Getting Out of a Strong Thermal with an RE Plane

[AndyTheLegend]

Hey everyone,
Yesterday there was booming lift everywhere. A great day for the E-BoT. The hard part was getting down safely without spoilers. I was forced to just tighten my turns and feed in down elevator. I gained way more speed than I wanted. My question is how do you get out of good thermals with just an RE plane?

Andy

[ronrange]

You might want to fly inverted.

[greyhound flyer]

Flying inverted is one way. It's especially fun with poly ships staying ahead of their desire to right themselves back to fuselage on the bottom. Looping is another. Steep descending turns also work.

With full house ships, you can drop the flaps and point the nose down. As long as the flap servos have holding power to keep them down, you won't overspeed the airframe.

[schrederman]

Inverted is the best way. I've climbed while looping... :eek: ... Your BoT has a relatively flat-bottomed airfoil and they are very draggy while inverted and producing lift upside down... probably more effective than spoilers... though I don't suggest trying to spot land that way... :D ... Most folks think strong wings and tails are just for launching. I really enjoy diving straight down out of these things and screaming along like a moldie. With the carbon fiber spars and building techniques I use, it's no problem... Getting down from up high in a hurry is just as important in competition... and fun flying... as launching. In fact, if you're up high and just fun flying, ripping the wings off while trying to come down kinda takes the fun part out... :rolleyes:

Jack

[ezmo]

Never had such occasion to get into such powerful thermal. How about trying to dive steep to get speed and pont to downwind to get out lift....

[schrederman]

Something to think about... if you're already down wind, getting out of the thermal on it's down wind side will mean you have to come back through it to get home...

Jack

[JrcSeller]

How about a spin? Full up elevator along with either full right or full left rudder brings it down without airspeed. Just hold it until you reach the altitude you want. If there is a strong wind, watch to see that it doesn't blow away. Oh, some planes don't spin...like a Compulsion but RE ships should be fine.

[OVSS Boss]

Inverted is the way with out getting to a Vne situation. Spirals, which for an RES ship is the closet to a spin you can get will finally bring you to your Vne. Even with a a Grand Esprit and all the flexing going on there, it worked great.

Just what ever you do, diving in any form is not the answer.

Marc

[John Walter]

Just what ever you do, diving in any form is not the answer.

Marc

It's an answer, but a very bad one. ;)

[Libelle201B]

I wouldn't suggest flying inverted at all unless you are accomplished at doing it and it is also demonstrated that you have enough down elevator authority to maintain level inverted flight. The last thing you want is a high speed inverted dive of sorts with the untrained pilot panicing and pulling back (up elevator) on the stick, which would more than likely destroy the sailplane. :(

[AndyTheLegend]

I wouldn't suggest flying inverted at all unless you are accomplished at doing it and it is also demonstrated that you have enough down elevator authority to maintain level inverted flight. The last thing you want is a high speed inverted dive of sorts with the untrained pilot panicing and pulling back (up elevator) on the stick, which would more than likely destroy the sailplane. :(

I kinda agree. I doubt I would have enough elevator or orientation for that matter. I'm sure it would work if done right, but I'd be a little worried. I'm going to try going downwind and doing a spin downwards. We'll see how it goes. Thanks for all the suggestions.

Andy

[Batmanwpg]

I put the stick into a bottom corner. i.e. full up elevator and full rudder in either direction. Do it on high rates though as the more throw you have on those control surfaces the more drag will be produced. Works even better if you have spoilers also deployed.

[Libelle201B]

Hey everyone,
Yesterday there was booming lift everywhere. A great day for the E-BoT. The hard part was getting down safely without spoilers. I was forced to just tighten my turns and feed in down elevator. I gained way more speed than I wanted. My question is how do you get out of good thermals with just an RE plane?

