I crashed bigtime yesterday and I am not exactly sure what went wrong. The plane is a Great Planes Big Stik 40 with an OS 55 AX. This was a brand new plane on its third flight. It weighed 5lbs 4.5oz. The balance point was 90mm. with an allowed range of 82-102 mm. Just slightly nose heavy; should be ideal for a beginner. The transmitter is a JR7202. The throws were Aileron +.35 inches - .2 inches; Elevator +0.63 inches -0.46 inches; Rudder +/- 0.75 inches. Exponential was set up at 20% all three. The recommended low rate was Aileron +/-.625; Elevator +/-.75; Rudder +/-1.25. The much lower throw on the Aileron was because I had problems with the aileron being too sensitive on my 1st Big Stik 40. The aileron differential was to cure slow turning difficulties I had with the 1st one. The elevator differential was set up because of too sensitive down elevator on the previous plane. I was trying to set the plane up like a trainor based on my experience with a World Models Sky Raider Mach I.
An instructor flew the plane once and with a few clicks of trim said it was fine. The second flite was mine and I took off very well, the aileron sensitivity was light, very easy to fly, aileron turns were good without rudder, had a little difficulty maintaining altitude; sometimes too high; sometimes too low. On the approach to landing, I decided the plane was too high when abreast of me (About 4 feet AGL ) and I started a go around. A little situational awareness is needed to describe what happened next. We were facing North; the plane was landing West to East. The wind was almost calm - very light. I went from idle to wide open and gave it a little up elevator. The plane very quickly rolled to the right; turned right; flew over our heads to the South. I somehow
managed a half loop to the North and then rolled upright. I then did two touch and go's; one good; one in the dirt but Ok; and
then landed a little hard in the dirt and broke the prop. A Zinger 13X5. Replaced the prop with a MAS 13X6. I was probably
elated because the plane had survived my first flight with it and I had evaded a close call. So I did not try to analyze the close
call - big mistake. Fueled up took a break to relax. Took off. I should mention both take offs were by gradually easing on the throttle and there was a slight turn to the right; easily corrected by even a beginner. Did a few circuits waiting for traffic to clear;
and then started to land. Again was too high and started to go around at about 4 ft. AGL. Again full throttle and a little up elevator. Again a roll to the right and over our heads. Managed to get the plane headed North, but in a knife edge, with the left
wing low and it plowed into the ground. I have firgured out that it was very wrong to go to wide open throttle as half to 75%
would have been adequate. We had just carefully set up the engine before flying and there was no hesitation, whatsoever,
quickly going to full throttle from idle. The plane maintained altitude at 40% throttle. Although not measured; the thrust to weight
ratio was probably over one for both propellers. I need to understand what exactly happened so I can avoid these situations
in the future. I have found a lot of different ways to crash and I am getting discouraged.

Its possible that your getting on the elevator too quickly and perhaps more than what you think you gave it,inducing a tip stall.Sounds like its dipping the wing before the airspeed catches up.On first flights,I take a plane up to a good altitude and check for its stall speed/tendencies.Pull the throttle back and start adding elevator just to see what it does.Some just drop a wing others snap and head for the ground.always good to know before I get into a low altitude situation.

Couple of things..............

Whenever you slam the throttle open on a model that's got little or no airspeed, you can expect the prop to do whatever it feels like doing. The airframe doesn't have the purchase to fight back. The airplane's stabilizing forces are in proportion to their airspeed. When the plane has enough airspeed the engine/prop will have minor effects when slammed WOT or jerked to idle. Turn that around, and the airplane turns around.

Also, when any surface is too sensitive the best solution all round is to reduce it's throws IN THE AIRPLANE.

When a surface feels too sensitive you've got two problems.

The first is that it's too sensitive. Yeah.... It's going to be hard to steer. But everyone knows that. But it is able to give full effect with it's movement without moving much AND your transmitter stick is going to be too "powerful" to be of much use. Exponential does a bit to help. But the best way is simply to match the full throw that is needed from the surface, which is obviously less than the mfg's recommended throws, to the TX stick's movements. Best way to do that is change the servo arm connection point IN on the arm. That way, your servo gets a bit of leverage help. It'll draw less juice and have boosted force from the leverage. No cost, no effort. You get the same result by moving the pushrod connectio OUT on the surface's horn. Whenever you move your throws away from 100% in your TX, you're reducing the accuracy of the stick's control. No need to do that when it takes less time to change a pushrod connection.

