groundpounder2

A friend and I are learning to fly on a Hobbico Superstar MKII RTF. The plane flies quite nicely once it's in the air. Takeoffs are a little hairy. The plane rolls nice and straight down the runway but just below takeoff speed starts to go to the right and after takeoff continues to the right until full flying speed is reached. Once it's up and flying the trim is very good. It will fly hands off for several seconds.
Most of the time this is not a big deal but last week my friend was taking it off and didn't correct in time to keep it out of the chain link fence. Naturally we would like to avoid this in the future.
Since it rolls straight at slow speed and flies straight at high speed I figure the rudder and ailerons must be fighting each other somehow, buth I'm not sure how to go about correcting that.
Thanks for anything that will point us in the right direction.

nilo

If the plane just don't go straight when on the ground, that's probably because the front wheel gear in not positioned correctly, aligned to the rudder. If you have a tail wheel direct connect to the rudder, also check its alighment when the rudder is straigh.
That's what I would look at first.

Nilo

Crash90

My Feedback: (17)

A trainer should fly hands off for more than just several seconds. Which way does it drop after those few seconds?

Easiest way I know to initially trim the rudder is go vertical. If it doesnt go straight up then adjust the rudder accordingly. Once thats fixed you can trim your ailerons.

MinnFlyer

My Feedback: (4)

Is this a roll to the right, or a yaw?

Stick Jammer

groundpounder2,
By your description, I would say it's most likely a gear alignment problem. If it were a control surface problem it wouldn't straighten out at high speed to fly hands off. Try rolling the plane on a hard level surface (engine off) and see if goes straight.

Rodney

As stated above, most likely a gear problem. Is one wheel draging or cocked at an angle? Is the nose gear lined up when the rudder is at center? Normally, a plane will require a little right rudder to overcome engine torque until adequate speed is built up, especially on tail draggers.

Ed_Moorman

My Feedback: (1)

I don't knopw if this is your friend's problem or not, but I have found that many beginning fliers tend to freeze their left hand on take off. If he had to use some right rudder on initial take off roll, and forgot to release it, the plane could go right. After take off, the rudder will tend to over power anything except a large aileron input. Try it in the air. Put in a lot of rudder and hold it, then level the wings with aileron. More than likely, you'll find it takes a lot of aileron.

Here's another thing to check. Look at your elevator. If you are flying at full, or nearly full, power, you may have down elevator trimmed in. If this is the case, the plane could be raising the tail before lift off. It is very common for a beginner to roll down the runway much too long before lifting off. I see people all the time with one main gear off the ground. At high speed, the plane has to fly slightly nose down to keep from climbing. On take off, the plane can't get the nose down because of the runway so it raises the tail. This can put extra weight on the nose gear causing it to veer one way or the other depending on gear angles. If this is the case, you need to hold enough up elevator at the start of take off roll to neutralize the elevator. I have my students hold 1/3 to 1/2 up elevator and when the plane gets to lift off speed it takes off by itself.

Hossfly

RIGHT on. All the advice previously given should be adhered and checked on.

However one little item that I have noticed for the past couple years is that a number of the newer trainers have a built-in "right-rudder" as the vertical stab is offset for that reason just as many of the WW II fighters were.
The offset VS will be applying the "right-rudder" to offset the normal left-turn during TO. Normally Ed had it figured for a straight VS, but the newer offset VSs do the work for the newer pilots, and at lift-off become very much controlling as Ed stated.
Without instant correction, an unexpected right turn can catch one by surprise and ingrained inputs become confused. [X(]

Having to rudder left, well now THET jus' ain't natural, and those guys transitioning to the Griffon Spits found that out, big time.

3DFanatic

My Feedback: (5)

ANY plane should fly itself for more then a few seconds (provided it's straight and level when you stop flying).