First, 18 month olds are a piece of cake compaired to 18 year olds. You may not agree now, but by the time you have cared for both, you will agree[8D]

The airfoil has nothing to do with self corecting. Dihedral is what tends to right the plane back to level flight, at least as far as keeping the wings level with the horizon.

A flat bottom wing will have lift at zero degrees angle of attack. A semi symetrical will have some lift, but more with a sligh angle of attack. A full symetrical has no lift until the angle of attack increases a bit.

I crashed and killed my 4*60. Semi Symetrical wing. I bought a Pheonix fun star as a quick replacement. With my 4*60, I would get the plane centered on the runway and slowly increase speed, keeping on the center line and it would lift off in a shallow climb, like a full size plane untill I pulled a bit of up elevator then it went into a steep climp. The fun star on the other hand would have happly eaten up the full 500 ft of runwan and never lifted off if I handn't cranked in a bunch of up elevator to change the angle of attack. It turns out that the Fun Star sets with about 2 degrees of incidense when on it's wheels, so I had to push down on the spring of the tail wheel to get the angle of attack high enough to get lift. What a susprise. Landing on the other had was a pleasure as the plane keep the low AOT when it touched down. The 4*60 would ballon if the speed was to high when the wheel touched down and the taill dropped..

As pointed out before, the closer you get to a symetrical airfoil, the eaiser it is to fly inverted. Remember that the airfoil doesn't know if it is inverted or upright. A flat bottom wing's lift is to the top, or arched side. If the side is inverted, the lift, is still there, driving the plane down. It takes a high angle of attack to keep a true lift to keep the plane level. As the symetry increases, the lift decreases at zero AOT and the the fully symetrical all lift is due to AOT.

Hug and kiss the kid and help mom get better soon. Just remember your mon and dad went through the same things with you. You are just paying your dues for being raised by your parrents

Don (a four time grand dad who still remembers when he was young)