And here is original script that made by Pica.
;
;Created by Pica
;
;Modified by Loc-Dog, it now works on a timer!
;
;area of flak around target
;random height of flak
;target aircraft
;game logic name
;ammo to use
;timer
;
;example
;[150,10,blackhawk,log1,"shell73",10] exec "flak.sqs"
_area = _this select 0
_height = _this select 1
_target = _this select 2
_logic = _this select 3
_ord = _this select 4
_timeleft = _this select 5
#loop
_timeleft = _timeleft - 1
_where = getpos _target
_logic setpos [(_where select 0) - random _area + random _area, (_where select 1) - random _area + random _area, (_where select 2) + random _height +10]
_bomb = _ord camcreate getpos _logic
_bomb = _ord camcreate getpos _logic
~random 2.5
;you can change the condition below the end
? (alive _target) && (_timeleft > 0) : goto "loop"
exit