Wasting aircraft range by not having a fuel totaliser

Easy to forget, my car seems to know when I have filled it up.
Simon

I couldn’t fly the Commander without one. The tank gauges are completely unreliable, notoriously so. But the factory totalizer is correct to the pound. Just have to remember to reset it after refueling. It’s on the checklist, but things have managed ton slip by before…

It is, of course, luck that the two were so close

Every 6 months, when I am doing a longish flight, I ‘fill to tops’ at the start and again when I have landed.
This way I can see whether the Engine Monitor does/does not need adjustment.
So far, over quite a few years, with GAMIjectors, my usage has remained very consistent and economical, needing no tweaking of the fuel flow transmitter settings on my JPI Engine Monitor.
This gives me great peace of mind on longish trips.

I guess this thread raises the following questions, like how long the average flight is and how long is too long in your average GA aeroplane? Are IFR flights generally longer than VFR flights?

For myself, a VFR flyer who has flown around Europe, I have come to realise that 2 to 2.5 hrs is the magic number for a leg, and 2 such legs is enough for one day, which will get you right across France. This works nicely with the 100ltr(usable) tank in an aeroclub DR400 which will do conservatively 3hrs 20, and in reality 20minutes more. We have one with a supplimental 50ltr tank and have done a 3.5hr flight in it, but I still try to plan 2hr30min legs. I certainly would not plan a 5 hour flight.

Regards, SD..

I would say that fuel is more critical for IFR since you can land at fewer airports and you need more reserves, and you often also want more reserves due to weather.

On long touring you get exposed to geographical variations of fuel prices, having double range helps, you land every 2h to stretch your legs without refueling

Long range tanks are the best modification for speed & economy out there !

Peter wrote:

Maybe one does longer trips under IFR but in general having a fuel totaliser makes all flying a lot safer.

I have a fuel “integrator” in the JPI engine monitor. It does not tell me how much fuel I have in which tank, but I can do that easily on my own. It just counts from the start starting with “0” and is just summarizing, as it measures actual fuel flow.

At the moment I prepare a fuel table on my kneeboard prior to the flight and enter the amounts I have dipsticked (if it is not full) and how much is used during flight per tank. Having four tanks it is a bit to follow, but still far better than not knowing nuffin’. This summer I have calibrated my system down to 0.1 Gal, and it is such a great relief to know exactly how much fuel I have left in which tank. I do plan every now and then for single legs of ~850nm.

First time I just flew until the engine started to cough and switched tanks, because if not – without knowing how much fuel is left – I would have had to make an intermediate stop. Now I can do that easily without that and arrive happily with 3 hours of fuel, knowing that it is there.

Next planned improvement is to input the values from the JPI instrument into a raspberry PI and to drive a small display where fuel left for the respective tanks (and/or flight time available and so on) is displayed. This is easy calculation, and the JPI does output the data every several seconds. We actually already are running this, but we are only logging the temperatures so far. As the Raspberry also has a GPS receiver, we could also display such things like fuel on target. All this is not difficult, the only thing needed is a digital information of the current fuel flow as an input (which deliver all JPI instruments, for instance) and additionally the fuel on board on takeoff. Regarding the tanks I could either connect it to the tank switch itself, but I think I will just add four buttons which I’d have to push to select the correct tank.