The co-pilot of this passenger aircraft is seen to open the cockpit side-window, pick something out from the window housing, show it to his captain before throwing it out the window. Someone has suggested it could've been a block of ice, but a pilot who I reached out to who flies this aircraft type said this is unlikely and a very unusual occurance, "we would very rarely open the window with the engines running since it's very very noisy and if you throw something out, there is always a risk it gets sucked into the engine...I find this very very strange". Whatever the object is, it appears to shatter into several pieces upon hitting the ground. Another issue with the copilot throwing something onto the taxiway is it creates 'Foreign Object Debris' (FOD), something airports and airlines do all they can to reduce and remove since it creates a risk of engine ingestion and airframe damage.

"foreign object damage (FOD), is any particle or substance, alien to an aircraft or system, which could potentially cause damage...External FOD hazards include bird strikes, hail, ice, sandstorms, ash-clouds or objects left on the runway. "

Video filmed at Split Airport, Croatia on 3rd October 2021.