I fly a TB20…a great plane but with lousy fuel gauges (like many other GA planes) and with tanks that can’t be dipped. It really bothers me. I think the reason why the tanks can’t be dipped is because various ribs in the wing go through the fuel tank and so a dipping rod will simply hit the first wing rib. (One can’t position the dipping rod through the fuel tank inlet and then through the hole in the wing rib…I’ve tried.) So once about 130 litres of fuel have been used (out of 326 in total) the remaining fuel is out of sight of the fuel inlet and one is relying on poor cockpit gauges and perhaps a fuel totaliser to guesstimate how much fuel if any is left on board. (Totalisers don’t detect leaks of course, nor correct pilot errors regarding refueling amounts.)
It occurs to me that with cold LED lights and small video cameras becoming so prevalent, there must be a market for little remote cameras being mounted inside the gas tanks of such plane so that GA pilots no longer have to guess or rely on their fuel totalisers to make a stab at how much fuel is left on board.
Does anyone know if these are being developed or have I just forgone a fortune by suggesting this innovative valuable product to the world at large? 
This would basically require a medical-quality endoscope. These sell for the price of many smaller GA aeroplanes, which might be the only limiting factor next to the ridiculously conservative mindset of the GA industry.
Note that like with things labeled “aviation grade”, “medical grade” products are often sold with a Base price * X price multiplier, where X is by default a number that seems to have been created by throwing g at least two or more D6 dices…
@MedEwok, I’m sorry, I wasn’t clear. I meant permanently housed cameras inside the tanks, not an endoscopic examination as part of each pre-flight check.
I wonder if it’s possible simply to mount permanent cameras inside the tanks, with LED lighting. I can’t see why not.
Yes I understood you, just thought that kind of camera might do the job best. But I think I was exaggerating, for a permanent camera one could probably make do with a bit less image quality for a much lesser price. I like your idea very much. One problem might be that it doesn’t give quantitative but qualitative data, but pilots seem to love to crunch numbers…
I think one could get to quantitative results : just mark up the inside of the fuel tanks with level markings when installing the cameras. These could then be read when looking at the images inside the cockpit.
The later TBs have highly accurate capacitive fuel gauges, which is an adequate solution although a “visual” check would be the ultimate thing.
MedEwok, regarding boroscopes for aircraft owners the PUF’s test winner in August edition is Mike Bush’ Vividia VA-400 which sells for about $ 199,— …
No medical quality required, except if you want to determine whether the fuel in your tank is Avgas or Jet A
I have no idea at all, but have never heard of anyone doing it. For sure it would cost thousands, if it were legally possible. There might be a generic American product.
Why not just use a fuel totaliser, JPI etc, it’s what is done in the commercial world. Sure it doesn’t account for leaks, but PFI covers that….Mostly :-)
