Ola Fremming's homepage


Hints to ease hovering

When one starts to learn the art of hovering with a plane, it's hard to know what's right and wrong in model setup and flying technique.  From my limited experience, here are my findings :

  • Fly smooth, rapid changes in throttle setting makes it very hard to hover, since the torque and control sensitivity changes all the time.

  • Try in dead-calm air, it's much easier then.

  • Fix your eyes on the front part of the model, not the tail.

  • The lower and closer is easier (but more dangerous), you see better what's going on.

  • Engine thrust must be offset quite a lot to the right, and if needed also some up.  By fine-tuning the thrust one reduces the workload during hover.  Work on this until it hangs stable in dead-calm air without any control-input.

  • If you have problems of getting enough up-thrust some elevator should be trimmed in for hovering.

  • CG, move the CG as far back as you can while still being able to fly it.  My TopCap was a pig to fly straight and level with, but who uses a TopCap to do this ?  When on approach I had to push, to keep the nose down and maintaining some forward speed.

  • Try different propellers, I tried several, and ended with APC-12x6 and/or 13x4.  To pull these (at least the 12x6) you need a 50 size engine, a normal 46 will not do.

  • Use several flight-modes, to optimize settings for different kinds of flying.  I use a Graupner MC-24 transmitter, the big bulky European style, similar in functionality to JR PCM10-SX.  On left stick (thr. & rudd.) I have a 3-position switch to select the 3 flight-modes that I use.

Center, normal : for normal type of aerobatics, take-off's and landings.

Down, hover  : Max deflection on ailerons, more than normal on elev. & rudd.  Apply a suitable amount of expo to be able to fin-adjust while still having max available for 'crisis'.

Up, insane  : Max on all surfaces, to do all kinds of crazy stuff.  In this mode models usually are more or less hopeless to fly straight.

  • A tendency to roll right (against engine torque) is probably because of uncontrolled descent.  I noticed this, when I first tried to back down to lower altitude, it's because of the ailerons getting air from behind and changes direction of force (check in static mode, and think).  In normal hover small 'blips' of right aileron should be sufficient to avoid torque.

  • Best entry : A slow and low close pass at idle.  Start pulling up, while smoothly and gradually increasing power.  When properly done, one should end up with needed power and zero forward speed in 3-4meters (or less) altitude.