But the real killer from a too sensitive control isn't so obvious.
If the surface is too sensitive it tells you something. That surface can be a killer. If it's only taking a very small deflection to be tricky to steer, what do you think it's going to do at full deflection. And if that full deflection comes suddenly? It's going to stall that surface too easily. One aileron stalls, what happens? (The downgoing one at low speed almost always can stall that side in a heartbeat.) The elevator stalls, what happens? None of those things do you want when trying to recover a model that's low and slow and going where it wants to go instead of where you thought it would go.

So when a surface is too sensitive, it's telling you to either reduce it's throws or...... Work on tuning your low rate deflections to give you safe flying deflections. Then use the 100% high rate (you don't want high rates more than 100%) for snappy, tumbling maneuvers. And use a 60% or such low rate for smooth maneuvers like 8s and such. And ailerons at low for takeoffs and landings or whatever works for you and the model.

We got some awesome stuff nowadays. But sometimes it's the killer, not the helper.

Going to wide open throttle isn't bad, just getting there suddenly is.

Deflections that are too sensitive usually have too much throw as well.

Slow flight is a bunch different than flight at cruise or faster.

I want to expand on what 8D3 said. When I fly a maiden flight, be it on my airplane or someone else's, given that it's flying OK and trimmed, I take it high and not only check out it's stall charactaristics, but also what happens at full deflection at slow speed. Full elevator, as already stated, can cause the plane to snap, and I like to ensure that, especially on low rates, the plane won't snap at full elevator. It's a plane saver in a panic situation, because, as you already know, you've got your hands full trying to fly a new plane. If it gets out of shape, the last thing you want to have to remember is to NOT pull full elevator to save it from slamming into the ground.
Full deflection is necessary for a lot of manuvers, hence the need for dual rates.

Just my two cents.

Andy

What he said. If you "wrap" on the throttle and pull up like the is a wall right in front of you, Your in trouble. Many tmes, the plane will roll right over on its back go in. Need to advance the throttle easy and go straight out with maybe a slight climb

Crashed and not exactly sure why.

Most of the time when I Crash it's because of a Lack of Altitude.

Sounds like tip stall and/or torque roll. I take my planes up high on the first couple flights and see what slow flight characteristics are like, that way I can get a feel for when it will stall or snap out on me. Then when I'm landing, I know how slow I can go before I get into trouble.

It absolutely sounds like a tip stall. Thats why I always train my students to make the decision to go around early. Second, once the decision to go around is made, add the throttle and gain airspeed before trying to pull up. Its just like take off, only your wheels are not on the ground. Many new flyers wait to long to decide to fly around, and then they think they can just yank the plane up in the air. A Stik is going to try to snap on you, particularly if you have low air speed.

Rebuild and fly again.

Brad

I'm just new here myself,but I'm flying a big stik .60 with a .90 engine on it and it flys awesome. I'm only running a 13x6 prop. I would believe a 13x6 prop on a .40 size plane even with a .55 engine seems very large. It would definely make sense as most of you guys are saying that slamming the throttle wide open at such a low speed could be a cause for a big problem. That big of a prop on such a small plane....I could see the motor spinning the plane before the prop,but wouldnt the plane tend to turn to the left instead of right?

Actually,I wasnt sure so I just went out to check and its only a 12x7 I have on there. My 13x6 is my spare. And I think its big!

Hi!
Very simple! Inexperience!!!

