Stupid Question: How do you get down from a spec high in a thermal?

[AstroDad]

There have been very good thermals lately and I have been a bit zealous about riding them up high until I realize I am too high to see what I am doing.

A week or two ago I was trying to come down from a strong thermal with my Easy Glider Pro and it as I was pointing it steeply down towards me it went into some kind of overspeed flutter and ripped the wings off!

Then just today I was extremely high in strong thermals with my 4-day old Radian, decided it was time to come down so I put the stick in the lower right corner to put it into a spin for a couple minutes until I thought it was low enough to see which way I was pointing it. Somebody had told me that going into a stalled spin is a good way to come down without putting much stress on the airframe? I exited the spin and pointed it towards me and only slightly downward because I did not want to repeat what happened with the Easy Glider, but all the sudden the tail snapped off! I have found the fuselage but I am still looking for the tail. It broke off at the horizontal stabilizer and is intact below the stabilizer. Also the canopy somehow came off and was not at the crash site where the fuselage was located.

So how do I get down from these heights without destroying more gliders?

[condor-60]

......The practice I use is to fly inverted. Once you are at a reasonable altitude correct your attitude and then you can safely land your plane. Flying inverted kills off quite a bit of lift in your wings and allows for a slower descent.

Condor-60

[bjr_93tz]

There are many schools of thought on this one.

(1) Fly to a different part of the sky, chances are where there's lift there's also sink around it. Although we've all experienced a whole sky full of lift when we dont need it.

(2) Buy a glider with airbrakes and/or spoilers this will allow you to lose a lot of height without gaining too much speed. The bonus is you can control your landing point much easier.

(3) Buy a full composite glider and just put it into a dive. I doubt there's a thermal alive that will suck up a moldie in a vertical dive, although hail stones seem to get held up there quite well from time to time.

(4) Some will suggest flying it upside down for a while will work. If I can see the glider well enough to fly upside down I won't be looking to lose height but most gliders with a cambered airfoil should loose height faster upside down without building up huge amounts of speed.

(5) Running a slightly forward Center of gravity and trimming for a slow glide should see you holding in heaps of down elevator to maintain a high speed. This can give you good feedback as to how fast you're going as well, as you know how much down elevator your holding in.

Cheers
Brett

[Hossfly72]

Fly back upwind of the thermal also. There will usually be an area of sink behind a thermal, kind of following it.

[atjurhs]

For a RES, I put my stick in the far left or right back corner pulling full elevator and full rudder, and hold it there. The plane will continually stall and spin downward. I have no idea what sort of forces this inparts, but I haven't hurt a plane yet doing it. For a moldie, dive baby dive. These forces are much higher I'm sure :D

[SmokinJoe101]

How about do not put yourself in that situation :cool:

If flying at limit of vision, limited skill, foam sailplane then something is going to happen and it's not good. :eek:

sj

[condor-60]

BJR I had a "Hobie Hawk" in the 1970's and I guess it was the ultimate moldie of that era as it was almost an indestructable glider. The Hobie was in such lift that I had full nose down on my controls and it was still going up. I would have loved to have been near it to see this flight configuration but all I could do is imagine what it looked like.
I did finally break free of it by flying up wind and letting the lift drift away out from around me.

Condor-60

[Joe Minton]

AstroDad:


All the advice to this point is good and I've used each.

When really high, high enough that you can't see the stab, there is considerable danger that you'll overspeed your plane on the way down. Even moldies can flutter themselves to pieces in a dive. Don't ever use down elevator, just don't.

Flying inverted works if you can see the model well enough. Flying straight upwind always works if there is time. If your Xmtr has a high/low rate option, use the high rate position to engage extreme elevator & rudder -- then you can spin down.

The most important thing though is -- patience.

Ed Slobod once told me that fliers often destroy their sailplanes because they (we) get impatient (scared?) about how high and how far away our planes might be. He said that we shouldn't worry about taking 10 minutes to get down from an altitude we just spent 20 getting up to.

