stewart grant Posted January 16, 2011 Share Posted January 16, 2011 What is it about aeromodellers and the effect of wind on an aircraft? I've just looked on the forum regarding this and most of it is wrong! Wind does NOT effect the airspeed of an aircraft. When a model is travelling downwind the GROUND speed increases. The airflow over the wing stays at the same speed assuming you hav'nt changed the attitude or throttle setting. The rubbish that even experienced modellers spout about wind and airspeed is pathetic, even instructors and examiners seldom understand this fundamental of flight. Gusts and wind gradient are variables in terms of AIR speed but are easily explained if anyone is interested. The reason a model apparently climbs into wind is because its already trimmed to climb! Its just travelling slower relative to the pilot on the ground so it has more TIME to climb. When travelling downwind its moving faster over the GROUND so its got less TIME to climb before the neccessary turn. Plus the angle/perspective can be different and the model APPEARS not to have climbed as it may have travelelled further downwind because of the GROUND speed. PLEASE STOP perpetuating this myth that wind increases or decreases airflow, lift and control response of an aircraft in flight. Quote Link to comment Share on other sites More sharing options...
r6dan Posted January 16, 2011 Share Posted January 16, 2011 Quote Link to comment Share on other sites More sharing options...
PatMc Posted January 16, 2011 Share Posted January 16, 2011 Is this a 5 minute argument or the full half hour ? Quote Link to comment Share on other sites More sharing options...
John Privett Posted January 16, 2011 Share Posted January 16, 2011 You're right Stewart, and it's a discussion that rears its ugly head from time to time on here and other forums, and usually goes on to fill page after page... But still a significant number don't "get it" and go on to perpetuate the myth of "the dreaded downwind turn." Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 16, 2011 Share Posted January 16, 2011 Welcome to the forum Stewart. Although it is more customary to introduce yourself before launching into a heated post. BEB Quote Link to comment Share on other sites More sharing options...
Alan Cantwell Posted January 16, 2011 Share Posted January 16, 2011 cor, nice 1st post, you know, this reminds me of an instance eons ago, skyways models mewgull, OS61fsr, well throttled back, going downwind on a breezy day, says me, you could do with a tad more power on, says him, listen laddy, (i was 40) if you dont tell the plane its going downwind, it wont know, seconds later, it tipstalled, and went in vertical says me, dont tell it it crashed, and it wont know Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted January 17, 2011 Share Posted January 17, 2011 Stewart, I fully agree with you on this but it's a recurring theme, both at club level and on the forum and very difficult to shift entrenched attitudes. People see models crashing during downwind turns or zooming when turning into wind and simplified logic provides an easy explanation which is totally incorrect. The other main reason for these effects is expectation of the effects of turning relative to the ground leading to pilot inputs causing these apparent effects. Quote Link to comment Share on other sites More sharing options...
BB Posted January 17, 2011 Share Posted January 17, 2011 Posted by PatMc on 16/01/2011 22:43:32:Is this a 5 minute argument or the full half hour ? Reckon he might be going for the full on punch-up in the car park Pat Watch this space I guess. Excellent 1st post Stewart BB Quote Link to comment Share on other sites More sharing options...
Andy Green Posted January 17, 2011 Share Posted January 17, 2011 I'd reccommend any flyer buying a copy of Stick And Rudder. Andy Quote Link to comment Share on other sites More sharing options...
Steve W-O Posted January 17, 2011 Share Posted January 17, 2011 And Einstein may ask if Birmingham and Manchester stop at his train. I think most people know the true facts, but the concept works to explain what happens and how to avoid it, and that is what really matters. Most modellers are hobby flyers, not professors of aerodynamics or anything. It's said that those who can't do it, teach it, and those who can't teach it, teach the teachers. People who fly models are the one who can do it Quote Link to comment Share on other sites More sharing options...
