We're heading to Disney for the first time next week or so and I was wondering about the protocol about having my 4 year old see the flight deck. He's obviously flown with me numerous times and loves airplanes, but has never been in a jet before. Is there some secret handshake that would let him see the front at least for a minute? I imagine this varies wildly between airlines, captains and how busy things are, so my expectations on accomplishing this are very low. Is there some proper protocol in regards to this request? The airline is Delta, if it matters.