Aerobatic in a decathlon

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FLYBOY532TD

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Hi I am a owner of a 1971 Decathlon 150cs. I have had the plane for two years and been flying the sportman series. I am checking to see if anyone has a technique for flying the avalanche(a snaproll on top of a loop). I have been trying the avalanche by entering the loop at 160mph but halfway through the snaproll it falls out into a spin. Does anyone have any suggestions? I pull approximately 3-3.5 Gs on the loop. Should I pull harder or fly faster? Any information would be helpful. Thank You.
P.S. Has anyone ever did a flatspin in a decathlon?
 
I don't snap my '79 150 hp F/P Decathlon but I don't mind doing an avalanche occasionaly as the speed is low at the top.
160 mph should do it, pull about 4 g. Start it early. Use rudder & aileron.
 
From Alan Cassidy's book -

Normal loop entry speed plus 20mph

4 - 4.5g on the pullup

Practise loops so that you are still pulling 2 - 2.5g at the top of the loop

For the Avalanche - as you approach 30 degrees nose up inverted, apply full rudder and almost immediately unload the elevator to just forward of neutral - don't forget, you unload on a normal flick, once it has commenced, add a little aileron on the same side as the rudder - not too much.

Stop by applying full opposite rudder and centralise the control column - don't apply forward stick as it will flatten the loop

Once stopped apply back stick to complete the loop.

Alan has been British National Champ on several occasions and writes a good book. This is from Better Aerobatics ISBN 0-9544814-0-2.

The other excellent book is Flight Unlimited by Annette Carson and Eric Muller - very easy to read and an excellent source work. Flight Unlimited can be difficult to find as it only prints occasionally but worth tracking down a copy.
 
I also don't do snaproll in my decathlon except when I try an avalanche. I thought that the speed would be slow enough that it shouldn't be a problem for the decathlon. Thank for the info.
Pat
 
For an avalanche I use an entry speed of 160mph. 4g pull up. Look over the top of the loop and begin the snap about 30 degrees before the plane would be level inverted. When you pull the elevator back for the snap, make sure you don’t bury the snap, or you will fall into a spin. You need only pull back quickly to stall the wing, and then go forward with the stick. (Practice this in level snaps and you’ll see that this really increases your rate of rotation, and gives you much more energy to work with when you want to stop the snap) If you start 30 degrees before level inverted, and don’t bury the snap, you’ll end up being able to recover at about 20 or 30 below level inverted and finish the loop. If you begin the maneuver at more than 160, you’ll be able to work all those numbers closer to level inverted. Have fun!

Aaron
 
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