at our field there is a 20 min rule if there is a few guys waiting you must yield and allow the next in line to fly his time. if there is a available slot in the rotation you are allowed to take your plane up if the net in line yields to you, most days there is not a crowd but on sundays there can be a few guys in line .civility is the key its in our club rules so there is not any question as to the proper etiquette its spelled out for every one to read for themselvs fortunitly there are real gentlmen at our club and I have never seen a conflict myself