An interesting trial flight attempt...

Ramy wrote:
Actually, I may try to convince wife it may be cheaper on the long run
to buy a motorglider (or electric glider) then pay for aerotows, but I
need numbers...

And here they are!

If you already own a glider, then YOU may be able to afford a high
performance, self-launching sailplane (SLS)! Let me show you how:

The first thing to realize is the motor is about a $20,000-25,000
premium over a similar used unpowered glider (more if you are buying a
new one). Check the ads for gliders that are available both ways, such
as the PIK20E, Ventus CM, DG-400, and so on. Here's an example of what
it might cost an active pilot living in Seattle, WA, and driving the 150
miles to fly at Ephrata, WA:

Additional costs:

$1250 interest cost on the $25,000 motor purchase @ 5%
100 annual on the motor
300 extra insurance due to higher value with the motor
100 fuel and oil for 40 launches
------
$1750 Total additional costs

Avoided costs:

$1400 40 regular tows at $35/tow
300 3 aero-retrieves at $100 each
100 2 car retrieves plus dinner for crew
-----
$1800 Total avoided costs

Net cost: approximately $Zero

The analysis assumes you fly the exactly same way with the SLS as you
did before it, but as you adapt to the SLS, you will find yourself using
the extra soaring opportunities it provides: flying from airports
without a towplane, or when a towpilot isn't available; flying
cross-country when you otherwise wouldn't, because the conditions are
weak, unpredictable or the lift is beyond an easy tow. So let's include
some of this potential as another "avoided cost":

$450

three weekends flying from or near where you live (Seattle in this
case), avoiding travel to Ephrata ($60), motel ($40/night), and food
($50 for two days). Of course, you don't actually have to fly on a
weekend, if you can get afternoons off during the week.

Net cost: $1750 - $1800 - 420= $500 cheaper to fly a SLS!

The above analysis ignores repair costs (routine maintenance is small)
on the engine, which are difficult to quantify because they don't occur
predictably and vary considerably with the age and type of the motor.
Factoring in these costs might show a SLS is more expensive to fly. Even
so, for an active pilot, the additional cost of the SLS may be easily
outweighed by the advantages, providing the pilot can afford the extra
purchase price due to the motor. If not, or if the pilot is not so
active, a partnership can make the costs attractive, while the
versatility of the SLS ensures that both pilots get most, perhaps all,
the flying they wish. As in any glider partnership, each partner is now
responsible for only half the costs.

My point is that the SLS is not as expensive as it seems, if a good
accounting of the avoided costs and the effect of its versatility is
fully considered. A similar analysis can be made for sustainer type
(e.g., Ventus BT) and "touring" style (e.g., Grob 109, Ximango)
motorgliders. For example, someone that flies airplanes and gliders
might discover the touring motorglider does both well enough that only
one aircraft is required.

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

Net cost: $1750 - $1800 - 420= $500 cheaper to fly a SLS!

I was thinking that you can prove anything with statistics,
but justifying a sailplane would be a serious challenge.
This guy is good !

Seriously, I doubt anyone is going to purchase an
Antares to "save money". More likely because:
- its an unbelievably good sailplane, raising the bar in
comfort, handling, and performance,
- the propulsion system is more powerful and reliable
than other alternatives, especially at high density
altitudes, and
- only one lever to operate the propulsion system

Obviously I'm biased !
Best Regards, Dave

wrote:
Net cost: $1750 - $1800 - 420= $500 cheaper to fly a SLS!


I was thinking that you can prove anything with statistics, but
justifying a sailplane would be a serious challenge.

Seriously, I doubt anyone is going to purchase an Antares to "save
money". More likely because: - its an unbelievably good sailplane,
raising the bar in comfort, handling, and performance,

And this why I think it's worthwhile to consider only the cost of the
motor when looking at costs of an SLSversus an upowered glider. Some
people think an SLS is expensive because they look at the total of a
sailplane with the motor, not realizing most of that money is buying a
high performance glider, fancy instruments, and a great trailer.

