Originally Posted by
Jabawocky
Sillo,
Couple of things here, the calorific values of fuels varies by tiny amounts, not worth the discussion point. The different octane ratings means you get to use the fuel with higher boost or higher compression ratio to achieve more power, while maintaining detonation margins that are acceptable. And acceptable varies from airplane to race car and everything in between.
As for if an EGT probe fails? Well no, once you are "known to be LOP" a probe failure matters not, because validation from all the others, your fuel low etc…..means the EGT probe is just validation of a know state.
You can comply with the POH supplement without even looking at the egt info if you want.
Ok fair enough if the probe fails and you are LOP at that time I agree you where compliant when it was set so that's fine, but what of the next flight ie returning to base let's say it's a two hour flight. Surely you can't comply then with a failed probe, your only option is to run ROP to be compliant. All this talk about that you must have good monitoring gear to go LOP which I agree with but when it fails it's still ok to go LOP?.
I can't see casa being happy with that, I know it is knit picking but this is where we end up with the regulator sometimes.
So now you are ROP for a few runs here and there and when the hundred comes up it turns out all is ok with the engine, great. However if at the hundred all is not well and you have a burnt valve or fried waste gate etc where do we point the finger LOP or ROP. Like all aircraft things break or go u/s and I am yet to see a machine that has some sort of magical wizard induced spell with such 100% reliability, isn't that why we have mel's.
So you have a MEL shouldn't this be on the MEL and if so what does it say , I'd like to see that page.