Ventus 2cxa with FES

At 00:10 15 April 2014, Steve Koerner wrote:
From a competition pilot point of view there would have to be a
small drag
=
penalty and a weight penalty. But both of those would seem
to be pretty
sm=
all in comparison to the competitive benefit that arises from the
ability
t=
o stick to the course line and never have to be distracted by
the need to
d=
eviate towards a landing option. I don't have experience to
know, but I'm
=
suspecting that the reliability of the FES might be sufficient
that one
cou=
ld drive it straight into the boonies then flip the switch only at
the
last=
minute -- wouldn't that be exciting? You certainly can't do
that with a
g=
as engine.


But if you are 100km away from your airfield, especially if you
used your battery for take off, there will be little or no use of
FES.
I like the idea, but sorry, with current Li-ion batteries with max
150Wh/kg, this is not very promising technology. I am waiting for
Li-S, or Li-Air cells, then we can talk seriously about FES.
Regards
Wolf
http://youtu.be/WCej1kZInZk

As the saying goes....

"The perfect is the enemy of the good..."

There is no "perfect," but I do believe the FES is a tremendous technical advancement which can really add to one's soaring safety and enjoyment.

I have been very fortunate to own a LAK-17B FES for the past two years and it is truly an outstanding ship with a very reliable sustainer. I do take aero tows, so I get to save every "volt" in the event I need to use the FES for a self retrieve. If it is needed the FES can get me home or at least to an airport and the maximum range of up to 100KM works out just fine. Also, as battery technology improves, new batteries can be installed and the range of the FES will also improve. I can wait for those future battery improvement, but the FES design has been around for five years and IMHO, is a proven design. After over 40 years in soaring, I was not going to wait for the "perfect..."

Now, if one wants a self-launcher the FES is probably not the right choice (unless one wants to go with the FES in a lighter glider like the Silent 2 Electro), but for a sustainer, the FES is truly is an excellent solution!

Now, be safe out there!
Thanks - Renny




On Monday, April 14, 2014 6:26:24 PM UTC-6, Wolf Aviator wrote:
At 00:10 15 April 2014, Steve Koerner wrote:

From a competition pilot point of view there would have to be a

small drag

=

penalty and a weight penalty. But both of those would seem

to be pretty

sm=

all in comparison to the competitive benefit that arises from the

ability

t=

o stick to the course line and never have to be distracted by

the need to

d=

eviate towards a landing option. I don't have experience to

know, but I'm

=

suspecting that the reliability of the FES might be sufficient

that one

cou=

ld drive it straight into the boonies then flip the switch only at

the

last=

minute -- wouldn't that be exciting? You certainly can't do

that with a

g=

as engine.





But if you are 100km away from your airfield, especially if you

used your battery for take off, there will be little or no use of

FES.

I like the idea, but sorry, with current Li-ion batteries with max

150Wh/kg, this is not very promising technology. I am waiting for

Li-S, or Li-Air cells, then we can talk seriously about FES.

Regards

Wolf

http://youtu.be/WCej1kZInZk

Dne torek, 15. april 2014 02:26:24 UTC+2 je oseba Wolf Aviator napisala:
At 00:10 15 April 2014, Steve Koerner wrote:

From a competition pilot point of view there would have to be a

small drag

=

penalty and a weight penalty. But both of those would seem

to be pretty

sm=

all in comparison to the competitive benefit that arises from the

ability

t=

o stick to the course line and never have to be distracted by

the need to

d=

eviate towards a landing option. I don't have experience to

know, but I'm

=

suspecting that the reliability of the FES might be sufficient

that one

cou=

ld drive it straight into the boonies then flip the switch only at

the

last=

minute -- wouldn't that be exciting? You certainly can't do

that with a

g=

as engine.





But if you are 100km away from your airfield, especially if you

used your battery for take off, there will be little or no use of

FES.

I like the idea, but sorry, with current Li-ion batteries with max

150Wh/kg, this is not very promising technology. I am waiting for

Li-S, or Li-Air cells, then we can talk seriously about FES.

Regards

Wolf

http://youtu.be/WCej1kZInZk

As mentined above already at Ventus we have enough margin of max weight of non lifting parts, so that we were able to integrate bigger battery compartment box, so that we can fit inside bigger battery packs (50kg instead of standard 32kg). Range of 180km of level flight or 2000m altitude gain is more than sufficient!

Regards,

Luka

Luka, can it be installed on a Schleicher, in particular ASW27?

Ramy

Dne torek, 15. april 2014 19:18:18 UTC+2 je oseba Ramy napisala:
Luka, can it be installed on a Schleicher, in particular ASW27?



Ramy

From techical point of view, I am sure we could find a solution. However in Europe under EASA is currently not possible, if there is no support from holder of Type Certificate. For USA under experimental might be possible, but we need a glider in our workshop for retrofit.

Regards,

Luka

Dne torek, 15. april 2014 02:10:45 UTC+2 je oseba Steve Koerner napisala:
From a competition pilot point of view there would have to be a small drag penalty and a weight penalty. But both of those would seem to be pretty small in comparison to the competitive benefit that arises from the ability to stick to the course line and never have to be distracted by the need to deviate towards a landing option. I don't have experience to know, but I'm suspecting that the reliability of the FES might be sufficient that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting? You certainly can't do that with a gas engine.