Klippy Posted January 17, 2011 Share Posted January 17, 2011 This argument is at least 40 years old, the model is flying in a box of still air, the box of air is moving downwind at wind speed. The apparent balloning when you turn on to finals is attributed to the eye/brain taking a few frames to appreciate the change in apparent airspeed. (ducks back behind the wall!) Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted January 17, 2011 Share Posted January 17, 2011 You know this is not confined to modellers. Some years ago I read an accident report from America where an aircraft had turned back and then crashed. The accident report from the crash investigators blamed the down wind turn...But then, they were American. Quote Link to comment Share on other sites More sharing options...
alula Posted January 17, 2011 Share Posted January 17, 2011 Wind does NOT effect the airspeed of an aircraft. You sure about that.. dynamic soaring . doesnt the glider increase in speed as it hits the lift again. Isnt lift wind... Quote Link to comment Share on other sites More sharing options...
David perry 1 Posted January 17, 2011 Share Posted January 17, 2011 Posted by PatMc on 16/01/2011 22:43:32: Is this a 5 minute argument or the full half hour ? LOL! D Quote Link to comment Share on other sites More sharing options...
Bert Posted January 17, 2011 Share Posted January 17, 2011 +1 for R6dan Don't feed the Troll! Bert Quote Link to comment Share on other sites More sharing options...
MarkyMarc Posted January 17, 2011 Share Posted January 17, 2011 Woo Hoo! Stewart, welcome to the forum - I trust you will find everything to your satisfaction. ps You don't have to sit on the fence!! Quote Link to comment Share on other sites More sharing options...
Lee Smalley Posted January 17, 2011 Share Posted January 17, 2011 absolutely world class R6Dan can't stop laughing Quote Link to comment Share on other sites More sharing options...
weasel Posted January 17, 2011 Share Posted January 17, 2011 Stewart, Read the thread "gusts and stalling" and you will see how heated the debate got. But in the model world so long as they fly i dont think this is a great issue. Just my two penny"s worth. Cheers Weasel..... p.s Hope you enjoy the friendly forum..Edited By Biggles' Elder Brother - Moderator on 17/01/2011 23:14:56 Quote Link to comment Share on other sites More sharing options...
Ernie Posted January 17, 2011 Share Posted January 17, 2011 Here we go again....Surely you launch with the wind directly behind so that the mopdel goes faster, and the lifting molecule things are more efficient ernie Quote Link to comment Share on other sites More sharing options...
flytilbroke Posted January 17, 2011 Share Posted January 17, 2011 The Right hand adverts are again on top of the thread. Hmph. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted January 17, 2011 Share Posted January 17, 2011 alulaDefinition from Wikipedia "Dynamic soaring is a flying technique used to gain energy by repeatedly crossing the boundary between air masses of significantly different velocity".No mention of the word "lift".Watch the vids on youtube, they fly on the down wind side of the ridge. Quote Link to comment Share on other sites More sharing options...
David perry 1 Posted January 17, 2011 Share Posted January 17, 2011 Posted by Ernie on 17/01/2011 17:32:10: Here we go again....Surely you launch with the wind directly behind so that the mopdel goes faster, and the lifting molecule things are more efficient ernie I always launch mine with the wind from one side. That way the models tendancy to go sideways counteracts the earths spin and the plane goes straight. Never fails. D Quote Link to comment Share on other sites More sharing options...
John Privett Posted January 17, 2011 Share Posted January 17, 2011 Posted by flytilbroke on 17/01/2011 19:30:05:The Right hand adverts are again on top of the thread. Hmph. Yep... MODS... The problem is in "weasel"'s post at 12:56:30. On the first line, following "Stewart," there are about 140 non-breaking spaces ( [semi-colon] ) which are the achilles heel of this forum and muck up the formatting of the first page. Delete everything on that line to the right of the comma and we'll be able to read the earlier posts in their entirety rather than guessing the missing words (or cheating by reading the page source - but that's a little tedious!) And once again, PLEASE can we have some validation (in the forum code) on the input to stop this happening. It's not difficult. Edited By John Privett on 17/01/2011 23:09:04 Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted January 17, 2011 Share Posted January 17, 2011 Thanks for pointing that out John - sorted! BEB Quote Link to comment Share on other sites More sharing options...
alula Posted January 18, 2011 Share Posted January 18, 2011 Simon . yip my mistake.. so different velocity . does that relate to wind velocity,. ie speed. Quote Link to comment Share on other sites More sharing options...
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