A Walter Kline sent a letter to the editor of USA today. In it, he stated that an airline pilot who had written a previous letter did not know her aircraft has an outflow valve. He based this conclusion on a statement by her explaining how a bullet hole in the pressure vessel could cause a rapid decompression. Since there is already an outflow valve, a bullet hole would be "inconsequential", states Mr. Kline. He then stated the biggest safety factor is an airline pilot who doesn't know the systems of the aircraft being flown. UNbelievable. Reminds me of the time a private pilot came to the cockpit after a flight. He proceeded with a list of "squawks" he had discovered during flight...yaw damp inop (nope, that's turbulence), the exhaust stack of the right engine was loose (nope, that's how the engineers keep it from breaking off), and best of all, he noticed a vibration (no SH!T...it's a Brasilia for pete's sake!). I hope Mr. Kline can assist other flight crews in the future should they need his expertise. How embarrassing (sp?) to be so ignorant that you don't know you're ignorant (hey, that's ME!). I got a good laugh out of it (as well as sending a letter of my own to the editor).