splais

My Feedback: (25)

I tried to maiden flight my ESM 71" FW-190 with a DLE30 this morning. It was near disaster. Ground handling, taxiing, takeoff roll were all ok. On lift off, the minute gear cleared the ground, the plane banked hard left. I barely got it back on the ground before smashing into fence. I've flown warbirds a lot. Had planes that were hard to takeoff, planes that stalled, etc; never one that did this. After action inspection showed something I had not noticed. The two elevator halves were off about, I'm guess, 2-4 degrees in the direction that would make it roll left, so I have two questions: (1) could the elevator have been the problem with this small a differential?; and (2) anything ese could cause this? Thanks.

All Day Dan

My Feedback: (5)

Did you follow your RC manufacturer's instructions how to install the airborne system? Did you comingle the ignition system components with the RC system components? Did you do a thorough range check? Dan.

splais

My Feedback: (25)

Yes,no,yes Dan - thanks for the help.

wphilb

My Feedback: (10)

Check over everything, especially balance, the fix the elevators and build in a touch of right ailerion trim. Now fly again making sure you have sufficient ground speed prior to lift off. 

splais

My Feedback: (25)

yes, on retrospect I'm thinking maybe I did not build up enough airspeed before lifting off. It weighs 17 pounds with 1 pound of lead in the nose.

OldScaleGuy

My Feedback: (2)

One other item to check is the incidence of the horizontal stab. All the surfaces are going in the correct direction, lefts are left, rights are right. Right? Glad you were able to save it...!

invertmast

My Feedback: (23)

Sounds like a typical, yank it off the ground befor its ready takeoff to me. Lack of fammiliarity with the plane is the most commin reason for this.

Is this your first largish model?

da Rock

Could the elevator offset cause this? Yes, but probably didn't. It probably only helped it happen. Although, 4degrees is a fair amount. Check your servo strength after straightening out the alignment. Servos that've been in a crash might have lost some internal grip and could slip under stress.

Heavy wing loadings help also.

Sounds like you've gotten advice on enough things to do.

kahloq

3 blade prop is producing a lot more p-factor relative to a 2 blade. Add in the elevator offset and high wingloading, and sometimes things get interesting in a hurry. As already mentioned, build up as much speed on the ground as you can. Did you have any right thrust built into the motor standoffs?

Also...check the rudder to make sure it wasn't trimmed slightly left and no up trim is on the elevator halves. Once the plane is up and flying and you have it trimmed for flight(including elevator)...you will be fine. Further take off attempts should present no issues your not ready for.

91zulu

My Feedback: (2)

That is what you called a snap, due to not enough air speed. You probably was being too cautious and got bit. A slightly off elevator may cause a slow roll, depends on how much off. 4 deg is really not that much to cause a violent left turn. Next go around , start from the end of the runway , get it going at a good clip before lifting off. All you do don`t nurse it down the runway, you have to get it going.

skillet92

Not enough airspeed and not enough rudder. I just madianed mine less than a month ago with a dle 30 that is well broke in. First 3 flights went like this. Taxied lifted off as soon as she would and first two times it banked hard left that I had to just ride each take off out till I got some altitude. Third take off was a disaster in that as soon as I broke ground if leaned hard left and tip stalled. Crashed and burned. I spent the last month rebuilding and fretting over this plane wondering what was wrong. Took it out this last Monday, and with rudder( lots) and speed at takeoff if does great. Hold rudder till well airborne. No issues. 4 flights, four great landings. Mine weights 16+ pounds and it flies great, once the airspeed is up. I am flying with an 18x8 xoar. Good flying plane if you fly her right.

da Rock

Takeoff speed is a winner, but not takeoff acceleration.

The prop is flying from the moment the plane moves on it's own. The rest of the plane isn't flying until each surface has reached it's flying speed. Well, it actually is flying as soon as the wing reaches it's flying speed, but the smaller surfaces usually aren't yet. See what happens? The surfaces that keep the plane flying straight and true don't come online until the prop has gotten on step, and the wing is halfway on step and nothing else has any real "power".

So work the takeoff with some thought. Get it rolling safely, then roll in the power with control. Too fast with the throttle only gives the prop even more head start over the stabilizing surfaces.

da Rock

Interesting idea.

Most always the only thing said about 3 blades is they are less efficient. Sorry to spin off, but let's hope most readers don't come to the conclusion they also are the reason so many flyers dork their planes by firewalling the throttle..... The p-factor of any prop is really a function of the thrust the prop can produce. And it's true that 3-bladers often produce more thrust than 2 bladers (while they happen to be working very slightly less efficiently to be perfectly honest), significantly more thrust.

