Why such hostility to the original poster? Listen to yourselves. You realise this is a public forum? I'm constantly astonished by the reaction of 'professional pilots' to simple questions. It reminds me of the reaction of the doctors when my family asked about my dying Grandmother 30 years ago 'How dare you question anything we do!'. Sometimes I think aviation is the last 'unreformed' profession. If you don't know... just don't post.