well to my knowledge there no radial droms on fire work. the accident was a modified turbine drom. the radial drom is actually a terrific aeroplane on fires, a little slower than a turbine to and from the zone but over the drop zone it is more precise the lord give with one hand a take with the other.
if you trend any aircraft it will be as reliable as any other aircraft it is a myth that turbines are more reliable. rfs think that piston engine aircraft arnt reliable can you see a pattern forming yet ?