ORIGINAL: JohnW

Flat square trailing edge - While I have no scientific test data and only empirical evidence, it is fairly well accepted in the circles of pattern pilots I've been known to hang out with, that blunt (squared) and often thick trailing edges help tracking. Razor sharp trailing edges seem to cause tracking issues. Some pilots have even been known to apply triangle stock to the TE of control surfaces to make them really thick. With a thick blunt TE, it seems the control surface is being stabilized or dampened, which would maybe imply less chance for flutter.