A lot of terms on aircraft go back to coaching/sailing/ships. (Keel, Water Line, Frames, Cockpit, Port, Starboard, Forward, Aft, Captain, First Officer for example). Jump Seats were fold down seats on early automobiles. Jump Seats on aircraft are fold down seats (Cabin Crew Jump Seats in the Cabin and flight deck seats as in the A300, B737, BAC1-11) The other seats in the Flight Deck which are fixed and more substantial in design although defined by some as being Jump Seats are actually defined in manuals as Observers Seats (normally 1st, 2nd etc). Other seats in the Flight Deck that some folks thought were Jump Seats were for Crew positions that weren't used all the time (Radio Operator and Navigator on the Britannia operating short haul on IT flights for example).
It would be interesting to see exactly how many terms that may be thought to have originated with aircraft actually came from other areas.
Yes, I know, I should get out more often.
Temps.