Peter wrote:
And I thought I was tight, landing at LDSP with 45 litres – the lowest I have ever done. But there are normally loads of alternates down the Adriatic
Well, your fuel flow is higher than mine. Normal Cruise is at 37 lph and eco cruise at 31 lph. Still, 45 liters would be about what to tanks dry? 1 hr? With 30 liters, I could have gone back to Altenrhein if they had made me, but as I said, I asked them before passing Altenrhein.
Yes, a totalizer is very useful indeed.
It’s a question of common sense too. Going with a planning which takes close to the max range into an area which is full of runways to land on is much less of an issue than going someplace where you have 100 NM to the next suitable diversion port. Yet it does also not make sense to go over the top and plan fixed amounts which cut your range in half.
High altitude (FL160) cruise 32 L/hr.
Mid (FL100) cruise 40L/hr
Low level (say 3000ft) cruise 43L/hr
All for 140kt TAS.
Peter wrote:
unless it isn’t because you have tons of fuel and a big enough bottle to pee into
I’ll never take off anymore without that:
TravelJohn
I had my kind of experience before 
Also recommended by Prince Harry
A pilot friend told me a story about a longer flight in a C172 where he simply had to go and pee. Having no “Travel John” he wisely thought that the plastic bag the vests are stored in could be a smart idea. Unfortunately the bag he used had tiny holes in it. Yikes.
I know a guy who peed into a thermos flask
I just take a couple water bottles. tiny opening (:)) which never had to use, but it’s always there.
I also tell the passengers that the little window you can open is to release the pee bottle in case you need it. Usually makes them laugh (useful when some are tense, 1st time flying small plane)
