Think about the following situation. You fill up both wing tanks, depart and during the flight the left fuel gauge frequently shows wrong readings. Sometimes it shows what might be the right amount of fuel in the tank, sometimes it goes completely to empty, sometimes it just bounces up and down. Then you have the fuel totalizer, which is working properly. You also switch from one tank to the other every 30 minutes.
In a situation like that it is probably a good idea to keep a log of switching fuel tanks. At the very least it helps with your own confidence that you are not emptying one tank before the other.
Would you consider the faulty left fuel gauge or the sensor in the tank a safety issue?
Would you continue for a long time without fixing the gauge/sensor because you have the totalizer and keep a log of switching tanks?
Would you try to always depart with full tanks?
What is your strategy as owner pilot to deal with such an issue?
Would you consider the faulty left fuel gauge or the sensor in the tank a safety issue?
If it’s your SR22, get it fixed. The Cirrus has very accurate fuel sensors.
Would you continue for a long time without fixing the gauge/sensor because you have the totalizer and keep a log of switching tanks?
Of course because the majority of the GA fleet does not have good fuel tank sensors. There is basically nothing you can do on a Cessna, Piper, etc. from the 70s.
Would you try to always depart with full tanks?
Yes, I have never departed with less than full tanks because it was required by the W&B and I would not want to own an aircraft where I have to do this. Too much place for errors. I’d rather go 50kg over gross than not filling the tanks.
What is your strategy as owner pilot to deal with such an issue?
I know my power settings, I know my fuel burn. I would not go on trips where that rule of thumb calculation is not accurate enough. However, I also wouldn’t depart on Peter’s infamous 7h flights just because I would not enjoy sitting in the cockpit for so long. Still, I use my very accurate fuel totalizer and compare the results with the bowser pump every time I refuel. It’s just reassurance.
I fly an SR22 with the older unreliable gauges and rely on the totaliser which is fine imo (unless you have a fuel leak)
I tend to switch tanks based on fuel used rather than time as that gives more useful information on how much fuel you have left. There’s an iPhone app called ‘tank2’ which works out the changes so you land with perfectly balanced tanks. :)
Personally, I woudln’t fly for very long, in an aircraft where I could be looking at a fuel guage showing less fuel than needed for the rest of the flight, and be left assuming that there was in fact enough fuel, based on the totaliser.
It’s all too easy to have a fuel leak, and then to ignore it because you deem the guage to be unreliable.
I’ve come across two cases of fuel leaks; both due to stuck fuel fuel drains, but they only showed up in flight with the airflow moving over the fuel drain.
As achim says: If it’s your aircraft, get it fixed soon, and in the mean time, if there isn’t enough fuel in the other tank, then land.
There is basically nothing you can do on a Cessna, Piper, etc. from the 70s.
I fly a Piper from the 70’s. While they might not be super accurate, they are consistent, and predictable if you fly it regularly. If they showed me 0 fuel, and I expected 1/2 tanks, I’d be landing pretty rapidly, unless there was enough fuel in the other tank.
If they showed me 0 fuel, and I expected 1/2 tanks, I’d be landing pretty rapidly, unless there was enough fuel in the other tank.
The only certification requirement for 1970s fuel gauges was that they show 0 when the tank is empty…
… and be repairable by anyone with or even without a basic soldering iron.
The only certification requirement for 1970s fuel gauges was that they show 0 when the tank is empty…
Indeed, but that isn’t what happens in practice. Some stages they down faster than the fuel is being used up, and some stages slower. But if they show empty, then it’s pretty certain that the tank is empty….at least on the one I fly.
In my club 172S the right fuel gauge is showing essentially full all the time – and occasionally the indicator is flagged as invalid (this is on a G1000-equipped aircraft). We’ve been asking our maintenance company to fix this for years, but they have never been able to figure out the problem.
Fortunately the fuel totaliser in the G1000 is very accurate. Just as long as you don’t get a leak somewhere…
@Airborne Again: I believe your aircraft is not airworthy.
