I've seen a couple of doozies over the summer. One was a tango flown by a guy who hadn't been flying a month (and he crashed TWO planes in that month!) - the results were expected; he banked too tight, went into a spiral and BLAP![:@] no more plane. I also saw a guy flying a P38,,,, it looked like he was playing super mario brothers with the sticks. I've never tried to synchronize and get 2 engines running complimentary, but it looks like there's a billion things that can go wrong and put you in the weeds. (I should probably amend this to say "all twin engines", but I haven't seen too many)

The most suprising I've ever seen is the Cub - the fuselage of these planes have a very large cross section that in wind more than 3-5mph will make it crab ALOT. I didn't really think about this one being hard to fly until I started paying attention to a guy one afternoon and, even though the wind wasn't "bad", you could visually observe the plane being blown left and right.

Then there's the Edge 260/540/etc.. + the sukhoi and Yak acrobatic sports planes - in the hands of a novice, these plane's lifespan can be measured with an egg timer. Some people say they aren't hard to fly, but these seem to be the same people with 10 years of experience

Now as for easiest, I'd have to vote in the Parkzone Corsair or T28 - these are so simple even "I" managed a landing!!!

An instructor's nightmare? I'd have to say the guy who shows up for his 1st or 2nd lesson with ANY warbird (aside from Parkzone). The wing loading is so high and there's almost no dihedral to self correct. Couple that with the pure speed most of these have and you're sure to pound it in to a tree, building, car, or ground - unless you're STUPID lucky When I 1st started, before I'd ever flown, I thought I wanted a P40 w/ a 40-46 glow engine. Luckily, a pilot I met told me EXACTLY what would happen and why in very short order and I'm very glad I listened. That guy probably saved me $150+ and the depression of crashing my 1st plane. Thank God for good instructors!!!! Mouth shut, ears turned on, and eyes WIDE open is the sign of a good student. I try to listen and UNDERSTAND everything that is said,,, I also try to have an VERY GOOD pilot on the buddy box with reflexes like a ferret after a Starbucks run No crashes so far, but it's not from lack of trying