I was just wondering what some of the Bros do with a new plane to get it "sweet". I had my last Extreme 330 pretty much there after flying it off and on for a while, but I don't really know how it got there. I just put a new one together to have something to fly this weekend (great weather, maybe the last great weekend of the year) and it's flying about like my last one did six or seven months ago.

I guess I'm wondering if folks have a step by step procedure they follow with a new plane. I know mine's a bit nose heavy and it needs a little weight on the left wingtip; I'll work on those, but what comes next? I've seen a bunch of pattern trimming charts... Are they applicable to profile planes and the type of flying we're doing? OR is there a better way?

I figured this would be the best place to learn about this, and I'm sure I'm not the only Bro who could use some education on the subject...

Where's Bayside hroachen? I live in Rochester if you know where that is, maybe we can do some flying.

Bayside is in Queens, right by the Throgs Neck bridge. Mapquest says it's a 5 or 6 hour drive.

This is so much easier with the trasmitter in hand, but here goes:

Do normal flight trim.
Pull vertical and go straight up, if it pulls to the left, add right thrust. You must do this first, do not try to trim it out in rudder, or you plane may never hover well.
Try positive and negitive snaps to look for bad traits.
Knife edge flight to see if its going to pull or push, or what ever. May make mixing ajustments, however now I just fly it that way. Most don't need much.
Inverted flat spin to see if I have enough deflection. Planes should invert flatspin with enough deflection, doesn't need to be very tail heavy.
Hover. If the nose drops out easy, add tail weight until satified, then move battery for balance and eleminate weight.
Do a parachute to see if a wing drops, and to see if the horizontal stab is going to eject.

This takes several flights and make ajustments every flight. This may take 10-20 or more flights. Look at different amounts of deflection, expo, spoilerons, flaperons and the percentage of those. Also look into props, those can make a big difference.

Just play with it. You should not do anything that would make the plane much more difficult to land. Make small changes and several flights.

1

Here's where I'm at now, this after maidening the plane yesterday:

My first impression is that the plane is tailheavy. My first Extreme had no additional weight for balance, but the plane ready to fly weighted 5.2 lbs. This one came in at 4.6. I know the engine and radio gear weighs the same as before, and everything's in the same place, so the difference is airframe weight. Most of the airframe is behind the CG.

The in-flight symptoms:

1. Trimmed for level flight at half throttle upright, it needs around 1/4 stick forward to hold level inverted.
2. Trimmed for level upright flight at half throttle, put the plane into a steep dive. As the speed builds, the plane pulls out of the dive on its own. I'm concluding that the up trim to hold the nose heavy condition is becoming stronger as the speed builds, but since the weight in front stays the same the plane pulls up as the speed increases.

Wingtip weight: If I place the plane upside down it won't balance on the fuse, the right (engine side) wingtip falls to the table. Even if I put the left wingtip down, it falls back over to the right. Doesn't feel off in the air, but I'll put a bit of weight on the left tip to get it into balance anyway.

The plane doesn't seem to want to fall out of a hover in any particular direction. Leads me to believe the thrust line is close to correct. I might have to increase right thrust once the weight is on the left wingtip, we'll see later.

I set the ailerons to be level with the centerline of the wing chord. I know some are setting them to follow the line of the bottom of the airfoil, but I tried that on my last Extreme and I liked it better with the ailerons level. Is there a definitive test to determine where the ailerons need to be?

Thanks,
David

When setting the ailerons I like to put the plane in knife edge flight and see if it pulls towards the belly or canopy. But I flew a guys Extreme 330 the other day at our field and he had the flaps on a dial so I continued to dial in reflex until the plane tracked straight in knife edge. When I landed the plane and looked at the ailerons I couldnt believe how much reflex was in there...........way too much. Im not sure what was wrong with his plane but it definately didnt trim out like my Sledge did. With my Sledge I can raise or lower one aileron only a few clicks them retrim for level flight and it makes a huge difference im knife edge......go figure.

