Chained incidents in LFMD (a twin Comanche down - possible fuel contamination)

You won’t get enough water after refuelling to cut the engine unless it’s visible by naked eye when sampling and its everywhere: water takes time to settle with high concentration in the pipes, meanwhile an aircraft flying in cruise will be mixing water & fuel on high RPM & high ASI with no issues just like an engine running on fuel + water while flying in heavy rain

The fun starts in initial climbs with low RPM & low ASI after:
- landing, fuel, taxi, park for lunch then takeoff the afternoon
- landing, fuel, taxi, park for night then takeoff the next day

Holy sh**, what a horror. Keep this updated! So sad that a Twinkie went down, good to hear that the pilot made it out. But chances are 99,9% it will never get airborne again. One less.

I just spent a few days in Cannes. We refueled 90 minutes after the twin ditched. Today I was unsure how to proceed for my return flight. As far as the airport could tell, as a preliminary finding, there was no anomaly found with the avgas at the pump. After careful draining and checking for water – and if JetA1 would show up with the paper test – I did a thorough run-up. The flight home was entirely uneventful.
So probably no link between the two separate events.

Bleriot wrote:

So probably no link between the two separate events.

Which, after all, would have been the most probable outcome anyway.

greg_mp wrote:
Anyway I have never seen a pilot doing a tank drain after refuel

Quote

There’s been a documented case of an entire tanker load of water being delivered to an avgas tank at an airport in error. The pilot that noticed it after doing drain checks was struck by the absence of colour in the sample and how long the liquid took to evaporate.

Bleriot wrote:

JetA1 would show up with the paper test

What is that?

Bleriot wrote:

I did a thorough run-up

I think the key is to run the engine at higher fuel flows for longer so the engine really takes a lot of actual fuel from the tanks. Else there might still be good fuel in all the lines, filter, catch tanks etc. and only after take off the engine really gets the bad fuel. A piston PA46 was once fueled with JetA1 on Easter island and according to the reports it did manage to take off and only then the problems began. Those engines are just too fuel efficient at ground idle;-)

Sebastian_G wrote:

I think the key is to run the engine at higher fuel flows for longer so the engine really takes a lot of actual fuel from the tanks.

True, but won’t work in all installations. For example the C210 has 5 USG header tanks, so you’d need to ground run the engine for an awfully long time.

JetA1 would show up with the paper test
What is that?

Water contamination is easily detected in a sample of avgas. Jet fuel on the other hand is more difficult to detect. The presence of jet fuel doesn’t alter very much the blue color of avgas, neither can you easily smell it if only a small quantity is present. If you put a couple of drops of avgas on a sheet of white paper the jet fuel will leave a halo after the avgas evaporates.