capt17

Hi folks, Just need some input on the Great Planes Corsair 40 CG. I built and flew this plane once last year and it looks great and flys well but is way heavy. I did tomany mods to it, but you live and learn. That's what the hobby is about. Anyways she weighs in at 8lbs. Heavy for this bird. Great Planes says the CG is at 3.5 inches from the leading edge. That's where I have it balanced but I had to add a half pound of weight to the nose to do it. So my question is If I were to move the CG aft say half an inch, thus allowing me to drop a lot of weight up front, how poorly will my plane react? I'm just trying to tame down the landing speed a bit.

Note: I balanced this plane with my retracts up, which is why this is plane needed so much weight up front. Was this correct? Obviously with the gear down the CG changes drastically towards the front.

Thanks!

Dash7ATP

What did the directions say about the gear location when setting the CG?  Setting it with the gear up on a Corsair would be the safest optioin if it's not memtioned. 

Moving the CG aft on a model of that size could have a big influence on it's stability. I'd only move it 1/4 inch at a time to be safe.

Dash

91zulu

My Feedback: (2)

With trims at neutral how does it fly gears up ?

capt17

Zulu, It flys. I've only flown it once about 10 months ago and it was cold out so I didnt want to put too much time on it. Then life got in the way and prevented me from flying it anymore last year. Anyways, if I remember correctly I kept it a little hot and high just to be safe but didn't do too much more than putter around the sky. Really I just want it to be a fun plane. No areobatics needed for this plane, I've got others for that sort of stuff. My landing was hot and I just want to loose a little weight before I try to land again. Thanks for the help!

91zulu

My Feedback: (2)

Ok reason I ask is I wanted to know if you had to adjust the trims while flying, that is up mainly. If you did then it is possible you can remove some of the weight a little at a time. Maybe 1/4 oz at a time. Half inch is a bit to move at once, can result into a very busy take off that can end bad. This is what you do, turn on your Tx, then rec in the plane and take a look at the elevator. You are looking to see if there is up or down in it from your last flight. If it is up then remove 1/4 oz, reset trim to neutral then test fly and take note what it takes for it to fly level. Now this is just a ruff test, taking into account engine thrust is right as per instruction, everything is straight and wind conditions. If you still need up trim, then remove another 1/4 oz until the plane flies level at neutral trim down wind. Depend on how heavy the wind is blowing it may tend to climb up wind, not to bother with that or you will be chasing the trims up wind and down. Now as you remove weight pay attention to your take off , don`t yank it off the ground try to do gradual climb outs until the gear retracts. Same on landings keep the nose down a bit on approach. Once you find the sweet spot, go up high bring the gears out and reduce the throttle to get a feel how slow she will fly before she stalls and use that rudder it is your friend at that weight. Do a bunch of touch and goes so you can learn how to bring her in at a decent speed. Let us know how it goes. Its not that bad, now if you were over 10 pounds then that would be different.

capt17

Thanks Zulu.  It will probably be a few weeks till I get the chance to re-maiden her for this year since Indiana still has a bit of snow cover and we're supposed to get more this week..Thanks for the advise.  I will certainly look at the elevator trim setting when I get home in the morning.

91zulu

My Feedback: (2)

Sure thing let me know what you find.