(shortened)
1. Spare capacity = flexibility.
2. Fuel load is the easiest to adjust
3. 20 stone Pilots or Obs make a mockery of flexibility.
4. NPAS needs visitors to ASUs to spread the message.
5. Standardising aircraft types/specs
6. Police equipment & upgrades
Clearly each unit will have its own idiocyncrocies, and I'm not sure whether zobra is being generic or basing the post on experience, however as I see 1-4 (based on my experience);
1.
Spare capacity = Operational Limitation
2.
Fuel Load = Operational Availability
3.
20 stone Pilots or Obs don't exist
4.
NPAS does get visitors
1. When the times I've been called to carry an 'unannounced' operational pax straight from base can be counted on no fingers, yet the times I have been on a 'routine task that' turns into a distant and/or prolonged task etc. can be counted on a centipede or two, I'd rather have that extra 30 mins fuel already on board thanks!
2. Sitting on the dispersal with 30 minutes less fuel than I can take, generally means that in 90 minutes time I have to; leave the job earlier, not do the jobs that always crop up on the way back in and limits my circle of ops by a 30 mile radius etc. If an operational passenger was ever to have to board at base (see 1.) and the fuel load was too high, one of the observers can always be initially left behind. As far as subsequent crews are concerned,
my zfw is probably of the heavier, so as it turns out, I tend to leave the ac below the max fuel for the next crew configuration anyway. Besides, come the latter flight(s) of the shift, the fuel uplift is adjusted, if necessary, to allow for any special loadings for the next crew, such as a visitor or training. Surely the easiest thing to adjust, is the thing that you don't have to adjust just before going out
3. We are still waiting for evidence of this
mythical 20 stone observer.
4. I think you'll find that most if not all units run a visitor scheme to allow for just that process to take place.
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If I may finish on a point from 5.
it would seem sensible, in the light of the above discussion, to at least ensure all 135s were able to maximise their endurance by upgrading to 2910kgs.
Based on zobras previous comments, what's the point of upgrading to 2910kgs to maximise endurance if you're keeping that spare capacity (in the form of endurance), just incase someone turns up to fly, which in my experience, they don't!