new videos to accompany the May issue article - 10/5/11
I thought it was time for a few more videos this time to accompany my article on the stall in RCM&E's recent May 2011 issue. So sit back, grab a cuppa and savour these classic examples......
A powered glider - A lot of the earlier part of the video is out of focus, but later it improves. Its worth watching because the actual mishap is in focus and is an absolutely text book example of an in-turn tip stall. At about 0:50 the pilot goes into a slowish left turn. He is obviusly aware that his altitude is quite low. About 2/3 of the way through the 180 turn he feeds in more elevator – if you watch carefully you can actually see the nose pitch up. An instant later the tip stall occurs.
A P47 this time - No comment on some of the safety practices at start up! At about 2:30 the take-off roll starts. Lift off is a fraction early but would have been OK except that the pilot then heaved back on the elevator. To be fair the model does its very best to forgive him! After each stall, I count a total of four, the aircraft tries to recover but the pilot still has all that up elevator in, so each recovery simply leads to another stall until eventually the model goes in. Interestingly the pilot’s first reaction is “radio failure” – his co-pilot however quickly corrects him!
A nice E-flite DH Beaver with floats - The model seems a bit marginal on power and non-to-well balanced. At about 1:30 the pilot loses a lot of height in a left turn. In the subsequent attempt to gain height, via the elevator rather than the engine, he ends up with a very large AoA and the left wing tip stalls.
Speed! - Some stalls are relatively slow and leave you with that powerless feeling as the model seems to go in almost like it in slow motion with the pilot fighting all the way down. Some are frightengly fast, blink and you’ll miss it. Here is an example of the later. A MIG15 EDF, I assume this was a maiden flight, at about 0:50 the pilot slows the model down presumably to investigate the stall – he finds out all he needs to know about it when it tip stalls and flips inverted on him. Undaunted he goes on to carry out his landing and guess what? Yeap, it does exactly the same there. You’d need reactions like a cat to sort that one out!
To finish off with, a happy ending! Three tip stalls for the price of one! And a remarkable recovery!
That's it for now but don't forget to leave your comments and suggestions in the forum thread below - it's always great to hear your thoughts and suggestions.
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