Which sustainer system would you chose for your sailplane?

On Thursday, January 7, 2016 at 8:45:05 AM UTC-5, Dave Walsh wrote:
At 01:24 07 January 2016, Casey wrote:
For the cost I would get a self launcher vice a sustainer. I
know the Lak
=
17 FES can launch but I think they were originally and
maybe still calling
=
it a sustainer. For that kind of money I would want the
glider
manufacture=
to endorse launch. I think the Mini Lak and the Silent
endorse launch.
I=
would hate to have over 100k in a glider and self launch
and something go
=
wrong and insurance not pay off because I was launching a
sustainer.
Pleas=
e correct me if I'm wrong.

I do like the ease of use of the FES and think its great


It's quite simple: it's either a self launch sailplane or not:
look at the specifications.
Additionally you are mixing Ultralights (the Silent) with
conventional sailplanes (the LAK17B FES). My understanding
is that is NOT legal, in Europe, to self launch the LAK17BFES
(or indeed any other true "sustainer" sailplane). It's been
done of course but it makes no sense with an electric power
plant, what little battery power you started with has now
gone so you have no useful sustainer performance left. Why
would you even think that's a good idea?

The Silent Electro is a different (lighter) animal, designed as
a self launch. You could launch to a modest height and have
some sensible retrieve capability but you're sitting in a
fragile (compared to a modern sailplane) structu lower Va,
lower Vne etc. It's very nicely built and a joy to rig. It's not
much cheaper than a LAK17BFES......choices.

That's kinda my point.

But if I was a manufacture of anything. I would not come out with my best to begin with. I would come out with a sustainer and let the high rollers buy. Then come out with a more powerful self launcher. The high rollers will sell their sustainers for the self launchers. I bet auto manufactures do this as well as other companies.

I realize the specs of the Lak and Silent 2 Electro. Same system in 15m gliders. I would not call the Silent a ultralight with an empty wt of 452 lbs and VNe 137 mph. I would call it a 13.5m conventional. Just like I would not classify a 15m with an 18m or 20m. All are different. Now the Sparrow Hawk I would classify as Ultralight.

And for the sake of discussion I can substitute the GP 14 VELO for the Silent 2. Same VNe as and empty wt as Lak 17. http://www.gpgliders.com/gp-14-e-velo

13.5m class= Alisport Silent, GP 14 Velo, Mini Lak, Albastar AS 13.5,

And you are right...Its a sustainer or self launcher. Just like its a 13.5m or 15m or 18m or 20m, flapped or not.

I'm just saying I would not spend the money on a sustainer if I could get a self launcher. Someone that lives closer to a tow would choose differently.

Jets may be more thirsty than 2 stroke sustainers but the extra power and speed makes the additional fuel cost pale into insignificance - even more so when you think of it a a proportion of the capital and running costs of a new glider.

Electric will obviously evntually win out but battery technology is advancing only slowly compared to other technologies and the capital costs remain expensive. I don't know the cost of FES batteries but I reckon I could buy around 8000 litres of jet fuel for the cost of a set of Antares batteries - maybe more. I used about 100 litres last summer including a lot of testing rather than retrieve use.

( But I do rather fancy the GP14E Velo!)

Not sure I'd agree with your thinking on the marketing of the
sustainer and the self-launch glider (ignoring the Ultralights;
incidentally the Silent Electro is an ultralight in Europe).

As a long time owner of several self-launch sailplanes I'd say
self launch buyers and sustainer buyers tend to have different
priorities. Self launchers are heavier, costlier and more
complex: unless you do a lot of flying (say 200 hours per
year) their real running costs are more than a conventional
sailplane. Plus their glide performance, especially in weak
conditions, is worse: this is a real drawback. And when they
breakdown the costs can be truly fantastic: look up the cost of
rebuilding a Solo or rotary engine or, worse, buying a new
engine. Against this is the hard to quantify "independence" and
the ability to get home (usually). Remember all self-launch
owners are complete masters of that branch of accounting
known as "man maths".

Sustainer owners and buyers are a much saner bunch; lower
costs, lighter weight, minor (or nil) performance loss and you
still get home (usually). Not sure many go from sustainer to
self launch? I can see self launch owners going to FES though.
Dave Walsh

While I hear the advantage of other type of power - I think more people are comfortable throwing a switch, than firing up a jet or hoisting a boom. And I have never been around any engine that uses fuel and did not smell bad.

Plus you have to explain to your wife that you just purchased a jet, when she thought you were going to fly around the airport safe and sound lol

I still think pilots who are real racing pilots will go powerless and the vast majority of us would be more comfortable flipping a switch even if a Jet has that 007 appeal.