I initially set it up for minimum mechanical throw. In close at the servo and way out at the horn. The elevator and the rudder did not
have enough travel so I ended up moving the elevator one hole in at the horn and two holes in at the rudder horn. There are four horn holes total. The d/r low rates were 70% aileron; 100% elevator; 102% rudder. hi rates were max 125% all three. The only thing I would change if I rebuild it would be to increase the d/r low rate for the aileron to say 80% as it was a little too easy for a newby and the roll rate was very sloooooooow. About 180 degrees in 2 seconds. On takeoff does torque steer go right or left?
It must have tip stalled because it happened so fast. I would have thought that differential aileron travel would have reduced tip
stall. I have enough repairable pieces to put together another big stik 40 but my heart is just not in it. I got a Sig Kadet Senior
that arrived Thursday and I think I will put that together with an OS 55 AX. To practice slow flight will require going back to a buddy
box because I don't have the skills to recover from a spin. I have tip stalled a Cessna 150, 100% scale, with 40 degree flaps at 6000 AGL and it scared the H or S out of me. Thanks for all the responses in just a few hours. You guys are greeeeeaaat. On a go around less than full throttle, hold elevator and an earlier decision. The fast decision is the hard part because it seems things are happening at the plane a lot faster than the brain is working.

slow flight+rapid throttle advance=snap roll. I teach to use full throttle on go arounds..one of the useless things in aviation is airspeed you don't have...Perhaps your next airplane should be a tiger, 4*, Or sky raider..
Good Luck

Differential helps yaw the airplane into the roll. Very often, when a wing is close to stall any downgoing ailerons pushes the airfoil past the stall angle of attack. Remember, the TE of the aileron is the TE of the airfoil. And if it goes down, the AOA changes with the movement of that aileron. As fast as that aileron is moved. Which is faster and farther than the wing on that side can probably handle without stalling.

Using aileron to turn when low and slow is not the safe way to fly.

You probably do. Take the airplane up two mistakes high. Do all the slow flight straight upwind. Most of the stalls you'll see will be relatively slow. Remember the fullscale lessons.


You need to back off trying to come up with a list of things to do when whatever happens happens. "On a go around...... whatever..... you should....." On a go around with any throttle position you do whatever needs to be done with the elevator to fly the airplane along the path you want it to fly. And you do with the throttle whatever needs to be done to make the airplane go along the path you want it to fly. Same with rudder. It's ok to keep in mind the idea that ailerons aren't the best choice when low and slow, but that's not really a recipe.

A go around can be full throttle or less. Don't setup some rigid recipe for go arounds. You're definitely going to need more throttle, but heck, whatever more is enough to give the airplane a comfortable climb will be good.

You need to forget the list of recipes. Learn to fly the airplane where you want it to go. If the amount of elevator isn't doing it, if the throttle isn't enough, give them what is needed.

It's a fun hobby. And not everyone gets to do it. We're lucky ain't we.

BTW, differential aileron isn't one of those things that's set from a formula.

Truth is, if the upgoing aileron (the one that's supposed to cause increased drag) goes too far too fast...............

BTW, differential is usually only of real value on a cambered wing. It sorta screws up airplanes with symmetrical airfoils. That airplane have a semisymmetrical wing?

You made every possible mistake to cause this problem. From a slow speed and probably nose high for landing you slammed full power which caused torqueing and turning. Then you raised the elevator instead of just maintaining altitude and letting speed build and keeping the wings level with the rudder. This probably stalled the plane or snap-rolled it.
3 things are wanted on a go-around. Maintain altitude, gain airspeed, gain altitude in that order. THEN turn off runway heading. Deviate from runway heading only to avoid obstacles (people).

If you have solo'ed a trainer than you got the skills to practice slow flight.Like daRock said,get to a comfortable altitude and try different situations.Stiks are great planes,forgiving enough to recover from stalls(at altitude) and will handle aerobatics well.more you fly a particular plane the more its habits will be ingrained into you.Youll know if your too high,too fast,too slow,etc earlier and then youll avoid the situations where you feel the need to gun and jerk the plane into the air.

I'd suggest jumping back into a Sky Raider Mk I for a while. It's a very capable plane and you can still learn a lot from it. It will handle the basic pattern routine with no problem. The Mk I is capable of any aerobatic maneuver that your Big Stick is capable of doing, and its a plane you are familiar with.

As was suggested before, what ever plane you fly, take it up high and work on basic stalls straight ahead. Stalls a very simple to do and you should have been shown not only how to stall and recover, but also how to get out of a spin in your basic training. I consider spin training a mandatory requirement before I let a student off the trainer chord - if you can't enter and exit a spin, it'll rear its ugly head and bit you before you know it. I've seen many very experience pilots of advanced pattern contest caliber get lax on their approach, stall and spin their pattern planes in, so it can happen to the best. If your not comfortable in working on stalls/spins by your self, then by all means go back on the buddy box for a flight or two with an instructor and learn how to get in and out of a spin. After a few times you'll come to love doing 3, 4, 5, or even 10 turn spins and come out on exactly the same heading you entered it.

