Carburettor temperature?

[tuomas]

Hi Pete!

We have an issue on our Cessna simulator.

It uses the pretty excellent Real Air C172 flight model. but with a modification to use carburettor-equipped engine instead of the fuel injected version. This is, so that people flying on the sim can use the carb heat lever like on the real planes on our club.

Since we dont use FS gauges (but Simkits physical instruments) I have a problem: FSUIPC doesnt seem to know about carburettor air temperature. This is the gauge you check when you apply carb heat on the engine check before takeoff (and you can monitor it during flight of course to notice when there is a likelihood of carb ice)

The FS2004 Robinson R22 does have a carb heat gauge on the pedestal panel, but at least the FSUIPC SDK does not mention such a variable.

Would this be something that could be added in a future version of FSUIPC? We could then build a custom servo-driven gauge and control it via FSBUS.

Best wishes,

Tuomas

[Pete Dowson]

FSUIPC doesnt seem to know about carburettor air temperature. This is the gauge you check when you apply carb heat on the engine check before takeoff (and you can monitor it during flight of course to notice when there is a likelihood of carb ice)

The FS2004 Robinson R22 does have a carb heat gauge on the pedestal panel, but at least the FSUIPC SDK does not mention such a variable.

That's because I didn't know about it and no one ever asked before.

Would this be something that could be added in a future version of FSUIPC?

I think I've found it. I'll map it to:

Engine 1: 3828

Engine 2: 3768

Engine 3: 36A8

Engine 4: 35E8

They are doubles (FLOAT64) and in degrees Rankine.

Shame you didn't ask a week ago, I could have slipped these into version 3.40. Meanwhile I'll email a test version with this mapping, for you to test for me. Okay? Are you able to check in on FS2002 also? It may or may not be correct there, I'll need to know for the SDK.

Regards,

Pete

[tuomas]

That's because I didn't know about it and no one ever asked before.

;-) I think this is a new added feature on FS2004 - carb heat has been there before, but for example the Dreamfleet Archer AFAIK does not have a gauge for carb temperature. But the Robinson R22 does.

I think I've found it. I'll map it to:

Engine 1: 3828

Engine 2: 3768

Engine 3: 36A8

Engine 4: 35E8

They are doubles (FLOAT64) and in degrees Rankine.

Yeah. 3828 seems to work (checked with FSInterrogate since we dont have the gauge done yet for the sim) I cannot verify for more than one engine though since I dont have any planes with more than one engine that have carburettors. But the values seem correct and it reacts also to outside air temperature (nice finnish winter of -25C makes a neat cool carb temp and applying carb heat warms to a whopping -12C :))

Looks like it works, we are going to test it once I get back from a 2-week work trip - going to construct a gauge from Simkits parts and hook it to FSBUS with a custom gauge face. I'll show you pics once it is working :)

Shame you didn't ask a week ago, I could have slipped these into version 3.40. Meanwhile I'll email a test version with this mapping, for you to test for me. Okay? Are you able to check in on FS2002 also? It may or may not be correct there, I'll need to know for the SDK.

Yes, it gives similar values on FS2002 too. Although carb heat is a LOT more effective in FS2002 (-34C outside temp and carb heat rises carb temp to +22C - whereas on FS2004 rises to something like -12C) But then again, the engine seems better simulated on FS2004 in any case (mixture and other things) so it could just be a difference on the simulator modelling.

Thank you very much for the help :-)

//Tuomas

[Pete Dowson]

... it gives similar values on FS2002 too.

Good. Thanks for confirming.

Regards,

Pete