Trailers are typically attached to tractors by a "fifth wheel, " in which a coupling pin on the trailer fits into the center of a large horseshoe-shaped piece of metal.
The devices help pilots avoid "terrain" by coupling global-positioning technology with flight data on speed, altitude and other readings, and a database containing the topography of the planet.
In an ideal world, this coupling should be very loose, so that swapping out a traditional on-premises solution to something more cloud-like would not throw a wrench into a relatively smooth-running process.