Whenever I let one of my planes get too high and too far away and feel panic setting in, I think about what Ed told me. I then calm down, add four-clicks of down trim or pop the spoilers, point'er towards home and wait. The hard part is the wait part.

Themals,
Joe

[AndyTheLegend]

AstroDad:


All the advice to this point is good and I've used each.

When really high, high enough that you can't see the stab, there is considerable danger that you'll overspeed your plane on the way down. Even moldies can flutter themselves to pieces in a dive. Don't ever use down elevator, just don't.

Flying inverted works if you can see the model well enough. Flying straight upwind always works if there is time. If your Xmtr has a high/low rate option, use the high rate position to engage extreme elevator & rudder -- then you can spin down.

The most important thing though is -- patience.

Ed Slobod once told me that fliers often destroy their sailplanes because they (we) get impatient (scared?) about how high and how far away our planes might be. He said that we shouldn't worry about taking 10 minutes to get down from an altitude we just spent 20 getting up to.

Whenever I let one of my planes get too high and too far away and feel panic setting in, I think about what Ed told me. I then calm down, add four-clicks of down trim or pop the spoilers, point'er towards home and wait. The hard part is the wait part.

Themals,
Joe

Good advice, Joe.

Andy

[StevenatorLTFO]

I have had two flights so far this spring, with a moldie (Starlight 2000) that even with crow, it was a bear to get down. One was at the Misty Meadows contest a couple of weeks back, popped crow and started diving 4 minutes into a 10 minute task, and was scared to death for the next 3 minutes, as I kept loosing sight of the airplane. Strong stuff, and everywhere I went was the same!!! More then likely, a woodie would have flown away or blown up!!!

South Side Steve

[lincoln]

Probably your spin was a spiral dive or you wouldn't have got to that speed so fast. Unless of course you damaged it earlier. I'd suggest that if you want to spin, you do some practice spins first so you can see what you're doing. Also, think you might try an inverted spin. Just plain flying inverted can also work. In any case, though, don't let the nose get pointed down too far, especially if the airfoil is not completely flat bottomed. With completely flat bottomed airfoils such as the one on the Olympic 2, you can sometimes lose lots of altitude by a moderate dive. On faster gliders this can be very dangerous unless you have very fine judgement.

When escaping upwind, you may need a bit of down elevator to get some speed, but if you can't see what you're doing very well it's a tricky thing. Best to know about how much down trim provides a reasonably fast speed. Investigate beforehand.

Crow and nose down on a composite glider loses altitude in a big hurry. I've seen very few thermals more powerful than that. However, there was the day I almost lost a .40 powered glow trainer straight up!

If you have a Radian or something, paint half or more of the bottom of the wing, full chord width, a dark color. This will give you a bit more visual range. White or pale blue or, for me, even orange can be hard to see if it's far away against a blue sky or clouds.

The Radian is an impressive glider but an owner told me that he thought the tail was a bit flexible. There may be some easy ways to stiffen it up, though you want to think about this carefully first to make sure it doesn't make things worse somehow.

Another altitude loss trick that may work with an electric is to spin the prop very slowly with low throttle, just enough to unfold it. Then you can point the nose down quite a bit without overspeeding. This is something you'd also want to practice at moderate altitudes until you are comfortable with it.

[lincoln]

P.S. not a stupid question. Last year I let an Easy Glider get away from me downwind and up until I couldn't see it well enough to get back.

[nuevo]

...

[glidagida]

In one piece! ;)

Cheers
GG

[prodjx]

Do a half loop then put the stick all the way forward and right or left this should produce an inverted spin, I've done this 2m floater's without destroying them. Just neutralize the control's to recover.

[Steve Boone]

I've found a quick way to lose altitude is to look at your timer and then tell your friends, "No problem, just ten more minutes and my 1 hour flight is in the bag!". This usually works quite well for me. :D

[AstroDad]

Ed Slobod once told me that fliers often destroy their sailplanes because they (we) get impatient (scared?) about how high and how far away our planes might be. He said that we shouldn't worry about taking 10 minutes to get down from an altitude we just spent 20 getting up to.

