Many thanks! Robert: I

think this is 'do-able' in 1/1 scale as well. But perhaps not as I've laid it out above ...

The Coulson C295W system uses two retardant tanks listed at 3,500 litre (924 US gallon) each with a total of 6,050 litres (1,600 US gallons) ... (added: perhaps the 6.050L is the usable amount?)

~~and why the 50L increase~~, I don't know.

The C295W has a cabin length of 12.70 m (41' 8"), while the Q200 cabin length is only 9.16 m (30' 1"). That shouldn't be an issue since the C295W cabin fitted with RADS is mainly empty. Weight is a whole 'nother matter, though.

I said in Reply #2430 that my Common Medium Air Tanker would carry two RADS tanks. Not counting tank weight, that 6,050L of fluid alone weighs ~13,350 lbs. But most sources put the Q200 payload at only 8,920 lbs (~1,070 US gallons) ... in other words, closer to a single C295W RADS tank ;P

On the other hand, the Q300 payload is listed as 13,500 lbs/6,124 kg (~1,615 US gallons), which is almost bang on for Coulson's C295W system. My question is: why the big payload difference between the Q200 and Q300? Some models of Q300 have an extra 100 shp per engine. Perhaps the increased payload applies only to those higher-powered models? If so, is 200 shp more really enough to make such a difference in payload?

Q300 cabin size is about the same as the C295. But, obviously, I am missing something here. I can't how adding a total of 400 shp

and 3.43 m (11' 4") of extra fuselage weight results in a 4,580 lbs/2075 kg

increase in payload

Anyone got any theories?