TC,
You state:
"I'd say observation accounts for 10% of our work.
Mostly:
stolen vehicles / failing to stop / robberies / missing persons / all serious land/sea and air crashes / transporting specialists to anywhere in the 10,000 sq mile force area / aerial photography / public order / HEMS / convoy security / searches, etc etc.
Most of this requires us to stay airborne for some considerable time with more than one police officer on board."
Actually, if you look through your list you'll find that the ASU's function in most of your items IS observation. Maybe your ASU has a specific task named "observation", but I was using it in a more general sense. Let's go over your tasks and the ASU's role in them one by one:
stolen vehicles: you go look for them, right? So do we. That's observation. Unless you sling them out as well?
A Lo-jack system can be fitted to the R44 and is, in the LA area, but here nobody has them in their cars, so we don't have one either.
failing to stop: I presume you'd pursue the offenders, transmit your observations to ground units, and have them make any arrests. So do we. Observation again.
robberies: response to calls I was talking about. Observe what's going on, transmit observations to ground units, they make the arrests.
missing persons: we go look for them, eyeball, searchlight and/or FLIR. Observation again.
all serious land/sea and air crashes: I'm guessing these would involve a lot of transporting victims, crews, equipment, etc., and there the police R44 would be almost useless. However, we did find a ship sinking with over 30 people on it, who were saved by other ships once we told them where to go.
aerial photography: we do so too, limited of course to fairly small hand-held cameras or the built-in onboard equipment.
public order: had a prison riot here week and a half ago; we observed for the ground units who had to actually sort it out.
HEMS: R44 almost totally useless here, we don't do it.
convoy security: looking for possible dangers, observation again.
searches: looking for things, people... If that's not observation I don't know what is.
We do our operations with one officer besides the pilot; I agree it would be better if we had two, but it can be done with one, just not as comfortably or well. With our standard crew we have 3 hours endurance plus reserves, I expect similar to yours.