Sounds like Ed knows exactly what I was thinking both times I crashed. I suddenly felt like I was way too high and that I needed down in a hurry, when I should not have been in a hurry.

[AstroDad]

If you have a Radian or something, paint half or more of the bottom of the wing, full chord width, a dark color. This will give you a bit more visual range. White or pale blue or, for me, even orange can be hard to see if it's far away against a blue sky or clouds.

The entire bottom of my wing and horizontal stabilizer is painted black. The vertical stabilizer and top side of the main wing have reflective tape. I have found this livery greatly improves the visibility.

[blackoutjon]

ill tell you what, when you get that high pull out a chair have your little brother get you a coke and fly upwind and watch it come down nice and slowly

[prodjx]

If you can find some gold trim film put it on a vertical surface, if your circling it should flash every revolution.

[SaltyOne]

Quote:
"I've found a quick way to lose altitude is to look at your timer and then tell your friends, ......"

This works great for me too. Usually when I look at my timer and then look back up for my specked out plane it is nowhere to be found, or I'm looking at the wrong plane. I usually reacquire a visual on my plane when I hear a lot of yelling, screaming, and pointing and it is about 50' off the deck going straight down at 100 mph. Its happened more than once.

The moral of the story at least for me is: "Don't take your eyes off your plane when it is specked out."

George

[roydor]

I usually roll inverted and put full crow on, the plane literally falls out of the sky, the sink rate is about 3 to 4 meters per second and the forward speed remains slow so no risk of flutter. If I want to go down fasted I let the nose drop and the plane picks up speed and settles at about twice the normal speed, the sink rate is about 10 meters per second. To stop the descent just roll back and keep on flying.

[ronrange]

Actually you dont. You get down from a duck or goose. COULD NOT RESIST.

[Brendan Miller]

With my full house I fly away from the thermal and in speed mode and point the nose down but not to far down I just want to gain speed. I only do a toward spin if I am way to high and very uncomfortable, I just push the nose all the way down and to one side.

[RBMartin]

Flying out of the thermal is always good advice. I have been so high that just pointing the nose down in speed mode would be dangerous becuase I cant tell how fast it is going. I like others like to pull full flaps and just dive down. Doing this you are putting alot of stress on the flaps and they will wear out sooner. I also like to spin with full flaps, depending on how strong the thermal is will determine how effective this is. I have done this in a strong thermal and the airplane climbed. I recently have been playing with flying invertive to releave the stress on the flaps.

You also need to becarefull getting high, far away down wind on the back side of a thermal. Years ago I lost a plane becuase I was so far away every time I turned home the thermal pushed me off and it was so small I did not have time to correct. So I ended up getting farther and farther away I lost it.

What I really need is a better pair of eyes ; )

Bruce M

[panzerd18]

It seems like the Radian is not strong enough to spin if the guy had the tail break off??

I think flying inverted is the only option?

[RBMartin]

I have spun a Radian pretty sig and not had an issue. I do use alot of elev to keep the spin flat and not dev to much speed.With the motor you can also power out of thermal to a different part of the sky. With the engine weight if you can get out of the main part of the thermal it is not to difficult to get down.

Bruce M

[gary1201]

I have a radian. When it gets tool high for my comfort zone and time to come down, do not spin it down! I point the nose down at about a 30 degree angle for about 3 or 4 seconds,then level off. Fly level for 6 or 7 seconds until the speed has burnt off. Repeat stepping your plane down in this manner. Any direction changes should be made while flying level.
Gary

[gary1201]

I foregot to say I do this proceedure to get down with the motor off. You may have to point the nose down a little steeper if it is a real strong thermal.

[Hossfly72]

A motor gives you another option. Pull the throttle ALL the way off and raise the nose to bleed speed until the blades stop. Then give UP motor trim just until the blades tick over. I used this tactic with my old Electra and it works like a charm. It's almost like having spoilers. The prop creates no thrust but will create enough drag to help your sink rate. I fly 2 channel gliders now and I've successfully spun out of thermals a few times, but my blood pressure and heart beat went up faster than the glider came down. The easiest thing to do (and what Dave Thornberg says) is to fly upwind of the thermal. You will almost assuredly run into the sinking column of air behind it and it's MUCH safer than spinning down.