Andy Andy, the best thing you can do with a RE only sailplane is to be very careful to avoid such a situation. If you are in a really good thermal and your plane is getting smaller by the second it is time to scoot out of there or employ some of the methods already discribed. You might want to set up your elevator trim to give you a fast glide (not a dive) but a safe fast glide with full down trim. Thats what I meant by "scooting" out of there. You would want to head away from the lift either up wind or to the sides. Going down wind might get you really far away and you might not make it back to the field or even worse, loose sight of your plane. Given a modest 4 knot thermal, and a typical rc sailplane minsink rate of about 2fps, you will be climbing at about 280' per minute, or 4.66' per second. In a short 7 minutes you would be at 2000'. Things happen fast in good lift, be prepared :)

[Soar_dude]

Run you motor so it its turning the prop enough to deploy say less then 1/8 throttle this will create drag and slow down the plane in a dive. What works best for me is to put it into a spin with full up elevator and full rudder.

Soar Dude

[daja]

This is for my R/E sailplanes (which is all I have) :o
Some other flyer helped me set up my radio to have a down elevator switch. I use it for various reasons, one is coming down out of the sky faster.
(big thermal or it’s getting late and I need to get to work) :rolleyes:
I have a Futaba 6EXAP, I think it’s a older model but is programmable.
This is what he showed me.

You go into the program mixer option and assign it on
I am using the “channel 5 landing gear switch” to mix the elevator with. When the switch is back the plane fly’s normally, Flip the switch forward for down and I have some mixed in down elevator. I use between 6% and 10% of down elevator. When I need to get moving down faster I flip the switch forward and I can see the plane pick up some speed but it is no where near diving. The plane flys faster but it basically flys with a new “hands off” neutral point. It is decending, but I am familiar with the speed I have set it with. Maybe this only works with light sailplanes with thick airfoils, but for me it’s great.

I find this easier then trying to determine exactly what is happening when I can barely see it. :eek:

daja

[glidermang]

Andy:

I used to do it the same as batmanwpg: full up-and-over controls. Loops are good, too. Also good is leaving the area of lift.

The last time I found myself in that situation, I had my Hobie Hawk up and it was getting smaller, fast. I bet it covered several miles in straight lines, eventually circumnavigating the field (North a while - hmmm, it's climbing again, let's try East for a while). But, I got it back alright.

Yours, Greg

[AMBeck]

Speaking of spinning out of lift, may years ago, I met the guy that held the under 100HP altitude record at the time (can't remember the exact class, but it was in a Luscombe). He did it in a Colorado wave. Said that the engine quit at about 16,000 feet. He went way higher than that. If I recall, it was over 30K feet. Well, he was getting tired and very cold up there, so decided to spin down. (Luscombes are good spinners!) 20 turns later he had lost all of 500 feet! Backing over to the down side of the wave did the trick, and he was on the ground an hour later. So, you can't always spin out. Leaving the area usually works for me. On some booming days I've made tours that probably qualify as cross countries.

[AndyTheLegend]

Speaking of spinning out of lift, may years ago, I met the guy that held the under 100HP altitude record at the time (can't remember the exact class, but it was in a Luscombe). He did it in a Colorado wave. Said that the engine quit at about 16,000 feet. He went way higher than that. If I recall, it was over 30K feet. Well, he was getting tired and very cold up there, so decided to spin down. (Luscombes are good spinners!) 20 turns later he had lost all of 500 feet! Backing over to the down side of the wave did the trick, and he was on the ground an hour later. So, you can't always spin out. Leaving the area usually works for me. On some booming days I've made tours that probably qualify as cross countries.

That would be one heck of a day. 30K with my BoT :p . That would be an amazing ride though in a real sailplane.

Well it is true that if there is a good thermal, theres also good sink on the downwind side. Here's what I'll try next. Fly downwind of the lift. Then using a switch, down elevator. Right or left rudder to put it into a good spin. Thanks everyone. I thought this would be an interesting topic.

Andy

[Joe Minton]

Spinning, spoilers, flying inverted (easier than it might seem) and flying straight out all work.

The problem with many of us, including myself, is impatience (panic) when the darned thing is reluctant to get down quickly. Ed Slobod once rhetorically asked me why people were so impatient about getting down in two minutes when they spent 20 getting up there. "What's wrong with taking 10 minutes?" he asked. Now if my plane gets too high and I start to get nervous, I think about what Ed said and just fly the thing.

Joe

[Riserflier]

Andy The Legend:

You've got power... use it to fly down and out.

