Can someone explain thermals???
 

Hey guys i'm looking for a plane and gliders/slope divers REALLY spark my interest.I see a ton of people talking about thermals and staying in the air.What exactly is a thermal?I'm kind of new to plane flying and don't know any terms or any of this stuff.:?

RE: Can someone explain thermals???
 

The basics...
http://en.wikipedia.org/wiki/Thermal

RE: Can someone explain thermals???
 

You might want to think of a thermal as a rising, spiraling mass of warm air... Thermals are bubbles of air that are heated by refraction, heat radiating off the ground. A thermal starts as a mass of cold air which then gets heated and breaks off, forming a bubble of warm rising air, because hot air tends to rise. You can take advantage of the rising air to stay aloft with a glider. So, to catch a thermal, you need to be able to "see" the invisible masses of hot air. You will learn to do this by observing what kind of land radiates more heat, for example a parking lot or highway will radiate far more heat than a lake or dense woods. To catch thermals you need a stable glider with a very efficient airfoil...
You launch the glider, usually by means of a motor or high start. A high start is a long piece of Bungee cord that acts as a slingshot with your glider as the load.
You circle around and if there are any thermals at all, you will see that sometimes one wing tip will rise and cause the plane to bank. What you have to do is turn hard towards the area where your wing tip rose: if the left wing tip rises you bank hard left. By circling around, you will soon find a spot where the plane rises more and more as you spiral. You should keep spiraling in that spot, smoothly, and the warm air will carry your plane upwards. You can then disengage the thermal and look for another one.
The best kind of glider to start with will be a glider with a large wing. the bigger the wing is, the better. The wing should have some Dihedral, which means it curves upwards at the tips. It will usually be a 2 or three channel plane, which means that you have only elevator and rudder control, or elevator, rudder and flaps/brakes. The rudder is like the rudder in a boat: it steers the plane. The elevator controls the elevation and descent, and the flaps are surfaces at the back of the wing that extend or lower themselves to provide more wing area and wing efficiently. Brakes are surfaces that partially destroy the wing's efficiency, lowering speed for easy landings.
You should buy a four to six channel radio to begin with. Your radio will come with servomotors, small devices that move the surfaces, a battery and a receiver, as well as some accesories. Futaba and Spektrum are very reliable brands of Radios, so you should want to go for the best you can afford.

Here I will give you a few links to good starter planes and radios:

http://www3.towerhobbies.com/cgi-bin...=LXEFJ4**&P=ML : The T4YF, the best starter radio. $119.99
http://www3.towerhobbies.com/cgi-bin...&I=LXSFY3&P=ML : The 6EX, a more advanced and flexible radio which uses 2.4 gigahertz technology to eliminate interference, available for $ 259.99

http://www3.towerhobbies.com/cgi-bin...?&I=LXJ597&P=0 : The spectra, a great glider with a motor for easy thermal catching, kit form

http://www3.towerhobbies.com/cgi-bin...?&I=LXFG09&P=0 : SIG riser, easiest plane to fly, very cheap, available in kit form

http://www3.towerhobbies.com/cgi-bin...?&I=LXELP0&P=0 : The Gentle Lady, I laerned to fly with one of these, available in ARF (Almost Ready To Fly)

http://www3.towerhobbies.com/cgi-bin...?&I=LXJYP9&P=0 : The Spirit 100, Great plane, available as an ARF

http://www3.towerhobbies.com/cgi-bin...?&I=LXLGM6&P=0 : The Fling 2M, very light and very efficient airfoil, great for thermals, available as an ARF and also available in a 50 inch version.

http://www3.towerhobbies.com/cgi-bin...1p?&I=LZ1491** : Finally, the Spectra electric assisted glider, available as an Ultimate Combo for 225 dollars. Includes everything you need, even rubber bands and alkaline batteries for the radio...



Well I hope that helps. Now I need to rest my poor fingers, Ive been typing too long...:D

RE: Can someone explain thermals???
 

yeah i know the plane terms like contrls.what about something like these?
http://www.wonderhobby.com/skyha3rareco.html
http://www.raidentech.com/rercracoplgl.html
http://www.raidentech.com/3rarecoaiwis1.html

RE: Can someone explain thermals???
 

