G'day guys,

I passed AGK with 79% but I do have a query

There was a question in the exam that said this:
"You have ordered 100/130 octane avgas from your contractor. You conduct a water check and find that the fuel is clear."
"What fuel has been loaded"

Without hesitation I selected Avtur as I knew this was the correct answer, but "aviation fuels" appeared on my KDR's and that was the only question I received about it

Is anyone able to clear this up for me?

Cheers

Hi,

I did the AGK test today (pass) and experience the exact same thing. Any thoughts?

Luca

Hi guys,

The thing to realise here is that you already have AVGAS in the tanks when you asked for the refuelling. If you had received Jet A1 by mistake, the kerosene will dissolve into the AVGAS and the mix will take on the light blueish colour of the AVGAS (*).

If you have taken a fuel sample, and it is perfectly clear, you will almost certainly have water in the fuel. You could only get a clear sample that wasn't water if the tank was bone dry when you ordered and you had received 100% JetA1 - or 100% water of course .

Cheers,

Rich

P.S. Thanks to Mark at Archerfield Refuellers for confirming this

Ermm I stumbled across this one.. and sorry I don't quite understand the answer.
100/130 Avgas is green in colour.

If you had some in the tank already, and you loaded some JetA1 in by mistake how does it turn light blue?
Is the question saying you have just taken on very contaminated fuel (100% water volume in the water check?)
If it is 100% water, then how would you know what fuel got loaded anyway?

Yep, sure is dav and you're right. Since you don't see 100/130 anymore, I defaulted back to thinking about 100LL and talked about the bluish colour. The answer still stands though, whether the fuel is blue or green. If you get a clear sample it is most likely water.

How would you tell the fuel grade you had received? Keep draining the water out until you start getting fuel in the sample.

Cheers,

RIch

Thanks Rich that makes sense to me now.

I know this is a late post, however for anybody reading. Another thing to consider is that Jet A1 is straw colour, not clear completely. So if the question said clear, you can presume with confidence they aren't talking about Jet A1 or Avtur, which is still a different colour to clear water.

Another thing to consider is that Jet A1 is straw colour, not clear completely

Not necessarily .. AVTUR can range in colour from colourless through to straw shades .. maybe my eyes are the problem but it always looked pretty clear and colourless to me when I drew short straw and had to do the drain checks. However, Rich's answer makes the most sense .. water contamination.

One of the reasons most folks test AVTUR with water-detecting paste is due to this colour problem as well as AVTUR's miscibility with water .. ie you can't rely on seeing the sort of water/fuel demarcation line that you get with an AVGAS drain sample check.

Those AVTUR folks who don't use paste are tempting fate, methinks ...