If you had no power, as "real" sailplanes are designed and built, you probably would have learned your limits before getting sucked in to an unmanageable condition.

Flying without power challenges your skills and tests your experience. Power is a crutch that veils your weaknesses and minimizes your strengths.

Riserflier

[lincoln]

I'd say, go up on a normal day and practice to see how much down elevator you have. Do a half loop and then feed in some down elevator to see if you can make it fly fairly slowly that way. If not, roll out or finish the loop, but don't wait more than a couple of seconds if it starts to go fast. Then, in a boomer, the first choice is to fly someplace else, but if you can't find down air, an inverted spin is not bad.

The BOT, I hear, is not totally flat bottomed. If it was, with a relatively thick airfoil like on the Oly 2 or 650, a shallow dive would bring it down pretty quick without overspeeding. But that doesn't work if your airfoil is faster.

[WEB01]

I've had my BOT in that same situation.... I specked it out and then it winked out (couldn't see it at all). Did the flat spin as described (push the stick into the bottom left or right corner) and the BOT spun back down into sight beautifully. That also helped reduce the heart rate that spiked when I realized that this awesome thermal had just taken my prized airplane from me.

[aeajr]

When I was first learning to fly a thermal glider I had my Spirit RTF up in a thermal, 3 channel AM radio in hand. It was climbing like mad and I was so excited, I called my friend Ray.

Hey Ray, look at it climb. :cool:

Ray grabbed the radio out of my hand and put the stick in the lower left corner till I lost about 200 feet, then turned the plane toward home. :( When it was over the field he gave the radio back to me.

What was that all about? :confused:

Buddy, you were in a hit sucker. Another 10 seconds and you would have lost sight of the plane. And you were moving down wind so fast that you would have never made it back. :eek:

Sure I had been warned and sure people told me about these things, but I was so excited to have caught a thermal, I did not even think of these as possibilities.

I was just so excited to have caught a thermal I was not about to let it go. Apparently it was thinking the same thing about my Spirit. ;)

[Norm Furutani]

I wouldn't suggest flying inverted at all unless you are accomplished at doing it and it is also demonstrated that you have enough down elevator authority to maintain level inverted flight. The last thing you want is a high speed inverted dive of sorts with the untrained pilot panicing and pulling back (up elevator) on the stick, which would more than likely destroy the sailplane. :(

Keeping in mind what Libelle has said, flying inverted is probably the most effective way out of lift.

Before you get in that situation practice the procedure and see how your plane flies upside down. Half loop inverted and hold full down. If it starts to dive inverted, just finish the loop. Don't let the speed pick up or you can blow the wings off! If it holds inverted flight, work on the steering. The odd part about flying a R/E plane upside down is the rudder direction still works as if right side up. Don't get too low because the recovery is going to take some room. I suggest doing a rudder roll out of inverted, it's easier on the wings, rather than looping out. All this maneuvering is going to take full throws, so make sure you're on full rate.

Again, don't forget what Libelle said!

- Norm

[OVSS Boss]

Someone said that they are not sure they have enough down elevator. In my thoughts, on an RES ship (except maybe an Ava or full flying stab type), you need all the down elevator throw you can get. Down gets you out of more messes than all the up in the world.

And as was said, inverted recovery from altitude is not that hard.

Marc

[jetmaven]

Yesterday Was In Fact Boomer Day In Florida ,totally Out Of Control In Lakeland.

[Libelle201B]

Yesterday Was In Fact Boomer Day In Florida ,totally Out Of Control In Lakeland.jetmaven, where do you fly in Lakeland? I am in Lakeland about two times a month....I almost stayed yesterday to fly my Libelle. (Seminole Lake GP) I would like to meet with other r/c ers in the Lakeland area to start a r/c soaring club.

[jcstalls]

Ditto on the invert and against the directed wind with spoilers up, as this is what I learned flying a Thermic 72 streached to 3 meters flying out in Taft w/ Ross and Bob two decades past. The only way to her down in the same condition she went up with.

Jared

[condor-60]

.....I once had a Hobie Hawk in such a thermal that I had full nose down and it was still going up. I would have loved to have been closer to it just to see that configuration. I finally was able to head cross-country and set up a 747-approach
from way,way out yonder and landed it pretty much at my feet.That was a hell of a flight.

