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Archive for May, 2016
Posted by phil alvirez | May 27, 2016 @ 08:41 AM | 6,400 Views
am in the process of evaluating lifting stab on 2 meters sailplanes. my goal is to use them for thermaling. not competition; to be able to stay up longer with less effort.
but above all, if it is easier to detect thermals and if a plane can be trimmed so if it senses a thermal stays there, like the free flight planes do.
also, i am trying to stablish a comparison: how a lifting stab influences the flight? stability? under power? does it help make the airplane more thermal efficient? easier to detect thermals? does it increase drag too much?
all of this will be tested in a future.
if you are interested, keep looking into this post. will be updating it at the end.
r/c models of all kinds use flat or symmetrical stabs that do not generate lift at zero degrees of angle of attack.
in ancient times, guys that flew free flight duration began using flat stabs. until some1 'discovered' lifting stabs, and from then on, all the planes use it. even to this day the indoor free flight power (rubber) use them. all of them.
there was a guy who collected plans from all over the world, together with comments of their designers, and published them. even wrote a detailed study and showed it on his books of 1951/52 (pages 5 to 20), and 1953 (pages 3 to 18). his name is Frank Zaic, and all of this was widely discussed and used by everybody-including all the experts and those who won all the competition for many years.
these books still can be reached by google.
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Posted by phil alvirez | May 11, 2016 @ 09:41 AM | 6,287 Views
yesterday when i looked from my window at the trees nearby checking the wind, i noticed some movement on the grass. it was covered with yellow flowers, but some seemed to be in motion. so watching more closely i saw 2 canaries: 1 with the head and wings of dark color, the rest bright canary yellow. the other with just a few dark feathers so it was mostly yellow. nice sight. they were picking something (seeds?). then the darker found a puddle where took a bath. funny the way they do that. suddenly both took off. i never saw canaries flying free, only in cages. and with winter so cold here this was the last place i could imagine seeing them. perhaps came from the south as the temperature is now above freezing and are becoming sort of migratory birds too. perhaps escaped from their cages and learned how survive in the wilderness. grown in cages, most birds if get free often die as dont know how to find food and water. so it was a pleasant surprise i would say. it is 1 of the wonders of this spectacular land of the north, always full of surprises. (although some are not very welcome, like tornados and storms).