Early Model 500; three versions?
I was sure that CF-TUP was a 500C. That begs the question; how many different versions are there in the civilian four-blade, Y-Tail series? Leaving out the 500M military version, I reckon there are 3 versions of the pre-D Model 500.
1. The very first was converted from the OH-6A and had the larger window over the rear door, resulting in a smaller rear door than later models (the same size door fitted to the OH-6A but with a larger window). The instrument panel was modified from the T-shape into the vertical-column style panel. Was fitted with the C-18 engine with engine-starting from the left collective. I could be wrong, but I believe this was certified as the Hughes 369A and marketed as the Hughes 500. The first of these was registered N9000F. These were possibly the airframes built for civilian customers from 1968 until sometime in 1970 (at a guess).
2. The next version, which is the one featured in the Canadian photos above, was certified as the Hughes 369HE and was still marketed as the Hughes 500. This version still had the C-18 engine but received the taller rear door with the smaller over-head window. As RVDT states, with a few mid-life upgrades, could then become the Hughes 500C.
3. The last version that I reckon they came up with was certified as the Hughes 369HS and was marketed as the Hughes 500C. C-20 engine and metal tail rotor blades. The ultimate Y-Tail version.
I reckon the difference between the HE and the HS is down to different engines (C-18 versus C-20), but I don't know this for sure. Is this stated or confirmed in the Pilot's Operating Handbook for the type and what else, if anything, differentiated the two?
Just to muddy the waters further, there is (or was) a 500C for sale in Canada with a C-20B engine fitted!
500 Fan.