Magneto check issue

[tango4]

Hi again,
I encountered a strange issue when performing a mag check.
I have both engines running all magnetos on.
Now I increase the throttles to let's say around 2000rpm.
If I switch off the left mag on engine one, I see an RPM drop as expected. Now I turn it back on, RPM back to 2000RPM. This is what I expect. But if I switch off the right magneto at this point, engine is shutting down completely.

Am I missing something here ?

Charles.

[N918JC]

I have experienced the same behavior though it is not consistently present. I have had some possible success by turning the mags on from right to left at start up and I have not seen the issue if checking mags from right to left. It is so difficult to repeat the problem that I have not been able to do any reliable testing to confirm either of these though.

I have also suspected a conflict with my default flight but again, testing has been difficult to confirm. Frankly, I have yet to set up a 100% reliable default flight to fit my purposes; but that is an entirely different issue.

This is in P3Dv4.2.

Jesse Cochran

[N4GIX]

I just found and fixed a very subtle error in the logic gauge that may have had an affect as described. This will show up later today with SP3.2

[ThomasAH]

I just found and fixed a very subtle error in the logic gauge that may have had an affect as described. This will show up later today with SP2.2

Probably 3.2, last one was 3.1

I had this problem once, too, but could not reproduce it and thought it was due some other aircraft I had loaded before.

[N4GIX]

I just found and fixed a very subtle error in the logic gauge that may have had an affect as described. This will show up later today with SP2.2

Probably 3.2, last one was 3.1

I had this problem once, too, but could not reproduce it and thought it was due some other aircraft I had loaded before.

Thanks, fixed the version number. The logic error was so subtle that I never spotted it for more than ten years! It was only if one selected the mag switches in a very specific order that the system would go pear-shaped. You see, the sim (none of 'em) actually support separate left and right mag selectors per engine, so a bit of logical kung-fu is required to make it work.

[N918JC]

... so a bit of logical kung-fu is required to make it work.

And we all know you are the kung-fu master.

[ThomasAH]

Testing this using 180411 SP3.2 I just had the following situation:
After various regular magneto checks (from 2000 RPM, only one at a time) with no problems I turned off the right magneto of the left engine and the left magneto of the right engine. Now the right engine continued running (at slightly lower RPM), but the left engine stuttered and died.

After that it took me several tries to get into this situation again, and it was again the left engine that died, again with the same magnetos turned off.

After some more tries I managed to let the right engine die with only the left magneto of the right engine turned off and later the left engine with only its right magneto turned off. Once I even had it at after turning off one magneto after not having touched any magneto for about a minute.

But it seems only the "middle" two magnetos are affected, i.e. left engine's right magneto and right engine's left magneto.

So this is yet fixed, at least not completely.

(and I'm sure to have SP3.2, because the housing for the air stairs is there )

[N4GIX]

I've re-checked the logic, and found no problems with it. I did however take note that the left engine's right mag did 'kill' the engine 3 out of 32 toggles, as did the right engine's left mag switch albeit only 1 out of 32 toggles.

[Ron Attwood]

When this is finished, I'm going to miss my daily 310 updates! (Still recommending it )

[tango4]

Many thanks for this supersonic update !

[ThomasAH]

I've re-checked the logic, and found no problems with it. I did however take note that the left engine's right mag did 'kill' the engine 3 out of 32 toggles, as did the right engine's left mag switch albeit only 1 out of 32 toggles.

For me it is much more often on the ground, and almost guaranteed to cause problems when doing this while airborne.

[Krazycolin]

I've asked Bill to take a closer look at this but he's got something else to do beforehand so this will have to wait a bit. (a bit= not sure but within a month or less)

[N4GIX]

For me it is much more often on the ground, and almost guaranteed to cause problems when doing this while airborne.

Why would you be doing a "mag check" while airborne anyway?

[ThomasAH]

For me it is much more often on the ground, and almost guaranteed to cause problems when doing this while airborne.

Why would you be doing a "mag check" while airborne anyway?

I was testing the "hydraulic hose or wheel poking through various parts of the wing" issue, which is only possible with a retracted gear, i.e. in the air, then I thought: "Hey, it may be interesting to see how a failing mag would affect the engine during cruise flight"