[Chasnaisflyer]

I was out today and dipped the tanks in my '172 before departing. Enough for there and back with something to spare.
On departure for the return leg at the hold, running through the checks. I got to the "fuel on and sufficient" and even by the standards of the very unreliable Cessna fuel gauges it looked a bit on the empty side. It was starting to rain and my passengers were keen to get home but I was not keen on being the subject of one of those accident stories in Flyer ( and others)

So I abandoned the departure and made a check. One of the tanks was EMPTY. The other had enough in it to get home. It made me nervous though. What if one of those tanks was not feeding?I parted with money to fill up the tanks and ran up for a while switching tanks. All was well. As was the eventual flight home.
I think perhaps the aircraft was parked on a slope and I had the tank selector to both.

Anyway I will be checking again and keeping an eye on it, but post this as a lesson to myself and maybe of help to others.

[MichaelP]

Likewise, in a Cessna 152 with long range tanks doing a night cross country I looked at the gauges, decided to stop at Sechelt, dip the tanks to be sure, and sure enough there was plenty of fuel to get home with over an hour's reserve.
There's discomfort in many, and false comfort in some, fuel gauges.

What I suggest in types such as Cessna 172s, with consideration for the additional use of fuel from the left tank, while at the same time, for the same reason, considering this tank the best one for a go around, is this:

On a long cross country as you reach to within the last hour inbound, select the right tank only, and note the time.
If the engine fails, switch to the left tank and note the time.
How much time did the engine run on the low right tank?
Perhaps you have 2/3rds of this time left in the left tank. At least you know.
Now plan a diversion, or is your destination within this time? Perhaps a good precautionary landing can be carried out if you're very worried.

Of course if you make it to your destination on the right tank, then switch to left tank only for the approach and landing.
There will be a greater head of fuel in this tank which should continue to feed inspite of lazy rudder use in a go around.

I hate flying with fuel uncertainty.

[greggj]

The aircraft I'm flying a lot atm has a peculiar property, in that it will sometimes show 1/3 of fuel or less on the gauge when fuel goes below 1/2 in the tank. So, since I saw that first and last time, I now fuel up on every stop - doesn't matter if the fuel is £0.50 more expensive then at the base airfield. Fuel gauges, eh ?

[Keef]

Treat yourself to a dipstick. It's the only way to be sure.

[kanga]

Shareoplane has a high-tech piece of semi-rigid, semi-transparent narrow hose, notched with calibration markings. Dip through sideways-facing filler until bottom of tank felt, put thumb over top end, withdraw, read level. Very effective

[Rob P]

The Black Six has a highly accurate screen thing in the centre that tells me to a litre or two exactly how much fuel I have on board at all times.

Regrettably, it doesn't tell me where it is, and the twin fuel gauges for the tanks are well into chocolate fireguard territory.

Rob P

[hatzflyer]

Treat yourself to a dipstick. It's the only way to be sure.

I are one!

[IainD]

We have reasonably accurate fuel guages in the 9 but I still wouldn't trust them. Always dip the tanks and do a fuel plan from there based on 30l/h which is very generous.

[ray]

Many years ago I had a share in an Emeraude that had a float and wire type fuel indicator that was right in the centre of the combing in front of the perspex screen. It rose up and down as the fuel volume varied.

The best I have ever had and trusted it (but we still had a wooden dipstick for pre flight - to be sure to be sure ) haha

[CubLife]

The Cub has a super system - A clear sight tube running the depth of the wing and the level is the level... no possible fault is available that I can see!

[mick w]

I have a ' Wire on a Float ' Gauge , & know that once it reaches the Filler Cap , I have 15 -20 mns left . I then have an hour & a half in the Wing Tank , which is always full at the beginning of every flight .

[Rob L]

Mick: have you ever had the cork/wire fuel gauge stick (so apparently showing more fuel than you have)?

Also, it is worth calibrating your "15-20 mns".

Rob

[mick w]

Not stuck on this A/C Rob , but a Jodel 112 I had used to , when suspected I just stalled it , & got instant re-calibration .

The 15-20 mns has been calculated , the Engine fires up again on changing to Wing Tank !!.

[KNT754G]

Many years ago a friend and I flew to Newquay in a 182, it burned 60 litres an hour and had six hours endurance - it was full to the brim before we left Blackpool (visually checked)

Two and a half hours to Newquay, into a strong headwind. No steps at Newquay to visually check, but we knew how long we had been flying and we had an equally stiff tailwind on the way home.

Approaching Cardiff on the way back the gauges showed very little fuel remaining!
All possible calculations (including allowing extra fuel burn for the amount of carb heat we had used going down is solid IMC) said we had loads of fuel, but the gauges said different.

Decision to divert was easily made, the tanks held exactly the amount of fuel they should have held at 60 litres per hour for the time we had been flying, but there is no price on peace of mind. We departed again for home with full tanks and happy feelings, didn't care about the landing fee.

[kanga]

Many years ago ..

Decision to divert was easily made,.. didn't care about the landing fee.

This was before the Strasser scheme, I guess .. which shows its value today