> -----Original Message-----
> [mailto:[EMAIL PROTECTED] On Behalf Of 
> David Megginson
> Sent: 27 July 2004 12:39
> To: FlightGear developers discussions
> Subject: Re: [Flightgear-devel] Tried the Spitfire
> Vivian Meazza wrote:
> > I don't think that's intrinsically very difficult to simulate right 
> > now. When certain conditions are met, if carb heating is 
> off, weaken 
> > the mixture over time (until the engine stops?). If carb 
> heating is on 
> > enrich the mixture over time until power is restored. The 
> conditions 
> > are actually aircraft and engine specific, I think, but a general 
> > solution might be near enough for government work.
> With carb ice, the engine dies from an excessively rich 
> mixture (all fuel, 
> no air), not an excessively lean one.  The best way to 
> simulate an ice 
> blockage would be to reduce maximum available manifold 
> pressure and let the 
> piston engine model work out the rest.
> When there is no actual carb ice, carb heat makes the intake 
> air hotter, and 
> thus thinner, so the mixture also becomes richer (more fuel, 
> less air), but 
> in this case not usually rich enough to stop the engine.
> The normal rule of thumb is that applying carb heat will 
> decrease your 
> power, but that's not true for those of us who fly lean of peak.
> > Pitot head icing is another candidate. Actually it's so obvious, I 
> > wonder if someone will tell us that it is already an intrinsic 
> > function?
> We don't actually have code to create pitot ice (or melt it 
> when pitot heat 
> is on), but you can simulate pitot icing by setting the 
> /systems/pitot/serviceable property to 'true'.  You can also use 
> /systems/static/serviceable to simulate a static-port blockage, 
> /systems/electrical/serviceable to simulate an electrical 
> failure (battery 
> and alternator, I guess), and /systems/vacuum[n]/serviceable 
> to simulate a 
> failure of a vacuum pump.  All of the instruments should respond 
> more-or-less realistically to the failure.

I knew someone would know. Yes of course carb icing makes the mixture over
rich - leaning it was a quick stab at reducing the power. Your suggestion is
obviously the way to go. Much more realistic. Thanks.

I think we could easily extend the existing pitot stuff to be a bit more
realistic with some nasal.

Bit of a roundtuit I'm afraid though, I really ought to finish the Spitfire




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