Quite simple or am I missing something here?
Many fuel gauges are stuck, or they stick in certain positions.
Often the transmitting mechanism (usually a crude potentiometer, working off a float) is intermittent.
Obviously you don't need a fuel totalizer if you're doing one-hour trips
That's true if you always fill up and always do 1hr trips.
But the typical UK PPL training scenario is that the school works off a "tech log" e.g.
10/1/2011 Filled up full - endurance 3 hrs
11/1/2011 Flown for 1hr 40 mins - endurance is now 1hr 20 mins
12/1/2011 Flown for 50 mins - endurance is now 30 mins
12/1/2011 55 litres put in (some calc...) endurance is now 1hr 30 mins
12/1/2011 Flown for 30mins (
but actually flown for 50 mins) - endurance is now 40 mins but is recorded as 1hr
13/1/2011 Flown for 1hr -
OOPS
The choice of the final date is intentional
When I started my PPL training, I knew s0d all about flying but I was horrified by this procedure, with the obvious potential for cumulative errors and omissions, and I think the same of it now. Anybody with a technical / engineering education or background would think the same of it.
The basic issue is that poorly equipped spamcans don't have much useful range to start with and they tend to get operated either by shrewd people (who don't go anywhere near the limit) or by less than shrewd people (who rely on a lot of luck).
I know I bang on about the TB20 but on that you can fill up at Lydd and fly to Benbecula, with Lydd as your alternate, and (in zero wind) you will still have enough fuel to fly on to roughly Biarritz.