Hi pilots,
today I made an experiment to see how realistic the failures are simulated.
We begin with a dangerous situation with low oil pressure in the left engine IDG generator.
The warning appears.
The generator is switched off, and having the generator off-grid takes off all torque load from the generator drive shaft. The temperature is decreasing, but the low oil warning stays on.
So we have to take the IDG off the engine auxiliary drive shaft with a covered button. It feels like opening the self-destruct button but it´s for the wellbeing of the generator.
I am going to contact Fenix because when decoupling the IDG drive shaft, the switch should have an illuminated OFF label. This is probably a small bug. I am going to check this later on the private Airbus that is parking right next to my Ferrari behind the mansion, but for now I assume it´s a bug.
Now with IDG and generator fully decoupled from the engine, the IDG system temperature starts to decrease.
Kerosene has an oil-like viscosity and it is used to cool the generators. Kerosene is pumped out of the inner tank, sprayed on the generator, and running into the outer wingtip tank.
That´s why the fuel in the wingtip tank is always so much hotter than in the inner tank.
Let us see if Fenix has simulated the IDG cooling system in a correct way, and wait a little bit and see if the fuel in the left tank is cooling down while the fuel in the right tank heats up a little bit 
Excellent, after waiting for 20 minutes the kerosine in the left inner tank cooled down to 1°C and the outer wingtip tank is even -3 below zero, while the fuel in the right inner tank has +3 and +1.
It´s a very slow process and it will probably take a full hour or two until the new tank temperatures are stabilized, but even after a few minutes after shutting down the IDG you can see the imbalance of the fuel temperature:
Now you ask: But is there anything else to heat up the Kerosene in the tanks when the generator is switched off?
Because it begins to freeze @ -36° Celsius…
No it´s not 
And this will lead us to the next interesting experiment, what happens when flying through -70°C cold air with no IDG fuel heater on one wing, and without X-feed on?
Will the fuel freeze and will the left turbine getting starved of fuel?
For this experiment just leave the Autopilot on for a few hours during an extra-cold winter flight in extrafresh air, and see what happens.
Have a good flight Fenix-engineers and pilots out there! 
And a cool weekend.