Condor-60

[ozmo01]

How about a spin? Full up elevator along with either full right or full left rudder brings it down without airspeed. Just hold it until you reach the altitude you want. If there is a strong wind, watch to see that it doesn't blow away. Oh, some planes don't spin...like a Compulsion but RE ships should be fine.

This is how I was tought to dethermal a stock Gentle Lady.
Some standard woodies won't tolerate the high speed options.
in some cases a floater in strong lift won't respond to down elevator so you roll it UP along with all the rudder it has. no structure stress.

[Hossfly72]

If the thermal is moving this way ----->
Then I fly this way <--------
There's sink behind the lift, that's why we drift with the thermals.
On a calm day, well, to quote the preacher from Blazing Saddles,
"You're on your own son."

[highflier]

One thing to note is start bailing out early. One of my first really good thermals, like many pilots, I decided to get the most out of it. I was saying to my wife which was on looking, It is getting pretty small I think I will try to bring it back a bit...... Then our next words were. It just disappeared!!!..

Well After about 10-15 seconds of spinning it came back to site, But even then I had a hard time with orientation. I opted to fast fly towards me. Which actually was hard to do as I could not tell which way the dot was facing. In the end I got it back and in the process released just how far downwind I had gotten.

This was in a RTF spectra that had the wing busted in half and repaired kinda iffy. Then converted to brushless and lipo's as it diet program to get some weight back out of it.

All it all. Without good site of the plane, and effects of Panic, Spinning is the no brainer action. Everything else requires thought and skill.

I am curious about how high I was. The plane actually went into the Dark thunder clouds.

Highflier

Same plane different day
http://www.youtube.com/watch?v=Ge6olqkGp50

[Ercoupe Ed]

Depending on the wind, blowing towards you or away from you, you can "stall-spin" the airplane.Works best if wind is blowing towards you.
A BOT should be able to have some down fed in and simply be patient and fly it down.
Set up either a "square" or "rectangular" approach pattern ( just like a full scale airplane) and fly each leg with as much down stick as you're comfortable with.Don't rush it, take your time and get down.
Start out flying one leg, then a gentle turn to 90 degrees of the first leg, then another gentle 90 degree turn, while keeping down elevator with your TX stick.
If you're flying in a contest and going for a spot landing, and really high, don't let anyone tell you "more down", just take your time and fly the airplane, better to go over on a timed flight and lose out on a spot landing, but you still have an airplane left!
If you spin it, just watch the airplane and if necessary feeed in a little opposite rudder to slow the spin down.
But in a really violently strong thermal, Ive seen sailplanes climb while in a spin or looping like Jack mentioned.

[AndyTheLegend]

Depending on the wind, blowing towards you or away from you, you can "stall-spin" the airplane.Works best if wind is blowing towards you.
A BOT should be able to have some down fed in and simply be patient and fly it down.
Set up either a "square" or "rectangular" approach pattern ( just like a full scale airplane) and fly each leg with as much down stick as you're comfortable with.Don't rush it, take your time and get down.
Start out flying one leg, then a gentle turn to 90 degrees of the first leg, then another gentle 90 degree turn, while keeping down elevator with your TX stick.
If you're flying in a contest and going for a spot landing, and really high, don't let anyone tell you "more down", just take your time and fly the airplane, better to go over on a timed flight and lose out on a spot landing, but you still have an airplane left!
If you spin it, just watch the airplane and if necessary feeed in a little opposite rudder to slow the spin down.
But in a really violently strong thermal, Ive seen sailplanes climb while in a spin or looping like Jack mentioned.

The stall spin doesn't seem to work on the BoT. It drops its nose pretty sharply and picks up some speed. I'm gonna give it all another try though, although winds are supposed to be 15mph here so proly a no go this weekend. I'm also going to try some spot landings too. Should be interesting with no spoilers.. :) Thanks all the suggestions everyone.

Andy

[schrederman]

You may have to give yourself more up travel for it to stall and stay stalled enough to spin.

Jack

[Texas Buzzard]

Prevention is better than having to resort to drastic measures. Too much of a good thing may be dangerous.

