Scott Johnson sent me this comment from the post about Streamer Recovery on Engine Eject Models:
"I saw another method for tumble recovery rockets as well. The current Estes Mosquito has you rocket air foil its fins (symmetric air foil), which just turns it into a fire and forget lawn dart. However, I saw old plans (it was an old mosquito like rocket on YORP or Semroc) where the fins were airplane foiled (asymmetric air foil), which would cause the rocket to rotate on liftoff and perhaps tumble during recovery."
The asymmetric air foil would make the model spin during boost but probably wouldn't make it tumble down on recovery. If the model were to nose in, it would spin on the way down, nose first. A spinning recovery would slow it down some, like the Gyroc.
Proper tumbling "featherweight" recovery has more to do with a change in the center of gravity after the engine ejects, more like the old Estes Scout.
Estes doesn't use the term Featherweight anymore. Some of the small "tumble" recovery models tend to nose in like the 220 Swift.
The asymmetric air foil would make the model spin during boost but probably wouldn't make it tumble down on recovery. If the model were to nose in, it would spin on the way down, nose first. A spinning recovery would slow it down some, like the Gyroc.
Proper tumbling "featherweight" recovery has more to do with a change in the center of gravity after the engine ejects, more like the old Estes Scout.
Estes doesn't use the term Featherweight anymore. Some of the small "tumble" recovery models tend to nose in like the 220 Swift.
I can't find any kit or plan that shows an asymmetric air foil. I do remember seeing that in the Estes Yellow Pages.
This is from the 1971 catalog.
The original Mini-Brute Mosquito instructions said to do a symmetric airfoil the on fins.
Later on, the BETA Mosquito version suggested you round the fins
To see those instructions, CLICK HERE
Scroll down to the second set of instructions
Scroll down to the second set of instructions
Those instructions were criticized for being too vague.
