Soaring for fun?
 

Anybody soar or thermal a 12? Can it be done reasonably? Safely?

I haven't ever shut down in flight to go thermal hunting, but I have pulled power back far enough that I can't maintain level flight any longer and had plenty of fun "soaring" in the 12 that way. If the lift is weak you can bump the power up and increase your handicap, so to speak.

Is it cheating? I suppose. But it's still fun.

It works just fine in a -9. During the summer I quite often amuse myself by thermaling up at almost 1000 ft/min (or more) with the power at idle.

Google the P-38 Lightning that went wave soaring way back in time. Went out for a test sortie and was way overdue. He hooked the wave near Minden.

I used to catch the wave when flying skydivers in our 206. When it was active I would do 1,000fpm and blow there minds when I said - running in after 12 mins instead of 20 mins !

I frequently did it in a C-150.

I would think the -12 is similar or better.

if you want to experience soaring in your rv 12 go up to the highest altitude you want on the upwind side of your fav airport and shut down the engine. trim for best glide and start circling. watch the vsi for changes. if you have high puffy clouds try to get under them. best time is a couple days after cold front passage. look for circling birds. enjoy the silence of flight. if your sink rate is 600fpm and you can find a thermal stronger than that you will go up. :eek:

A few things about shutting down your engine and gliding. First, be over or near an airport (the accident report would be embarrassing). Watch your battery discharge rate and voltage. If the prop is stopped on the Rotax, I doubt you could get a windmilling start if the starter fails. If you turn off the battery to conserve voltage and lose ADSB/transponder...you may be in violation of FAA requirements. Seems to me that the "risk vs reward" of shutting down the engine isn't worth it just to ride a few thermals. That being said, I've shut my engine down in my RV-7 to do glide testing many times under very controlled conditions (with and without the prop stopped), but you need to be smart about your test procedures.

Can you soar/glide in an RV-12? Absolutely. It is almost a glider as it is...
Remember that once you find some good lift, slow to your "minimum sink"speed which will be slightly less than your best glide speed, then listen to some inspirational music such as "Jonathan Livingston Seagull" :)

Often
 

I often do this in the 172 spam cans. but i do not shutoff the motor, rather just pull the power back to conserve fuel and allow more relaxed thermaling. With the (older) 172's, any help in climb is good.

I dont do it with passengers thou, and i warn flight following, and never in high traffic areas.

for those that say leaving the engine on is "cheating", i would disagree. if you were in a real glider, you wouldn't have that spinny thing at the front of the airplane to provide lots of drag.. so to compensate for that drag, leaving it at idle seems like a fair compromise.

there's probably some math that can be done by someone smarter than me to find out how much drag the stopped prop would provide.. and figure out how fast it would need to spin to be 'neutral' at whatever min sink speed is. -- not provide thrust nor drag.

That said, I've seen a few videos of the Sonex Xenos motorglider (the 912ULS is an engine option amongst others) where the engine is shut down once at altitude/self-launched. There's only 1 Xenos accident report listed with NTSB, not related to the engine; however, off-field landings by gliders are usually non-reportable events anyway.

An interesting mod for the -12 may be swap-able glider size wings and tail. Even an OK glider like the Blanik L-23 has an empty weight of around 700lb.. not too far off from a rv-12.

Propless you say? https://cafe.foundation/v2/pdf_cafe_reports/PropCA.pdf

Just a small correction. When soaring and trying to climb in thermals, you should fly at your min sink airspeed, not best glide (L/D max). Min sink speed is slightly slower than best glide. There's a good article in this month's EAA Sport Aviation on how to calculate these speeds.

Minimum sink is, just like it sounds, the speed at which the aircraft is losing the least altitude in a given amount of time. In other words, this is the speed that will keep you in the air for the maximum amount of time. It is a good speed to fly in lift for maximum altitude gain.

Best glide speed is the speed at which the aircraft will cover the most distance from a given altitude. This is generally a slightly higher speed than minimum sink. Flying at best glide speed, your flight time would be shorter, but you would go farther across the ground. If you have an engine failure, you want to descend at your best glide speed.

One clarification: While circling in a thermal, the Minimum Sink Speed will be the Minimum Sink Speed for the angle of bank that you are using to stay in the thermal. The Minimum Sink Speed for a particular bank angle will be higher than the level flight Minimum Sink Speed. For shallow bank angles there is not much difference, but you normally cannot 'core' a thermal at shallow bank angles.

Min sink speed plus
 

Besides min sink speed, I find it useful to put down 10 degrees of flaps to fly even slower. The slower speed allows for a tighter turn at a slower airspeed even thou if the min sink may be a little higher. Its all about maximizing the climb speed in the thermal.

Looks like fun, but remember one thing. If you are shutting off your engine to soar and have a problem that gives you ?press coverage? the NTSB report will not be kind!

It strikes me that during this entire conversation no one mentioned the word variometer.

Reminds me of that line from the Ironman movie:

"How did you solve the icing problem?"

"What icing problem?"

"You might want to look into it."

:)

I know there are portable variometers, might want to look into one if you are serious about soaring.

Variometer
 

I havent been in a power plane that doesnt have one. Power pilots call them rate of climb indicators?

Variometers are typically IVSI. Standard VSIs have a delay that makes them somewhat unsuitable for soaring.

Total Energy Compensated Variometers
 

Not to mention that variometers in most sailplanes include total energy compensation to eliminate 'stick thermals'. A stick thermal is a false indication of rising air (lift) caused by slowing down and climbing due to trading airspeed for altitude. Total energy compensated varios show what the air mass is actually doing by factoring out any climb or descent rates caused by slowing down or speeding up.

Knowing how fast the air mass is rising or sinking, by excluding the rate of climb or rate of descent caused by changes in airspeed, makes it much easier to locate and center thermals.