Since tracks are having issues here is how to replicate it:
how to reproduce
Guy A: Spawns at airfield, sits and waits
Guy B: Spawns on ship, takes off, and fly's to airfield that Guy A is at. Guy B lands at said airfield.
Guy A: Watches Guy B bounce up and down (in time and intensity with the ship he took off from, pitch and roll).
something to note: Once you have landed / taken off from the boat, you will bounce up and down even if you jump in a plane that spawns at an airfield. you need to leave the server and reconnect to stop this phenomenon. Also, others that have spawned on a pawed or have landed at one then go to an airfield may not see anyone else bouncing who may be bouncing to an airfield spawned jet.