Model_Aviator

Dear All,

Can anyone explain that weired phenomena? I had an electric Cessna-Sky Line from The World Model (electric) 41" wing span. I used an Art Tech motor and the stock propeller that came with the Cessna.

the CG is little towards the nose. In the first flight I did a loop. in the top of the loop it just stalled and entered in to a spin. As I wasnt too high (which is a mistake) it crashed badly on its nose. Not worth fixing.

I bought a new kit and fitted the same motor and servos on it. on the same park the hobby store owner (which is very experienced flyer and is my friend) took it off for a test flight as it took off he was just picking up some speed, as he was climbing up all of a sudden it went in to a spin roll again (no he wasnt doing any looping / aerobatic) then crashed.

what is this!! any explaination. Cessnas are very stable and even on the box it says "Skill Level: Bigginer to Intermediate"

Even my experienced friend didnt know what was wrong. He got very upset for crashing my new plane.

Any explaination? is it the set up? are we using the wrong motor? I'm confused.


Cheers,
Model_Aviator

Lnewqban

Find some general explanations here:

http://www.rcuniverse.com/forum/m_8947745/tm.htm

Sorry about your crashes[&o]

Model_Aviator

Thanks! the link has lots of good technical info. I have found the source of problem. It is so simple.

the problem was in the CG. Yes. The battery location was too high. it should be placed below at the bottom of that Cessna. In fact it has a little small battery door at the bottom side of it  funny we didnt bother to place the battery in its correct place at first.

the model flys great now without making that stange stall spin, but I was flying last week in a huge park lot and I hit the light column (crashed)

lucky all servos and receiver are OK (but not the motor) I will take those servos and fit them on probably another Cessna kit (this would be my third Cessna) I hope it last with no crashes this time/


Enjoy flying,
Model_Aviator