I don't know if knife edge would be the best test for setting the ailerons. I'm thinking something along the lines of doing upright and inverted harriers and adjusting the reflex until both feel about the same. I could be wrong but I'd imagine a lot of reflex (ailerons up) would make upright harriers a breeze but make inverted ones pretty nasty. Right now my Extreme feels close to the same in both upright and inverted harriers. It doesn't lock in quite like my old one, but I think it'll get better when the CG comes back.

Both my Extremes tuck to the belly with rudder in a knife edge, but I noticed something interesting on the second one... with small rudder inputs it will just hold knife edge at high speed... and with small rudder inputs it has a mild pull to the canopy. If I go to bigger rudder inputs then it tucks to the belly, full 3D rudder in the knife edge produces an outside snap roll.

I'm thinking that when I get the CG back further the plane should knife edge better on smaller rudder inputs, thus getting rid of the coupling problem. When the CG comes back I'll be able to get rid of some of the up elevator trim thats in there now, so the pull to the canopy should go away. And with the CG back I shouldn't need to get into the big rudder inputs for knife edge.It pains me to admit it, but I never really tried knife edge with smaller rudder inputs on the first Extreme, I never bothered to set a low rate for rudder, just ailerons and elevator. The new one has hi and low rates set for all the axes.

We'll see. More testing/trimming to come. Tomorrow looks like flying weather.

Got some more trimming in. Things are starting to make more sense. I added an ounce to the tail, took out some of the up elevator trim. It'll fly hands off level, still had a bit of forward stick to maintain inverted. Knife edge on small deflections got easier, plus less up trim on the elvator took out the pull to the canopy. Added another ounce to the tail, got the elvator almost dead neutral now. Upright and inverted almost hands off, with the elevator neutral trimmed it's not feeling the same both upright and inverted, it descends a bit moe inverted hands off than upright. I think I want to keep the elevator trimmed dead neutral and get the plane to feel the same upright and inverted with the aileron rigging. Then sneak another half ounce in the tail to get it to stop descending. It'll knife edge to the next county with only rudder input now, no more pull to the canopy on small rudder deflection knife edge. Has a slight roll to level with rudder, should mix out very easily.

The plane still gets weird on bigger rudder deflections. Tucks to the belly and will snap out of knife edge with enough rudder deflection. But with the CG aft there's no need for big deflections. It'll knife just fine even at somewhat slow speeds on maybe 20 degrees of throw. Haven't tried to go all the way round a KE loop yet, it's been pretty windy, but it goes up and over the top easily so far. Harriers and waterfalls are definitely easier with the CG back.

Gonna have to get another degree or two of right thrust in it, it seems to fall to the left consistently in a hover, but I'll wait til a calm day to be certain.

Landings need some down elevator on approach or it drops the tail as it slows. I can live with that. Harrier landings are pretty much hands off now unless it's gusty.

Great info! Thanks for the detailed report. I have one of these that WOW-OOPS gave me. I have straightened the fuse from one of his previous repairs. All I have to do now is cover the area and install my gear and I will be ready to go. What was your final CG and right thrust amount?

Jeff

I don't think it's finalized yet, but it's at 6 1/8" from the LE at the root right now. Right thrust is just what was built into the rails at the factory for now. I'll grab some thrust wedges tomorrow (they come 1, 2, and 3 degree in the package) and try the 2 degree next time out.

Word of warning... I haven't flown it at 6 1/8" yet, I added a half ounce more in the tail to arrive at this setting. The previous flight the plane still descended slightly both upright and inverted so I added the extra half ounce. I must say that the plane was getting quite pitch-sensitive with just the two ounces in back. It might prove to be a handful with 2 1/2 ounces back there. I have decreased my elevator throw on low rate and gone softer on the expo for both lo and hi rates. The plane hadn't gotten into pitch instability yet, but I can feel that I'm sneaking around close to that territory.

Forecast is for rain tomorrow, but maybe I can get some air time in between the showers...

D