2G wrote on 4/13/2020 9:19 PM:
On Monday, April 13, 2020 at 7:48:51 PM UTC-7, Eric Greenwell wrote:
2G wrote on 4/13/2020 5:54 PM:
Electric gliders won't cut it when you have to motor a was to the lift, like at Williams. Once, Jim Leedy and I motored from KRLD to Mt. Rainier in his Taifun to get to the wave lift.
The Williams case is one I considered before choosing the Jeta. On the map, it
looks like about 20 NM the to hills to the west. Most electric gliders have that
much range; eg, the Gp15 Jeta with the large battery could launch, motor the 20
miles, and still have about 55-60 NM range left. The small battery would only have
30-35 nn range left, though. The AS34 would have about 45 NM range left after
motoring from Williams to the hills; the miniLak FES also about 45 NM, maybe more.
Everyone knows the gasoline powered self-launchers all have powered ranges that
exceed the best electric range, but that is irrelevant for most of the people
buying an electric glider. They want to eliminate the tow and dramatically
increase their chances of getting home, and the electric glider gives them what
they want. If you dream of flights that require hours of power, or airfields that
don't have electricity, you must stay with gasoline.
--
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
The launch has to be 4kft, min and the distance is more like 22nm. And what if the lift is further into the hills? And what if you have a headwind? And if you don't connect you don't have a glide back to Williams. The same thing goes for Minden. The margins are either non-existent or too thin for my tastes. Of course, you could always get a tow. In fact, save the cost of a FES and fly a pure glider.
There are several ways to deal with your worst case scenario:
1) don't fly on a difficult day
2) take a 5 mile, 4000' tow, leaving plenty of reserve to return to Williams
3) accept the possibility you might have to land at Antelope Valley
4) own a GP15: motor the 25 NM to 4000', and have 45-50 NM range left.
For 4), there no worries about getting back to Williams with that 10 knot tail
wind, 2500 agl height where you gave up trying to connect. The AS34 and miniLak
should be OK, too. Connecting with difficult lift will be easier in the electrics:
run at low power while searching around until you find something, turn it off, and
5 seconds later you are flying a glider again. Maybe not quite so easy in the
AS34, with it's more conventional pylon.
The fact is, most people do not fly where a lot of range is required, and most are
currently flying gliders with ZERO powered range (pure gliders). To these pilots,
the range of current electric gliders is very appealing. Think about it: if
maximum range was the crucial factor in selecting a motorglider, we'd all be
flying Stemme S10s! Right, Dan?
--
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