Now for real fun, try popping the flaps and gear in a full scale 172RG and spiralling down. Airspeed of about 70-75kts, nose pointed at the ground and over a 2800 ft/min drop! It'll make your belly button whistle the first time!

[Gavin Trussell]

Turn off your transmitter and sit down for a sandwich, She will come down. LOL

[Libelle201B]

A similar thread came up not long ago....anyways I would NOT recommend inverted flight unless you are comfortable doing it and you KNOW you have enough DOWN elevator to maintain inverted flight. If you don't you will find yourself in an inverted dive and panic will set in. You will pull back on the stick and goodby wings ! Unfortunately the Radian does not have flaps but they (flaps) are really the best way to get down in a hurry. My FS HP-11 was a flap only ship and it was really neat to be able to point the nose at the ground and not go much beyond 60-65 kts. A real life saver if you ever got into trouble. :)

[got lift?]

I usually just turn back towards home and use a little down elevator and the accumulated altitude to get me back home. I don't like scrubbing off altitude so I do it slowly... ; )

[solo6796]

I have seen a lot of responses here and elsewhere regarding flying inverted to lose altitude. I can fly my sailplanes inverted, but it seems to take quite a lot of pilot input to keep it that way. Especially a RES sailplane with so much dihedral, which makes the plane want to self right on it own. If it is so far up that I'm losing sight of it, flying inverted will be even more difficult without being able to determine accurate orientation.

I think trying this would lead to overspeed, or sudden stresses on the wings when trying to correct, or over correct, and probably a blown wing.

I think the safest way to lose altitude on a RES model is to try to get away from the thermal, and spin it down to a more observable height by putting the stick in the lower right or left corner. On my full house sailplane, again fly away from the lift, and hit full flaps. Point the nose down and no worries.

Once down to my "comfort zone", I either play around with some loops, rolls, inverted flying, other aerobatics, land normally, or start another search for another ride up...

AJ

[schrederman]

The best way is to have it be strong enough to just point the nose down... as far down as you want.

[akmoose43]

I see a lot of posts suggesting spinning the plane down. This works IF you know how to do a true spin. Otherwise you end up in a spiral dive, which is commonly terminal. Very high G forces.

Remember, the original post was for an Easy Glider and Radian. No flaps. The ailerons can be set up as spoilers, which is a good idea. Neither plane is designed for super high stress.

If possible, the best plan is to not fly too high, and fly out of the lift when you start getting nervous.

................Moose................

[Naxos]

akmoose43:

This works IF you know how to do a true spin

So how do you do a true spin? Is it possible with just rudder and elevator?

[StevenatorLTFO]

So how do you do a true spin? Is it possible with just rudder and elevator?


That depends on the airframe, and set up. Anything that is very nose heavy, will be less apt to spin.

[gyrokiteguy]

I watched a pilot try to get his EG down from strong lift yesterday. He put it into a spin and the tail broke off. I wrote about it here:
http://www.rcgroups.com/forums/showthread.php?t=556040&page=233

I learned 2 things from this. 1) I'll be putting a piece of carbon fiber in the tail of my EG. 2) I'll be adding spoilers.

[AndyTheLegend]

http://www.rcgroups.com/forums/showthread.php?t=990056

Andy

[PiK20b]

I spin my Paragon down. Spin entry is very easy and it has never changed into a sprial dive. Spins don't put much stress on the airframe. Gliders have the CG at the rear of the range when trimed out properly and that makes spins easy.

[2motheus]

Lincoln already said this.

Knowing what works with a particular plane ahead of time will give you a higher chance of success as well as a lower stress level.

In my case I've been pleased with going inverted with polyhedral RE planes. Yes - you need to know that you have enough down elevator to tuck under before you over-speed. Someone mentioned you may not be able to steer a polyhedral plane very well inverted. It's really not so bad with, again, some practice.