If there is any breeze at all remember the thermal moves with the wind
So exit the lift at 90 degrees with respect to the direction of the wind. Keep going in a straight line to exit until you find the down draft.

Our thermals here are usually small in diameter and get blown to heck as they ascend. I envy you fliers who do have those trash movers. :) :cool:

[scaflock]

Well strong thermals were not a problem here today. I thought I saw a vulture with his thumb out begging for some lift!!! :eek: ;)

Jeff

[Batmanwpg]

The stall spin doesn't seem to work on the BoT. It drops its nose pretty sharply and picks up some speed. I'm gonna give it all another try though, although winds are supposed to be 15mph here so proly a no go this weekend. I'm also going to try some spot landings too. Should be interesting with no spoilers.. :) Thanks all the suggestions everyone.

Andy


When you put the right stick into a bottom corner, i.e. full up and full rudder, are you releasing the stick when it starts to spin? If so that's not the way to do it. You have to hold the stick at that position for the full duration of the spin. This helps to control speed while spinning down. Use high rates for full deflection on the rudder and stab. Also, I only do this when the plane is fairly close so you can gauge the height you are coming out at. As others have said put in a couple of clicks of down trim in to bring the plane back first. Be patient, it will take time to get it back.

[Libelle201B]

The stall spin doesn't seem to work on the BoT. It drops its nose pretty sharply and picks up some speed. I'm gonna give it all another try though, although winds are supposed to be 15mph here so proly a no go this weekend. I'm also going to try some spot landings too. Should be interesting with no spoilers.. :) Thanks all the suggestions everyone.

Andy Andy, the plane WILL drop it's nose and pick up SOME but not much more speed. As mentioned hold the elevator full back and the rudder full left or right. After several 2-3 turns it should settle into the spin and the corkscrew turns should be uniform with no tendency to get larger or smaller and no additional speed building up. Do not expect to see a FLAT SPIN. If the turns start getting larger and the speed continues to build up, you are in a spiral dive!!! If that happens, get the wings level again (full opposite rudder) and very carefully apply up elevator to stop the dive.

[Desert flier]

Libelle what a great glider wanted to call my daughter Libbelle all was going well untill my wife found out it was a glider name I specked my bubble dancer out at 4000ft lost it and then caught a glint pulled brake and then spun back stick and full rudder here is the trace As can be seen by the trace the decent is fairly steep :)

The flat bit at the top was trying to fly out of lift into sink i have a eagle tree vario a great gadget takes me back to when I used to fly real gliders before I got married and had money :D

[Libelle201B]

Libelle what a great glider wanted to call my daughter Libbelle all was going well untill my wife found out it was a glider name I specked my bubble dancer out at 4000ft lost it and then caught a glint pulled brake and then spun back stick and full rudder here is the trace As can be seen by the trace the decent is fairly steep :)

The flat bit at the top was trying to fly out of lift into sink i have a eagle tree vario a great gadget takes me back to when I used to fly real gliders before I got married and had money :D I love my Libelle . WOW what a great flight with the bubble dancer, I'm glad you didn't loose it. It's amazing the equipment now available for rc soaring :)

[Fred_L]

We have a contest for 2m 2ch aircraft. Every so often you hook a boomer, but the flight is only supposed to be 6 minutes duration, so you need to come down.
I prefer to spin the aircraft. It's gentle on the airframe, the descent rate is managed and the constantly changing presentation makes it easy to keep sight of.
A spinable aircraft requires a good bit of up elevator and a rearward CG to maintain the stall on the inside wing.
I have tried outside loops (bunts) too and that really kills the height/energy.
Most guys just zoom down at high speed, however the most common aircraft used in the competition is not built up, but poplar sheeting over foam wings with a fibreglass fuselage.
Fred

[camdyson]

When it's at 2000' and climbing, good luck flying inverted... ;) At least spinning can be done unsighted, so it's still my pick.

Sometimes they still go up - from experience - and you just have to hope you put your phone number in it and set the failsafe. You'll get bigger bits that way - from experience... :D

As a paraglider pilot, I agree that avoiding "cloud suck" is the best option, so fly away early (crosswind).

Cam