I'm new to the sport of hand launch, so please be gentle with me..

I was thinking.. that if you pegged out a say 10m (30ft) square black plastic sheet in the corner of a field, in a wind shadow, ( i know such a field) on a sunny day, do you think it would produce any usable thermals for me and my little Elf to float about on..? or am i oversimplifying things as usual..

Chris..

I think you would be better off lighting a camp fire...

thanks jrbackus but the field in question is a school playing field so setting fire to it is not an option..unfortunately..

Just get all the guys at the field together in a group and bs a bit and fly overhead. I know a lot of the guys I fly with are full of hot air!

ha.ha.. I know a few like that.. I know some hot babes..would they work..?

Originally Posted by stoked6.0

Just get all the guys at the field together in a group and bs a bit and fly overhead. I know a lot of the guys I fly with are full of hot air!

Yeah, and take everybody out for burritos the night before
Dave

I've tried many times to catch thermals over a blacktopped tennis court in my local park.....not usually successful. I have heard that you can catch them over really large parking lots though.

Recently here at the 45th north parallel in Corvallis Oregon, the sun angle is still fairly low at mid-day (like 30deg above the horizon?).

I was out flying my overweight 2M Easy Eagle in some pretty dead calm sunny dry air mid day and just not getting any lift. I decided to try to manuever right off the high start to over a 25ft x 50ft area of black asphalt attached to the bike lane that runs through the center of the field(soccer park) to try to thermal. Fortunately I never tipstalled but it was rather humorous watching a plane that size spinning round and round pointlessly losing altitude in tight cirlces.

So no such luck that day, but I'll try again probably some day with my dinky 37" Guillows Arrow 2ch conversion. Maybe, just maybe.

Adios - Paul

You will kill the grass on a sunny day. Ask anyone who has left a pool cover in one place to long while waiting for it to dry before folding it for storage. The school people will not be happy with you and ban model airplanes.

Not really a thermal, but I saw a picture once of a guy with a leaf blower pointed up and some other guy floating a small glider in the updraft. Technically sloping I guess. It was funny.

If you could get a bunch of your friends to show up at the field with leaf blowers, position them at various spots and............... oh well, just a thought

Rick

Chris:

Many people (including me!) have had that thought. Even so, the asphalt in the next lot over has never yet produced a thermal recognizable to me. The hawks don't fly there, the buzzards don't fly there - so I don't, anymore, either.

We take it as a mantra that sun heating of the ground produces thermals. I suppose it does, but I (for one) don't know which ground is being heated. I take my thermals where I find them.

And, at a new location, I will always go search over the nearest big area of dark terrain, because you never know....

Yours, Greg

I also recall the first time I ever attended a big contest. All day, watching the big gliders get winched aloft, coming down to the landing tapes. Then in the evening there was an impromptu hand launch contest. This was in the days when DLG was just a gleam in the eyes of a few, bold experimentalists. The air was really still, the sun very low in the west.

About twenty guys flew. The first few rounds were designed to thin the field and were the original all-up-last-down: no timing, the first three airplanes down had to leave the field.

About the third round, Joe Wurtz had figured the field out. He put up a three-minute flight, and never circled once. But, he'd coast along over the line of parked cars - that was good for about fifty yards of no loss. Then along the line of barbeque grills - another thirty yards of no loss. And so forth, all over the field. We were all on our feet at the end, yelling and cheering.

Yours, Greg

Originally Posted by 2400RDR

Not really a thermal, but I saw a picture once of a guy with a leaf blower pointed up and some other guy floating a small glider in the updraft. Technically sloping I guess. It was funny.

If you could get a bunch of your friends to show up at the field with leaf blowers, position them at various spots and............... oh well, just a thought

Rick

It we're talking "technically", I think what you describe is more flying on a column on air from a leaf blower than "sloping", lol.

Originally Posted by jrbackus

It we're talking "technically", I think what you describe is more flying on a column on air from a leaf blower than "sloping", lol.

Hahhah- I was thinking "wind" rather than "rising heated air". Whatever- the idea just cracks me up. The picture was a total hoot. It was in one of the archived RC Soaring Digests, and I'd post it, but don't want to infringe any copyright.

Rick

Originally Posted by 2400RDR

Not really a thermal, but I saw a picture once of a guy with a leaf blower pointed up and some other guy floating a small glider in the updraft. Technically sloping I guess. It was funny.

If you could get a bunch of your friends to show up at the field with leaf blowers, position them at various spots and............... oh well, just a thought

Rick

So if the said leafblower was in a truck...cross country????