Fuel dipsticks

[bonniejack]

Looking at fuel dipsticks and notice that most types are covered but not PA28. Is there something odd about the tank shape on PA28 or is there some other reason. I know there is the universal model but seems like a bit of a hassle calibrating it and wondered why manufacturer missing out on a big slice of the market.

[Comanche250]

As I understand it its to do with the dihedral of the wing, there's more fuel near the wing root end of the tank which cant be accesed from the filler cap as this is at a higher point, whereas say in a C150 the tank is horizontal and a dipstick will give an accurate reading along the entire length of the tank.

[bonniejack]

Thanks Commanche I should have thought of that, makes sense.
WR yeah a stick will do but still has the hassle of calibration. To be really anal about it better if not made of wood? Particles in system? Not metal risk of spark. Of course the plastic tube used in these dipsticks also gives you a sample to examine over the depth of the tank like a core sample. OK I'll go and take the pills and lie down for a while

[jabberwok]

Two problems with the PA28 dipstick. One is that even if you see bare metal through the filler cap there is still a moderate amount of fuel left so the stick is useless when you need to check critical levels. OTOH if you see metal it's time to refuel anyway.

The other point, which I guess applies to many aircraft, is that if the aircraft is not level then the fuel levels can vary dramatically and give very erroneous readings.

[bonniejack]

Once the level goes below the tabs it is hard to gauge how far below it is. Tried getting a better view by using cigarette lighter for more light but damned wind kept blowing it out. ;) So reached in and checked wet level on cuff. Must use other arm next time - watch seens to have stopped. Also seem to have lost a glove somewhere.

[The Nr Fairy]

When I learnt to fly R22s in Australia, the school used a calibrated cut-off broomstick, marked on one half with graduations for the main tank, and on the other for the aux tank.

Much better than metal as the wood stayed wet for a bit therefore easier to read, you don't need two bits to dip each tank (different shapes therefore quantities on the R22), and I never dropped one in the tank, unlike the crappy metal ones in aircraft I've flown recently.

[foxmoth]

When I flew Pa28s I always new 3 levels anyway (forgotten them now but should not be hard to find out), Full, Tabs and fuel at the bottom of the outer end of the tank, this gave a fairly good indication, if you were below the tabs and were not sure if you had enough you could put more in.

[bonniejack]

what really set me off thinking about the lack of accurate knowledge of fuel levels was the question of the weight of fuel when doing weight & balance. I guess all you can do is be pessimistic and use 17 galls(at the tabs) even if clearly lower. All this came from the Warrior versus cherokee thread which had me considering just how much fuel and how far you could go with 4 seats filled (in a warrior).

[Comanche250]

There are of course the fuel gauges that can be used as well, I know they arent all that accurate in a PA28 but if you are on level ground and you know that the level is below the tabs then you can at least get some idea of how much below the tabs the fuel level is.

As long as you have a fairly accurate idea of fuel level and are then a little over-optimistic when fuel planning everything should be okay, assuming you also know the fuel consumption.

C250

[RatherBeFlying]

Wooden Paint Stirrers are usually give-aways at your local paint store and take up little room in the cockpit.

The fun part is is calibrating them as you need to start with an empty tank and then mark every few gallons or litres.

Maybe you can run the fuel down to less than half tanks and pump the remaining gas into the other tank, but this only works when there's no connection between the tanks -- sometimes happens when fuel shut off; sometimes not:\