Originally Posted by
Check Airman
PF sets up for an immediate return by joining the downwind. PM fights the fire. What's the complication?
Once second agent is discharged and it's realised that it hasn't worked there's nothing more left to fight the fire with. All that's left is to assess how much time you have what altitude you have reached. From 400ft to second agent discharge should put you above 1000ft. If you assess you have time for a circuit then do so. If required circuit can be done on select speed without any set up. The other option is to do a kind of procedure turn and land downwind with a May Day off course.