HI SSCBD, fair comment but my experience has been thats its awkward based on a set up of:
container or ground or platform near height to wing tank
rotary pump inserted into container and may not have a firm fit ie it just "sits" in the container filler hole.
hose then is inerted into wing filler hole or into Mr Funnel and held some how ie with your hand,
other hand then has to rotate pump handle
have to lean over tank hole to watch for overfilling/ spillage.
So yes a rotary hand pump is simple and electricity free, but requires coordination and fine movements!!
Matt, after 30 years of filling high wing aircraft in the bush you get a bit smart on doing things. Not being rude but lifting 20 litre drum up on a high wing where you need a ladder or box etc. it not pleasant or feasible either on remote strips or away trips.
I have watched people fall over, hurt their backs trying to lift 20 litres or dropping drums and spilling fuel or the drum slides down the back and off the wing spilling fuel everywhere
1. So I have a rotary pump that pushes a half litre of fuel per 360 degree rotation. It weight 2.5 ish to 3 kg, never put it in a scale but around that weight, by the non scientific method of using the 3 litre milk hand weight comparison.
2. I have cut to length the excess filler tube and put a "SMALL METAL S HOOK" through the end of the hose that is then inserted into the wing filler hole and hooks INTO internal lip, so the hose it wont fall out and its fit and forget while refueling.
3. I have cut the bottom end tube off and slipped a (petrol proof) rubber tube to fit 20 litre drum in length. This takes the excess metal tube bulk and weight out of the pump also.
4. I have two free hands now just to hold the pump in the drum and wind away. - so easy.
5. As I know how much fuel I need after dipping the tanks BEFORE fueling I know how much I need and can count the turns if needed - so no overflow or spillage.
Mark - Don't take this a being rude, - but it works so well and is so simple why would I change the system. The little - S- hook on the filler end of the hose is the true answer to holding the tube filling over wing aircraft HANDS FREE and wont fall out.