Hi,

My WH Egde 540 requries about 1.5 degree up elevator to fly level (5 clicks up trim). Otherwise, it flies "nose heavy". Because the incidence of the wing, the stab, and engine is set at 0 degree , I would think the amount of up elevator is too much.

Just wonder if your Edge 540 requires up trim. I have set the CG at 5 inch behind the LE.

Appreciate any input.

--qc

I have my CG at 5 1/4 back and the elevator is flush with the H-stab. It takes just a hint of elevator when inverted for level flight.


Verify you CG it sounds nose heavy big time.

I agree with Mark. If you're needing up trim the C/G is probably not where it needs to be. It's flying nose heavy because it is nose heavy.

Your motor set at zero degrees of incidence may be causing you to need the up elevator trim.
Try these simple test. A long power off dive straight down. Does it start to pull toward the canopy?? Next come across the field in level flight at wide open throttle, throttle back to idle. As the Plane slows down does it start a slight climb or nose up attitude? If it does either of these then change your motor incidence to 3/4 to 1 degree of up incidence. This will most likely allow you take out the up trim in the elevator, which in turn will also help your inverted flight also. On my 28% WH Edge and my Hangar 9 33% Edge both motors are set up with just under one degree of up incidence. As others mentioned you may also want to rethink your CG. The WH Edge loves to fly tail heavy. To set up for a landing I am pushing down elevator just up to the point of touching down. Good luck.

Gary M

Hello All,

Thanks for the feedback.

I did some more trim tests per Fly Cirkus's video on trimming. On 45 degree inverted upline, the plane shows some sign of tail heavy (flying toward canopy). On inverted level flight, quite amount of down elevator is needed. Since the CG (5") is well before 25% MAC (5.25"), I would agree with Gary that some up thrust incidence probably is needed. I've added about 0.75 degree and will report the result.

By the way, the two washers were made out of thin stainless sheet found on old 3.5" floppy disks. Pretty thin and allow accurate adjustment. This time, I added just one washer per standoff.

--qc

On my edge,when i go inverted,i use a touch of down elevator to level the plane,then i can let the sticks go and she will fly level.I think thats about how it should be.

I flew the Edge today (with thrustle incidence angle raised 0.75 degree). It improves just a little bit and about same amout of up elevator is still needed. However, the roll on upline looks more axile. So it is a keeper.

We also did a static CG test with fuel in the tank and the plane is defnitely nose heavy. Plan to move the CG to back to 5" 1/4 as suggested by mstroh3961 to see what happens.

--qc

Nonstoprc...
Static CG checks are done typically without fuel, as most instruction state.
Though the fuel is not far from the CG location, it will make a difference, If
it's a 16oz tank, that's one whole pound.
You didn't say what motor you are using or where you have your radio gear
located. I'd say to move the CG back the recommended 1.4" and try it there.
When your CG is right, the elevators will line up correctly.
You might also check your firewall for corect vertical position. Tom's planes
are right on, normally, but it doesn't hurt to make sure.

Gerald

Yep, I have to agree never CGthe plane with a full fuel tank. THe reason is that when you start emptying that tank your CG will shift to a tail heavy plane. If you get to low thenand to tail heavy you will be in for a real bad time.

I know with my Edge I went to a smaller tank. 16oz. and got it right on the wing tube area. It flew really nice with it there.

I'm soooooo glad I stayed out of this after my first reply. Setting a C/G with a full tank???????????? Wow,... problems assured.

Set the dang C/G at the Mfg suggested point and move it back until it flies level in upright flight at neutral elevator trim. Too easy.

I am using a 20oz tank and the CG testing was done after landing. Because of extra fuel in the tank, the plane is "nose heavy". With 10 minutes of IMAC style flying, there is about 5-7 oz of fuel left in the tank. I am considering switching to a 16oz tank. Any idea on the max time I can have with 16 oz tank?


I think it is OK to place the tank right on CG as most pattern flyers do. The problem is how far back it can go. I've tried 5" 1/4 behind LE yesterday and the plane is definitely flyable, though the up trim on elevator is still needed.

I am looking into other problem areas. Looks like incidence on wings may not be right as measued. Setting the Robert meter on the root section of wing, I got a reading of -0.75 degree. On the middle of the wing, it reads 0 degree. So some kind of warp is going on. A negative incidence on wing definitely explains the "nose heavy" problem. I would think the measurement on root section is more reliable?

BTW, the engine is a DA50.

--qc

I think I need to go back to work and stay away from this one, but I just can't do it.

The tank location is just fine. Especially if you slide it bach far enough to stop against the receiver tray. The wing incidence won't make a hill of beans difference at 3/4 degree.

My thoughts are that if you want the perfect "pattern" plane, prepare to spend a few thousand dollars for just the airframe and then go fly pattern. If you want to fly IMAC, then be prepared to actually have to be personally involved in he flying and set up of the plane.

As far as the plane being "definately flyable", you're darn right it is. You just have to be good enough to recognise it and have the ability to do it.

Harsh perhaps, but fault can always be found anywhere you look hard enough.

Flew the WH Edge 540 today with the wing incidence raised 0.75 degree (0 degree, match with the deck-line), and elevators set at neural. The "nose heavy" feeling is completely gone. The horizontal line is as straight as it can be. No up-elevator trim needed at all. I would think the problem is fixed! Tried IMAC 2006 sportsman sequence and it flew definitely better.

The lesson learned: measure the incidence at the root of the wing.

As far as pattern or IMAC style flying is concerned, I would think, as remarked by top TOC/F3A competitors, removal of any bad flying characteristics is a necessity. It makes pilot's job easier.

--qc