Any prop that produces more thrust produces more p-factor. I would respectfully suggest that the bottom line on what turned the maiden that's the topic of this thread into a mess was how fast the throttle was pushed. What that caused was the reason, but the cause was from how the throttle was handled.

Most of my warbirds are overpowered according to their designers. Every one of 'em has a 3 blade on it. It's amazing how docile they are on takeoff when the throttle is advanced under control. It's interesting how you can tell when the rudder comes online. It's interesting that it's farther down the runway than most takeoff crashes.

kahloq

Agreed.....I have a good number of Warbirds with 3blade props also. Definitely don't want to firewall the throttle, but you can't limp it down the runsay either and then punch it when start to see your running out of runway.

91zulu

My Feedback: (2)

Rock yours words are of a true warbird pilot. You are quite right about when surfaces are ready to fly. Just to make clear as you stated , the rudder it the first control surface to get online because of the prop wash. The others come on later, some times after the plane is in the air. I am surprised the ESM 190 is that finicky. I thought ESM planes were like CG Tiger 2s in war paint. Well Splais conquer that bird , don`t let it bet you up.

All Day Dan

My Feedback: (5)

splais, good to hear that you did all the right things first. If you have seperate servos on the elevators, make sure the elevators are aligned at the maximum deflection and track well inbetween. Tape an extention rod to them to help. If the servos are not matched, and I do not mean just at neutral and the end points only, they wont track the same from neutral to the end points. Dan.

All Day Dan

My Feedback: (5)

One more point.The longitudinal CG needs to be balanced besides the normal one. You don't want one wing to be heavier than the other. Dan.

Frank Ts Stuff

My Feedback: (130)

Had an ESM P-51A. It was way tail heavy when balanced as per the manual. After the first flight we moved the CG forward over an inch. First flight was a series of snaps (starting with a severe snap to the left), SOME LUCK ;-), a few quick circuits and a landing. Not sure if this is your problem, but this was our experience with the P-51.

Thanks-
Sean


PS - I remember the flight well because Frank said "What the $%?# are you doing?!!" when I took off and I responded "uhhhh..trying not to crash!"

tardster

My Feedback: (2)

splais, I had the same thing happen to me a few weeks ago with my Corsair except I didn't save it before it did all those neat cartwheels lol. Once I got it home and put back together I found out that I had my servos reversed and didn't have enough take off speed. I've been flying for quite awhile now and never really checked to make sure everything was correct, I just seen stuff moving and assumed it was good to go...

Mpizpilot

My Feedback: (45)

If you read the big ESM fw thread, you'll see my maiden was nearly a disaster too. Mine ended up being too tail heavy and it was airborne before I was ready. After adjusting the cg, I found the best way to take this thing off is to get it up on the mains and really let it get up to speed before rotating. These do not fly like a TF arf warbird. They are truly heavy metal type of flying.

straitnickel

Stand in front of your plane 15- 20 feet and study the wings for warping. I have had that happen to me also.

splais

My Feedback: (25)

gee, i really started something. tomorrow will tell, when I try again. I'm now pretty sure it was a combination of things that all combined to increase what should not have been a problem. Too little airspeed on rotation, a somewhat heavy left wing, having to hold in some left rudder for a crooked tailwheel. Don't think the elevator was a factor. Will see in the morning.

neville thomas

My Feedback: (3)

i have a mig 15 that did just same thing if the elevator is not centered and the endpoits dont match they will act like ailevators i experienced this twicw turned out the elevator surface was also off a degree roling to the right make sure all yout end points are the same and make a gage at 45% to check your deflection as to correct the deflection.

skillet92

Well to give you an idea how heavy these planes build, I have a H9 150 mustang that has a dle 35. It came in at 14pounds 14ozs. It has an 80" wing. While my ESM corsair with its 74" wing came in over 19pounds and my fw190 with a 70 inch wing came in over 16 pounds. The h9 flys light and floats in for landings. Now the ESMs fly good also just require more speed at all phases of flight. They do not float, especially the corsair. Lol. And da rock hit it dead on with the comment about not slamming the throttle. I always get mine moving and feed throttle in steadily.

kahloq

Don't know how you got your H9 150 p-51 to weigh just shy of 15 pounds. Ive got that plane with a saito 220 in it and it weighs 18 pounds.