/battery/controller for use in other gliders, so that is not a barrier for them. Thus "relatively simple". I'll stand by that characterization.