- the propulsion system is more powerful and reliable than other
alternatives, especially at high density altitudes, and - only one
lever to operate the propulsion system

I expect the electric gliders to have more predictable costs than the
gasoline powered alternatives, because electric motors tend to be much
more reliable. Exactly how long the batteries will last before they need
replacing isn't known, but it's still more predictable than when you'll
have a problem with your gasoline engine. And without a doubt, you will
be able to replace the battery with a cheaper, lighter, and more
powerful battery 5 or 10 years. That doesn't happen with the gasoline
motors!

This guy is good!

Wait till you hear me tell you how explain to your spouse why her
financial well-being depends on you getting an expensive glider!

--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

I recently had a year off from gliding and have come back to my gliding club
(www.ddsc.org.au) in Australia, to find the whole club fleet and most
private owners Flarm equipped. I believe we are the first fully equipped
club in Australia.

While getting checked out again over the last weeks in the club's two
seaters, I have to say the Flarm is amazingly good.

It is simply, predictable and will be going into our Nimbus soon.

Robert

"Marc Ramsey" wrote in message
om...
Bert Willing wrote:
"Marc Ramsey" wrote in message
. com...
I also suspect that FLARM won't do much to help where I'm most concerned
about a collision with another glider, the ridge running down the White
and Inyo mountains near the CA/NV border. FLARM advertises an effective
range of 2-3 km, or 1 to 1.5 nm. Given a head-on approach between two
gliders, each running at a TAS of 150 knots, you'll be lucky to get 10
seconds of warning. Might work for an ex-fighter pilot, but that's not
much time for someone like me...
You're wrong there, Marc. I'm not an ex-fighter pilot, and I had this
warning from my Flarm on the ridge. I took an evasive action and we
didn't collide. 10 sec is a lot when something is yelling at you.

Real world experience definitely trumps my speculation.

By the way, if anyone here in the US is interested, for another project
I've found multiple sources of FCC approved (no conformance testing
required, if used with specific antennas) 900 MHz RF modules with as much
as 20 mile line of sight range using 1/2 wave whip antennas. There might
be a way to do this without a huge up-front hardware and certification
costs. Software and testing would still be a big effort...

Marc

To add to what Robert wrote:

It is actually the OzFlearm - a unit manufactured in Australia based and
fully compatible with the original Flarm. Details at
http://www.rf-developments.com/page008.html

The money for club gliders and 2 tugs were raised by asking members for
donations.

Paul

robert wrote:
I recently had a year off from gliding and have come back to my gliding club
(www.ddsc.org.au) in Australia, to find the whole club fleet and most
private owners Flarm equipped. I believe we are the first fully equipped
club in Australia.

While getting checked out again over the last weeks in the club's two
seaters, I have to say the Flarm is amazingly good.

It is simply, predictable and will be going into our Nimbus soon.

Robert

"Marc Ramsey" wrote in message
om...

Well, maybe this is the answer for the US market? A quick scan of their web
site didn't reveal and restrictions to use in the US. So a question to all
glider instruments dealers in the US, what will it take to start selling
this unit in the U.S.?
I think if it will be IGC approved, we have a winner, and soon other flight
recorders will follow by offering flarm functionality...

Ramy

"PB" wrote in message
...
To add to what Robert wrote:

It is actually the OzFlearm - a unit manufactured in Australia based and
fully compatible with the original Flarm. Details at
http://www.rf-developments.com/page008.html

The money for club gliders and 2 tugs were raised by asking members for
donations.

Paul

robert wrote:
I recently had a year off from gliding and have come back to my gliding
club (www.ddsc.org.au) in Australia, to find the whole club fleet and
most private owners Flarm equipped. I believe we are the first fully
equipped club in Australia.

While getting checked out again over the last weeks in the club's two
seaters, I have to say the Flarm is amazingly good.

It is simply, predictable and will be going into our Nimbus soon.

Robert

"Marc Ramsey" wrote in message
om...