Wait a second... Are you thinking thermals or slope soaring? Cause slope soaring is very different.

RE: Can someone explain thermals???
 

Get this:
http://radiocarbonart.com/Pages/asecthermalmain.html
After watching this you'll know more about thermals than 90% of sailplane pilots, it's the best info you can get.

RE: Can someone explain thermals???
 

um....slope soaring is off hills and stuff right?or am i tottaly confused?and can't i just used a slope diver for gliding?

RE: Can someone explain thermals???
 

Soarrich,

Very simply, a thermal is some-what like a dust-devil. In a dust-devil, air heated by the earth's surface rises. Warm air is lighter than cooler air and therefore rises. You can see the dust-devil because of rising and rotating silt, sand, paper, and other trash. Once in Hawaii, while on training manuvers with the army on the "Big Island", a very large and strong dusd-devil made its way through our compound. Its vertical force carried silt, sand, rocks, doors, windows, and other heavy objects hundreds of feet upward; it was much like a tornado in that it had rotating winds, but had no weather associated with it. Our models or full scale sailplanes use the rising warm air to "lift" them upward. The rising warm air cools at altitude and falls downward as "sink". As a pilot, to gain altitude, you must learn to seek out the "lift" and stay out of the "sink".

Welcome to our sport,

Ernie

RE: Can someone explain thermals???
 

In slope soaring the pilot needs a slope. Wind pushes against the slope and forms a vertical wind current off the lip of the slope. You use this current to stay aloft. The current will come at an angle and it is at that angle at which you will get the best lift. For slope soaring you need a slope or tall hill and winds of at least 6 mph. Slope soarers are often heavier than thermal birds and usually have ailerons. Thy are much faster and can do many more maneuvers than thermal models. You can hand launch off a slope or use a winch. Read my post Slopes in Peru (In Response to Evan-RCU) and you can see some slopes and sloper models.

RE: Can someone explain thermals???
 

Soarrich has been a Level IV for 20 years. ;)

RE: Can someone explain thermals???
 

thanks evryone.i don't have a plane though.I'm selling an rs4 and have like 4 or 5 people making offers so in about a week i'll buy onne.Can i get one for like $100,$130 maybe as a RTF?Or do i have to spend about $200?

RE: Can someone explain thermals???
 

RTFs are good but have the disadvantage that hey never come with especially good radios. Try looking in the Sailplanes-Almost Ready To Fly section in Towerhobbies.

RE: Can someone explain thermals???
 

ok.can i get a setup for around a $150?

RE: Can someone explain thermals???
 

Depends if you get a balsa built up plane or foam moulded.

RE: Can someone explain thermals???
 

ok.what would you recomend?I don't know which is better.

RE: Can someone explain thermals???
 

how about the Hobbico Ventura?

RE: Can someone explain thermals???
 

The ventura and ventura mini are great! I am sorry I did not suggest them but they are very good learner planes.

RE: Can someone explain thermals???
 

ok great!i've seen videos and reviews and it looks like i'm going with a ventura.What would be better for say sports feilds?Like a football ini ventura i'm guessing?

RE: Can someone explain thermals???
 

Try to find an area that has plenty of grass to land on or highway or parking lots close because asphalt is the most efficient thermal radiator. You fly over a parking lot on a hot day and youll be rising like a rockt.

RE: Can someone explain thermals???
 

Well, I finally did it. I spent $25. I just ordered "Secrets of Thermal Soaring" and as luck would have it I ordered before July 2nd and got 20% off.

I can't wait!:D

Maybe I shoulda' ordered super priority shipping! Same day air! YEA! [X(]

RE: Can someone explain thermals???
 

soarrich,

I'm sorry that I addressed my post to you. It was meant for sgtcat. Congrats on being a Level 4!

Ernie

RE: Can someone explain thermals???
 

Level 4?

RE: Can someone explain thermals???
 

?????????????????????????????????????????

RE: Can someone explain thermals???
 

Alex.schweig (previously Zagiz),

Yes, a Level 4 or a Level IV...! See Rich's (soarrich) post.

Ernie

RE: Can someone explain thermals???
 

I still dont get what is a (LEVEL 4 OR LEVEL IV)