WH1

At 19:35 07 January 2016, wrote:
Jets may be more thirsty than 2 stroke sustainers but the
extra power and
s=
peed makes the additional fuel cost pale into insignificance
- even more
so=
when you think of it a a proportion of the capital and
running costs of a
=
new glider.

Electric will obviously evntually win out but battery
technology is
advanci=
ng only slowly compared to other technologies and the
capital costs remain
=
expensive. I don't know the cost of FES batteries but I
reckon I could
bu=
y around 8000 litres of jet fuel for the cost of a set of
Antares
batteries=
- maybe more. I used about 100 litres last summer
including a lot of
test=
ing rather than retrieve use.

( But I do rather fancy the GP14E Velo!)

Well either you are buying really expensive Jet fuel or you
know a source of really cheap Antares batteries; I'd say you
might buy 20,000+ litres of Jet fuel.

On Sunday, September 23, 2012 at 1:55:26 AM UTC-4, Luka Žnidarši� wrote:
Dear gliderpilots!

Manufacturers are not completely sure which is the way to go. So here you can vote for your favorite sustainer system:

http://www.front-electric-sustainer.com/voting.php

Thank you,

Luka

How about an electric powered shrouded fan that produces 50 lbs of thrust!

https://www.youtube.com/watch?v=VBkkJdwF2Lo

On Thursday, January 7, 2016 at 8:45:05 AM UTC-5, Dave Walsh wrote:
My understanding
is that is NOT legal, in Europe, to self launch the LAK17BFES
(or indeed any other true "sustainer" sailplane).

The MINI LAK 13.5 is being developed as a self-launch LSA (European spec LSA). I understand that it would get a Self-launch Experimental Glider Airworthiness Certificate in the USA. It has a lowish pilot weight limitation of 87 kg (192 lbs). It is less expensive than the Silent Electro II FES self-launch. Blanik America has a brochure and quotes a price.

On Thursday, January 7, 2016 at 10:45:11 PM UTC-5, son_of_flubber wrote:

The MINI LAK 13.5 is being developed as a self-launch LSA (European spec LSA).

Correction: They're aiming for Ultralight in Europe (less than 300 kg all up weight).

On Thursday, 27 September 2012 00:06:31 UTC+2, wrote:
For me electrical sustainer in a glider is the perfect solution. It links in to the spirit of the sport, beter than a turbine. But the propellor on the nose feels slightly off.... Especially when you consider the bugwipergarages becoming standard on the topsailplanes. We are spending more and more on reducing drag. Then this minor addition feels going against the flow. Why not a small pilon whit this nice foldable propellor you have engineered? Or am I the only one who has this uncomfortable feeling?

How about FES in an EDF (electric ducted fan) configuration instead of pylon mounted FES? The EDF could be mounted in the fuselage with doors than open and close for the inlet and exhaust.
Would this make any sense or be simpler than a pylon mounted system?
Would a smaller prop size make it less efficient and impractical?
The one advantage would be the removal of most of the pitching issue associated with pylon mounted systems.

If I had the money for a self launcher or sustainer equipped glider it would be FES due to simplicity, reliability and safety.
From a safety perspective I presume a battery fire would tend to be more isolated in a crash whereas with combustible fuel you and the glider could become engulfed in flames within seconds as fuel is splashed around.
As battery and fuel cell technology advances, alternative energy storage upgrades could be a possibility without having to purchase another glider.
I don't like the smell of gasoline or jet fuel nor the complexity with things that operate at high temperatures and need to be maintained regularly. A brushless electric motor can literally run for years with a decent set of bearings. That means less hassle and maybe lower maintenance costs over the long run depending on the battery technology being used.

A sustainer option would suite me perfectly. I don't need to operate autonomously and a winch launch to 1500 feet is cheap ($4.70 USD) and preserves power for when I may need it.

Approximate prices as of spring 2015...

D2c 18m - 68k Euro
D2cT 18m - 85k Euro
D2c FES 18m - 93k Euro

All plus VAT.
All plus loads of "Options"

By the time you've added a trailer & sensible instrument fit you're looking
at around 150k Euro inc VAT, so difference between "traditional" turbo &
FES is less than the variation in exchange rates from week to week (Or day
to day at the moment!)

KN

At 16:44 07 January 2016, Dan Marotta wrote:

I haven't compared that price to the price difference on a new glider
with and without a FES but I would guess that it was in line with buying
a new glider. Travel, shipping, and lodging costs are considerable for
the duration of the installation.