sodbuster 1

Have a Great Planes Giant Aeromaster with a new DA50 in it.
Am running a XOAR 22x8.
When you cut power on landing approach, it's almost like someone thru out an anchor.
Seems to lose all airspeeed.
Any prop suggestions would be appreciated

arobatx

You can run a 20x10 or 22x10....and that might help a LITTLE. But its mostly the design of the airframe, and all the drag. I'd stick with the prop you're running, You'll need to adjust your landing habits, and keep power on until the last moment.

drbruce

I used a Mejlik 23x8. Seems to be the perfect prop for my DA50. It loads up the engine quite nicely.

sodbuster 1

what airframe are you flying it in?

Zeeb

My Feedback: (41)

That's one of the NICE things about running gassers with big props...

As others have mentioned, you just need to adjust your landing technique. Bipes will decelerate more than a monoplane anyway, but when you start getting into the bigger models and gas engines, it is usually desirable to learn to do a "slow flight" landing. That is a higher angle of attack and carrying a bit of power. The model will actually fly slower that way than it will in a glide. Then when on approach, you control altitude/descent rate with throttle not elevator. If it's sinking you just blip the power, if it's too high just pull it back a bit. Then going to idle on rollout shortens that rollout considerably.

Do bit of practicing, once you get the hang of it I think you'll really like it....

JMHO, YMMV....

sodbuster 1

Thanks Zeeb.
Will give it a try.

Either that or throw a mattress out onto the field lol

Zeeb

My Feedback: (41)

Well it does take a bit of practice, so I suggest you start up high and try establishing a slow flight condition. Now I'm not talking about high alpha 3D stuff here either....

It'll show you how the model handles in that flight realm and it's something they spend a chunk of time teaching students when you go for a full scale pilot license. That's also one of the places they point out that throttle controls altitude and elevator controls attitude, the classic problem they're trying to get away from is the stall. Lots of model flyers refer to it as a "tip stall" and I suppose that's a good description for what happens. In full scale, the wings are "washed out" so there is less angle of attack at the tips than the wing root and so when it stalls, that happens at the wing root and moves outward to maintain aileron effectiveness as long as possible. It will also teach you about the rudder if you don't already know, it's much more effective than the ailerons for controlling the direction and it will keep working after the ailerons lose their effectiveness. Great little tidbit for your crosswind landings as well.

So since models don't have that washout, when you stall the wing it happens at the narrowest chord, the tip. If that happens, the thing will snap and it's caused lots of grief for guys transitioning from smaller glow stuff to the higher wing loading found on Extras, Yaks and the like. Your model is not as prone to that, but it will do it if pushed hard enough.

What you'll learn initially is what the full scale folks call a "soft field" landing, then later on as you get the hang of it you'll start doing what they call a "short field" landing. Soft field is nice and gradual descent where a short field drops like the proverbial rock, but the airplane is flying slower than a glide with both methods. I almost always fly a pattern to land just like the full scale guys as that gives you a more or less constant frame of reference for your height and approach/glide distance. Later on, you'll get so you don't need to do that but it works great for bleeding off speed in the turns and setting up the short field landing technique. THAT'S where a tip stall will get you if you don't know your model well.

Sorry about "going on" like this, but we're just borrowing some full scale techniques for our smaller incarnates, but they're still airplanes.

Have fun and remember two mistakes high for your slow flight practice....[8D]