Forget the personal statement. Dress nice, relax and be yourself. Boning up on a few FARs will also help. If that is not enough, you probably don't want to work there anyway. I have found that guys and gals that over prepare are usually trying to compensate for something they lack. Pilot review boards are usually made up of pilots. Pilots are pretty down to earth simple people. I would guess that after the pilots on the review board read your personal statement they are likely to look at each other and say "what the f..."??? quickly followed by "next"!