You are right, at FES you can start engine last minute (1 second to full power), and it is exciting. Totaly different way of flying!

Regards,

Luka

On Monday, April 14, 2014 5:10:45 PM UTC-7, Steve Koerner wrote:
From a competition pilot point of view there would have to be a small drag penalty and a weight penalty. But both of those would seem to be pretty small in comparison to the competitive benefit that arises from the ability to stick to the course line and never have to be distracted by the need to deviate towards a landing option. I don't have experience to know, but I'm suspecting that the reliability of the FES might be sufficient that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting? You certainly can't do that with a gas engine.

" that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting?"

Deadly exciting, actually....

On Tuesday, April 15, 2014 11:41:22 AM UTC-7, jfitch wrote:
On Monday, April 14, 2014 5:10:45 PM UTC-7, Steve Koerner wrote:

From a competition pilot point of view there would have to be a small drag penalty and a weight penalty. But both of those would seem to be pretty small in comparison to the competitive benefit that arises from the ability to stick to the course line and never have to be distracted by the need to deviate towards a landing option. I don't have experience to know, but I'm suspecting that the reliability of the FES might be sufficient that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting? You certainly can't do that with a gas engine.



" that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting?"



Deadly exciting, actually....

I sort of figured someone would snipe to that effect. So, jfitch, what is your reasoning that makes it 'deadly'?

Are there any known cases when an FES was intended to be initiated but failed to do so in flight?

It would seem to me that the FES has much going for it in terms of its potential for very high reliable operation. That would be the fact of no boom to raise and the fact that the power plant is an electric motor.

Single engine airplane pilots think nothing of routinely flying in the boonies with no landing alternate available to them. That contrasts with an FES glider pilot who might put himself into that situation only rarely.

I think all of us have had plenty of experience with both electric motors and gas motors and know the former to be vastly more reliable. Yet power pilots treat their gas engines as reliable enough to bet their life on. I'm suspecting that a reasoned glider pilot who has tested his FES startup many times in non-threatening circumstances would arrive at the same determination. The interesting part is that yields a significant advantage in competition.

From a general flying point of view, here in the UK we're never really that
far from an airfield.
The "limited" range still means you can get away from a Farmer's field to a
true airfield where the reception is likely to be better & chance of
breaking the glider much reduced.
As a Discus Turbo owner I'm very aware of the failure rate (mostly pilot
induced) of the current turbos.
I can't believe any electric sustainer could be less reliable

FES certainly appeals to me

Regards

KN

On Tuesday, April 15, 2014 1:32:16 PM UTC-7, Steve Koerner wrote:
On Tuesday, April 15, 2014 11:41:22 AM UTC-7, jfitch wrote:

On Monday, April 14, 2014 5:10:45 PM UTC-7, Steve Koerner wrote:



From a competition pilot point of view there would have to be a small drag penalty and a weight penalty. But both of those would seem to be pretty small in comparison to the competitive benefit that arises from the ability to stick to the course line and never have to be distracted by the need to deviate towards a landing option. I don't have experience to know, but I'm suspecting that the reliability of the FES might be sufficient that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting? You certainly can't do that with a gas engine.







" that one could drive it straight into the boonies then flip the switch only at the last minute -- wouldn't that be exciting?"







Deadly exciting, actually....



I sort of figured someone would snipe to that effect. So, jfitch, what is your reasoning that makes it 'deadly'?



Are there any known cases when an FES was intended to be initiated but failed to do so in flight?



It would seem to me that the FES has much going for it in terms of its potential for very high reliable operation. That would be the fact of no boom to raise and the fact that the power plant is an electric motor.



Single engine airplane pilots think nothing of routinely flying in the boonies with no landing alternate available to them. That contrasts with an FES glider pilot who might put himself into that situation only rarely.



I think all of us have had plenty of experience with both electric motors and gas motors and know the former to be vastly more reliable. Yet power pilots treat their gas engines as reliable enough to bet their life on. I'm suspecting that a reasoned glider pilot who has tested his FES startup many times in non-threatening circumstances would arrive at the same determination. The interesting part is that yields a significant advantage in competition.

While an electric motor *may* be more reliable than gas, you are still starting a stopped motor, unfolding a folded prop, etc. I don't know a single power plane pilot who would knowingly fly into rocks or over water *with the engine stopped*, figuring on starting it when the trees got close.

This has been proposed endlessly as an advantage motor gliders have over pure gliders, the ability to fly low over unlandable terrain. I don't fly mine that way and I don't know of anyone that does. My engine starts are always over a landable field, the advantage is that the inconvenience of a ground retrieve is eliminated in most cases.

Now, there are competition pilots who will willingly fly over unlandable terrain with no motor at all, just as there are those that will cheat in various ways. Such a pilot might abuse the capability. It seems to be rarely said that one of the reasons many pilots do not engage in competition is that risk is rewarded.