Tim

[Naxos]

Today I took the plane out and tried to go inverted, to practice the techniques mentioned here. :)

I went up to at least 1000 feet, and tried several times to roll it over -- no luck, it just went into a dive.

Then I thought I'd try tucking it under with the elevator. It went down OK, but then I couldn't get it to tuck under and go inverted. Then I couldn't pull up. Next thing you know I'd drilled it in from 1000 ft, smashed it to bits and destroyed the motor. :eek: :(

Fortunately it's not too bad... I should be able to put it together again...

Turns out that high wing polyhedral planes don't like to fly upside down...

:rolleyes:

[Libelle201B]

Today I took the plane out and tried to go inverted, to practice the techniques mentioned here. :)

I went up to at least 1000 feet, and tried several times to roll it over -- no luck, it just went into a dive.

Then I thought I'd try tucking it under with the elevator. It went down OK, but then I couldn't get it to tuck under and go inverted. then I couldn't pull up. Next think you know I'd drilled it in from 1000 ft, smashed it to bits and destroyed the motor. :eek: :(

Fortunately it's not too bad... I should be able to put it together again...

Turns out that high wing polyhedral planes don't like to fly upside down...

:rolleyes: Unfortunately these are the kind of results you get if you don't have a fair amount of experience with roll's and inverted flying. From the sounds of it you probably didn't have near enough airspeed to "roll" it over on it's back. Although your plane is not a sailplane the principals are the same. A roll with any sailplane requires a shallow dive to gain airspeed (energy). With a RE sailplane you would start with airspeed and then a gentle pull up (climb) with that airspeed to get the nose pointing up a small bit and then FULL rudder, with DOWN elevator at about the time you reach the 90 degree bank point, all the while holding in FULL rudder. If you want to stop the roll at "inverted" you slack off on rudder as you go past 90 degrees until NO rudder as you reach the inverted position. You will have to maintain DOWN elevator all through this phase of the roll. Once inverted you will have to use the rudder to maintain wings level inverted flight and DOWN elevator. Inverted flight because of the now anhedral wing will be much trickier requiring constant input. Maintaining enough airspeed while inverted is important if you want to "roll" out of it. It will no doubt require most if not all of your down elevator to stay inverted. If full down elevator after a moment or two starts a gentle inverted climb thats great, just reduce the DOWN a bit and you will regain airspeed. If you find that full down is not maintaining AT LEAST level inverted flight, or worse, a shallow dive that keeps building airspeed, you must ROLL back to upright flight ie FULL rudder again until you are upright. Trying to pull back on the stick (UP) elevator, a common mistake for beginners, while building up airspeed inverted is a disaster waiting to happen. If this is the case you will need MORE down elevator.
Unless you know your plane, NEVER "tuck" into inverted flight ie full down elevator from level flight in order to go inverted. (1/2 outside loop). The EASIEST way to learn inverted flight is to simply start a loop with some airspeed and hold in DOWN elevator as you reach the top of the loop and follow the above instructions. Rolls and inverted flight take lots of practice and above all, practice at altitude :) P.S. My rule of thumb is to ALWAYS have enough airspeed while inverted to ROLL out of the maneuver.

[Naxos]

Thanks for the tips, I've printed that out to take with me the next
time I fly.

Unfortunately these are the kind of results you get if you don't have a fair amount of experience with roll's and inverted flying.

Well, gotta get that experience somehow... :)

I think you're right about not having enough airspeed to complete the roll. Once I get it put back together I'll try again. I don't know why it didn't occur to me to try an inside loop (which I know I can do) instead of an outside loop.

The thing I still don't understand is why my elevator became completely ineffective once I started plummeting straight down (not spinning, nose pointed at the ground). Neither up nor down elevator had any effect.

I checked the plane after the crash and the control surfaces were working perfectly, so it wasn't an in flight failure. I also had high rates set on
the transmitter, for maximum elevator throw (as recommended in the manual)

Do you have any thoughts on what I could have done to recover?

By the way I am getting back into sailplanes after many years of not flying. I'm building an unpowered Vista right now. So that's why I'm hanging around the sailplane forums, in case you were wondering...

