the idea
the captain's voice is the calmest voice most people ever hear. it tells you the altitude, the weather at your destination and when you'll be at the gate, and it never changes. this ladder keeps that voice and takes the plane away from under it.
the turn
rule 2 puts the plane in the ground. most people write that one straight, and it comes out grave: listen carefully, god bless you all. rule 3 then locks the register to routine, and the grave version fails. from there every rung adds worse news that has to arrive in the same tone.
the banned list takes out the honest words. without landing, crash, emergency, brace, impact or problem, the captain has to reach for the airline's own vocabulary, and that's where the jokes live: an early arrival, a development with both engines, putting down in open country.
rule 6 is the sightseeing announcement. those of you on the left will see something out of the window. by now there is only one thing to look at.
the last rule asks for the arrival time, which every announcement gives, and sets it under five minutes. said flat, with cabin crew asked to be seated, that number is the whole ladder.
the words
the meter for rule 2 wants to be told where the plane will end up. a draft that had the steep descent, the missing engine and the minutes left, but never said it wouldn't make an airport, scored 0.13 on it. so say the field.
the word cap sits at 65. the ordinary announcement you wrote at rule 1 was about 50 words, and the finished one should be too. nothing in it is new except what it describes.