It still was a screw up, letting it run for the full 4 minutes.... There was no way to judge how many cubic feet of it was discharged when its blowing all over the tarmac, so it was a waste of time....
if you meant in them tests there were none in the hangar and if you mean when the system's used for real the whole idea is that the foam goes on the plane to put out the fire that's proberly engulfing it