It's not the same with other self-launchers, of course, but my S10-VT
has a turbocharged, 4-cylinder engine rated at 115 (nominal)
horsepower.Â* With the turbo, it achieves its rated power to a very high
altitude, which I haven't seen stated, but it has a published service
ceiling of 33,000' MSL.Â* Density altitude has no effect on it other than
some reduction in propeller efficiency and engine temperature limits.Â* I
imagine the higher true airspeed for a given IAS at takeoff at high
altitude airports makes up for reductions in wing lift.Â* At maximum
power it burns around 5 gallons/hour (about 3.2 gph in cruise at 18,000'
MSL for repositioning flights), so I'd guess I burn less than a half
gallon of gas per normal soaring flight, including taxi and takeoff.

Engine overhaul will cost a few pennies more than with the smaller ships...

On 8/23/2019 10:30 AM, son_of_flubber wrote:
On Thursday, August 22, 2019 at 11:50:40 AM UTC-4, 2G wrote:

I only consume 1/2 gallon to launch my ASH31Mi motorglider to 3kft (the same was true for the 26e and DG400, and most every other self-launcher that I can think of, well maybe not the Space Shuttle). So, for a 4 hour flight my "burn rate" is 1 pint per hour.
Self-launch gliders are obviously appealing, but I'm curious about their limitations wrt density altitude and turbulence.

What is your climb rate in your typical density altitude?

Do you ever launch in turbulent conditions with lots of sink?

What density altitude leads you to cancel your flight?

What is the highest density altitude that you have launched in?


--
Dan, 5J