[AstroDad]

The thing I still don't understand is why my elevator became completely ineffective once I started plummeting straight down (not spinning, nose pointed at the ground). Neither up nor down elevator had any effect.


I have experianced something like that.

My wings were fluttering and I figured my elevator was ineffective either due to turblance from the wings fluttering, or the forces of the wings fluttering was overpowering the elevator.

My original question was regarding how to save your plane when it is so high it is very difficult to keep sight of it and its orientation. Aerobatic manovers like inverted flying are out of the question when you are doing all you can just to not loose sight of your plane. If I can see my plane well enough to attempt to fly inverted then I am not really in trouble of loosing my model.

Some of the advice I have found to be practical is not to feel the need to rush down. Somebody said something about if it takes 30-min to get up there then I should not feel the need to get down in 2-minutes. Also thermals are not going to cover 100% of the sky, so when I am up high I have been moving to another part of the sky expecting that thermals cannot be everywhere. So far so good!

[Libelle201B]

The thing I still don't understand is why my elevator became completely ineffective once I started plummeting straight down (not spinning, nose pointed at the ground). Neither up nor down elevator had any effect.

I checked the plane after the crash and the control surfaces were working perfectly, so it wasn't an in flight failure. I also had high rates set on
the transmitter, for maximum elevator throw (as recommended in the manual)

Do you have any thoughts on what I could have done to recover?

. Naxos, that is really weird. I can only think that the elevator was blanked-out by the wing or possibly at a much higher speed the servo didnt have the power to move the control surface enough. In either case the plane should have gone into a loop after releasing the elevator stick. If you had no elevator control I don't know if there is anything you could have done :(

[2motheus]

Naxos,
Sorry to see what happened to your plane. My recommendation to "make sure you have enough down elevator to tuck under" assumed you have enough up elevator to recover quickly if the tuck doesn't work. Libelle's description of transitioning to inverted from an inside loop is a better approach, but you need to have good visual contact to control that one.
To remedy the lack of control with your yellow electric, you might try moving the CG back for a more effective elevator, and also checking that the elevator pushrod doesn't buckle under compression forces. I.e. if the elevator control rod is pushing to go "up," it may be bending instead of moving the elevator.

AstroDad,
Yes - when you're at the edge of visibility it will be hard to control inverted flight well. However, once you know what works with a particular plane, you can do the maneuvers without perfect steering. Your plane will still be upside down most of the time without gaining too much airspeed. The airfoil will be working with gravity to lose altitude. Of course, if you're downwind, having inconsistent steering will not bring you any closer to home.

Tim

[RBMartin]

Something else you can check is does the elev move under load. If you were trying to pull up from a dive that would put sig load on the elev. If there is slop in the linkage,bendable rod, or the like that could prevent the evev from moving even if it will move normally on the ground. just noticed 2moth said the samething, sorry for being redundant.

Bruce

[Naxos]

AstroDad, sorry to get off topic there... I really liked the suggestion I saw to set a mix so that when you flip a switch the elevator becomes trimmed for a safe shallow dive. Of course you'd need to set that up in advance, and it wouldn't get you down quickly.

2Mothius and RBMartin both mentioned the possibility of push rod deflection under load. Examining the wreckage I can see that's probably exactly what happened -- My push rod "pushes" for up elevator and does seem to bend pretty easily when under load. Come to think of it, the plane turns left easier than it turns right (motor off) and I think the same thing is happening with the
rudder!

By the way, despite the sarcasm in my first post, I only blame myself for the mishap.

[2motheus]

Naxos,

We're better off when we learn from mishaps - our own and those of others. Now we want to hear confirmation that you've got that bird in the air again.

Welcome back to sailplanes...
Yesterday I was doing a demo flight with an electric trainer (Easy Star) for a 12-yr-old kid and his dad. Alas, the batteries were about dead, so we were just sitting in the grass enjoying the day. I noticed some changes in the wind, so used the little remaining battery to get to the lift. In short order the plane was several hundred feet up and many mistakes high, so we were able to get in some good "dead stick" training time.

Tim