If a piston aircraft is accidentally mis-fueled with Jet A the engine will run just long enough to takeoff, then quit within minutes. The aircraft goes down, with a full load of unusable fuel.

The solution is easy you say! "Don't put jet fuel in a piston aircraft". But human error always finds a way. Pilots check their fuel for water and contaminants, but if Jet A is mixed with 100LL the standard visual test isn't good enough, it is almost impossible to see the difference between the two. Smelling it won't help either. The only way to make sure that 100LL isn't contaminated with jet fuel is by rubbing it with your fingers, or pouring some on paper and waiting to see if it evaporates. These are time consuming and therefore never done.

A nifty safety feature (available as a costly option, of course) would be a detector in the fuel tanks which could use electrical resistance to determine if the aircraft was mis- fueled with Jet A or water.
-- DIYMatt, May 10 2015

BYO jet fuel BYO_20Avgas
[not_morrison_rm, Aug 17 2015]

How about adding different dyes to distinguish the fuels?
-- MaxwellBuchanan, May 10 2015


^ Red dye has long been added to off road diesel fuel in the US because no road tax is imposed on it. Road fuel has no dye. If caught using the red stuff in a road vehicle to save money it's a stiff fine. Good idea [MB].
-- cudgel, May 10 2015


They do color code them. Jet A is clear, and 100LL is light blue, so if you mix them together they still look light blue. I believe 80 octane Avgas is red, 100 is green.
-- DIYMatt, May 10 2015


(marked-for-tagline)

" But human error always finds a way "
-- normzone, May 10 2015


[+], but resistance probably won't work. Density or capacitance might.
-- 8th of 7, May 11 2015


It is. You will be Assimilated. You must comply.
-- 8th of 7, May 11 2015


Comply with what?
-- pocmloc, May 11 2015


The Voices In Your Head, of course - what else ?
-- 8th of 7, May 11 2015


I'm pretty sure you could tell the difference using a refractometer. Could you simply embed one of these in the tank? I'm sure that a light source, refractometer and cell- phone style camera could be made to work for $100* or so.

*it's aviation, call it $15,000
-- bs0u0155, May 11 2015


Military aviation, call it $150,000 ...

Or just make the fuel filler holes and nozzles different shapes and sizes ... or is that too simple ?
-- 8th of 7, May 12 2015


//Or just make the fuel filler holes and nozzles different shapes and sizes ... or is that too simple ?//

Well, some fill from the bottom, some the top, some have the whole intert gas thing going on, some aircraft need 80,000 galons of fuel, meaning you're likely to need more than one size of hole. Actually, let's standardize the holes, I'd love to see a Jet Provost with the fuel filler from an A380.
-- bs0u0155, May 12 2015


Surprised they don't have this. Even if it's not necessary I'd want one. What's wrong with another gauge telling you not to worry? [+]
-- doctorremulac3, Aug 17 2015


Two contact points, a couple of overvoltage protectors, a single thin data line to the cockpit. Even I could make this.
-- Voice, Aug 17 2015


You could run it through an Intrinsically Safe Zener barrier, but ehat's the sensing technology ?

// Even if it's not necessary I'd want one. //

[marked-for-tagline]
-- 8th of 7, Aug 18 2015


//refractometer and cell- phone style camera could be made to work for $100* or so. it's aviation, call it $15,000//

Unless it's a government contract, call it $150,000. That's for the bid, it won't end up being that cheap.

Once its manufacturing gets incorporated into a jobs program titled "Operation Can't Possibly Fail" the research will be done in California, the case will be made in Kansas, the parts will be made in Texas and the assembly will take place in Nevada. This amendment will be tacked on to a bill being put through congress assuring that baby seals in zoos are given their moment of zen three times a day and will be sponsored by senators from California, Kansas, Texas and Nevada.

The bill to find out why all the parts don't fit together will be titled "Operation Can't Possibly Fail A Second Time."
-- doctorremulac3, Aug 18 2015


//The bill to find out why all the parts don't fit together will be titled "Operation Can't Possibly Fail A Second Time."//

In the absence of a fuel quality sensor... my cynicism sensor's off the scale right now.
-- bs0u0155, Aug 18 2015


//In the absence of a fuel quality sensor... my cynicism sensor's off the scale right now.//

I like to think of it as paying attention, but I could probably radiate a little more sunshine in my comments. But remember:

"Paranoia is just another form of awareness, and awareness is just another form of love.": Charles Manson. (And yes, that's an actual quote.)
-- doctorremulac3, Aug 18 2015



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