And follow Bruce's go-around technique: Add power, maintain heading and altitude until airspeed is built up, then start turning. Bank at a low airspeed just leads to an accelerated stall and the classic stall/spin/crash & burn maneuver. [:'(][&o]

Hogflyer

edit: On any plane I haven't flown before, be it a new one or a students - I like to do at least a couple of stalls and some slow flight to make sure I don't see any nasty surprises when I'm least expecting it. I also like to practice slow flight right on the edge of a stall, even to the point of bobbing into a stall and recovering I'm that close to the edge. I also practice snap rolls and spins on most of my flights unless I'm just shooting landings or instructing. With experience you'll learn to feel when a plane is on the edge of a stall and avoid actually entering one.

Here is a list of planes I have flown so far and are listed in order easiest to hardest to fly.
Great Planes Big Stick 40 easiest landing of this list of planes.
Hangar 9 Alpha 40 very good - have had some problems on landing
World Models Sky Raider Mach I I found and have been told by others that this plane is a little hard to land
Mini Ultra Stick Totally beyond me from takeoff to flying around to landing.

Two Big Stik 40's, the Alpha 40 and the Sky Raider have all been destroyed.
I am moving on to a Sig Kadet Senior which according to the 300 references I have read should be the easiest trainer
to fly. I think I understand what happened. Use of the elevator increased the angle of attack which caused the tip stall. At that point the plane was out of control but continuing to stay in the air on engine power alone. The first time I was able to save it; the second time it crashed. I have to have a preprogrammed set of instructions to follow because it may take me 2 or 3 seconds to react
to a unfamiliar condition. Thanks to all of you for the help. I am pretty sure I will not make that mistake again. What concerns
me is how many different ways there are to crash. I have not repeated any yet.

People think up new ways of crashing everyday.The important thing is that you slowed down and took time to figure out some things and are willing to invest time trying to learn better ways.I bet you'll make it as a r/c pilot yet.

Hmmm... how many ways can you crash... here's some general categories I've seen, I'm sure you can add to the list!

1) Dumb-thumbing it into the ground - pilot looses perspective and pulls up instead of down, etc.
2) Unexpected aerodynamics - pilot causes an unintended stall or snap, and can't recover in time.
3) Unexpected obstacles - pilot's depth perception tells him he's cleared the trees, but no [:@] .
4) Random equipment failure - mechanical or electronics failures in flight causing loss of control.
5) Stressed equipment failure - pilot pushes airframe or servos harder than intended causing failure.
6) Getting shot down - two pilots switch on a TX of the same channel, and one of them is flying.

There are 4673 ways to crash & I have experienced them all except 1---------The 1 where it was my fault-------It's always someone elses fault or equipment failure or the wind's fault or the airplanes fault or the suns fault or the kids fault or, There are 4672 ways to crash a plane that aren't your fault.

And you will never have a complete set of preprogrammed instructions for all the different situations you're going to see.

You need to focus on flying the airplane where you want it to go.

Forget about identifying the situation and then what the airplane is doing in that specific situation and then trying to remember what the checklist says you should do in that situation.

If you see the airplane's nose coming up and it shouldn't be coming up, you need to move the sticks whatever way keeps that nose from coming up. And that happens if YOU are flying the airplane upwind, downwind, on approach, in a loop, in a turn or taking off or landing.

You don't take 2 or 3 seconds to react to the nose coming up. You simply put it back down where it should be, where you wanted it to be.
Learn to react to the airplane. And that won't take 2 or 3 seconds. Trying to remember the checklist's instructions for the specific situation will.

How long did it take you to see that the airplane's nose was too high on those takeoffs and go rounds? Did it matter that the airplane was taking off and it's nose was too high, or just that the nose was coming up and it shouldn't have been? Same deal whenever the nose is coming up and you don't want it to. Fly the airplane, not a checklist.