"Greg Faris" wrote

Never seen jets do this. I have seen turboprops do it at one airport
(Southhampton UK). I would think airport ops would be worried about
loose tools, articles debris (like ramp agents) getting thrown through
the terminal's picture windows if heavier aircraft start doing this!

Yes...here in the US, the FAA grants permission for "Power-Back"
operations at specific gates and specific aircraft. Pilots
receive special training before they are allowed to conduct
Power-Back operations. I did Power-Back operations in B-727 a/c.

Bob Moore
ATP B-707 B-727
PanAm (retired)