I this question Why would a fighter drop fuel into a drone? it was essentially asked if the SU-27 has the capability to deliberately dump fuel in a controlled manner. My question is if other current military aircraft (of any country) has the ability to do a controlled fuel dump, and if so, under what operational situations would this be considered a valid and useful military tactic?
Really the only time that’s used is just to reduce the weight of the aircraft in order to recover, i.e. reduce the weight to at or below the maximum landing weight of the airplane in order to land safely, just as is done on jetliners or other aircraft for normal or emergency operations. Similar results can also be achieved by jettisoning ordnance from the aircraft, including external fuel tanks, but this procedure would be frowned upon during peacetime operations, and especially over populated areas. It’s simply easier to reduce weight by dumping excess fuel.
There is no other useful or military tactic associated with dumping fuel like that. What you saw on that video was not some standard military tactic or interception procedure. It was two Russian pilots hotdogging (and they have a VERY bad reputation for doing this during routine intercepts over international waters) and paid a high price for it. I don’t know what the extent of damage to the SU-27 that collided with the drone was, but the pilot was probably darn lucky that he didn’t get killed in that circus stunt.