Posted Wednesday, May 6, 2009 @ 11:50 AM
For the typical RF5B owner (this excludes Rudy with his ship that climbs like a rocket), climbing in the RF5B at high density altitudes can be entertaining....or the cause of white knuckles depending on what you're seeing through the canopy.
My RF5B usually climbs well to 800-1000' -- but can climb at a leisurely pace after that. If I am trying to make altitude to fly over nearby mountain passes, this is no small challenge -- especially in hot weather. If you just engage the climb prop, you just overheat the engine.
The following formula seems to work.
With the prop in cruise pitch:
- increase rpm's to 2,800.
- trim the glider for max level speed.
- now add upward elevator trim.
- apply gentle forward pressure on the stick so you keep 78-82mph
This get's you enough speed to keep the engine cool. You're not getting on the back side of the power curve. In fact, you're almost keeping it level -- but the upward trim gets you a steady climb.
I find that depending on the actual temps, glider CG and the Humor of the Gods for that day -- the specifics will vary a bit to get the best climb. But the basic technique works. It's the only way I've gotten a steady, reliable climb for thousands of feet without overheating the engine.
Good luck.
