Re: Carb ice (was Re: [Flightgear-devel] Tried the Spitfire)
David Megginson wrote: Matthew Law wrote: I agree totally. Does FG define humidity at all? Yes -- we report it, and I'm pretty sure that we use it in density altitude calculations (so that it affects both true airspeed and engine performance). METAR reported humidity is also used. Erik ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: Carb ice (was Re: [Flightgear-devel] Tried the Spitfire)
Matthew Law wrote:
I agree totally. Does FG define humidity at all?
Yes -- we report it, and I'm pretty sure that we use it in density altitude
calculations (so that it affects both true airspeed and engine performance).
We're drilled to use carb heat before making any major reduction in
power (below the green arc) on the C152 and C150 and in/near
precipitation if icing is suspected. I've never read the POH for these,
I just do what my instructor tells me.
The Continental engine on the C150 (and presumably 152) and the older 172s
and 182s is often referred to by pilots as an ice maker: it has about the
worst possible design for carb ice, so you absolutely should be using the
carb heat for any power reduction, even if the OAT is 25-30 degC. As I
mentioned, 172s built after 1967, and Cherokees, do not have the same kind
of problem.
We lost a C150 last week to suspected carb ice. The engine stopped dead
on base leg when the pilot (a recent PPL graduate) throttled down to
descend for landing. The 'landing' appears to have been rather hard as
the 'plane is a write-off. Thankfully he's OK... I think my Vans RV-9
will have a diesel engine :-)
Sure, or a fuel-injected engine, or (as I mentioned) a Lycoming O-320, which
has a great record. Of course, we're all waiting for the big hydrogen
engines ("I'll take 25 liters of water, please"). If I were building my own
plane right now, I'd probably go for a fuel-injected engine like the IO-360,
so that I could add Gamijectors and even out the fuel/air distribution for a
nice smooth, quiet engine. Of course, hot starts in a fuel-injected engine
are quite a challenge ...
Avoid Rotax engines -- they're so advanced that they do not even need carb
ice to stop running (the flight school next to our flying club has three
Katanas: they've already had two forced landings bad enough to result in TSB
reports, and who knows how many uneventful ones on runways; no serious
injuries, though).
All the best,
David
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Re: Carb ice (was Re: [Flightgear-devel] Tried the Spitfire)
David Megginson wrote: I don't think we should disable any systems, period, but we can put users by default in situations where carb icing is unlikely (i.e. a clear, dry day). Once you get into situations where carb icing is likely, users are going to be dealing with other problems like reduced visibility anyway. I agree totally. Does FG define humidity at all? - from what I've read and understood on my PPL course and in the UK CAA leaflets the major component of carb ice is the humidity and temperature combination. We're drilled to use carb heat before making any major reduction in power (below the green arc) on the C152 and C150 and in/near precipitation if icing is suspected. I've never read the POH for these, I just do what my instructor tells me. Carb icing is common on humid days in certain Continental engines such as the one in the Cessna 150 and the old (pre-1967) 172, but it is very rare in engines like the Lycoming O-320 (used in the Warrior and post-1967 Cessna 172's). The warnings in the later 172 POH's about using carb heat at low power are left over from the old Continental O-300 days -- the Warrior has essentially the same engine, but my POH does not recommend carb heat for low power operation unless I suspect actual icing. We lost a C150 last week to suspected carb ice. The engine stopped dead on base leg when the pilot (a recent PPL graduate) throttled down to descend for landing. The 'landing' appears to have been rather hard as the 'plane is a write-off. Thankfully he's OK... I think my Vans RV-9 will have a diesel engine :-) All the best, Matthew. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
Re: Carb ice (was Re: [Flightgear-devel] Tried the Spitfire)
David Megginson wrote: I don't think we should disable any systems, period, but we can put users by default in situations where carb icing is unlikely (i.e. a clear, dry day). Once you get into situations where carb icing is likely, users are going to be dealing with other problems like reduced visibility anyway. I agree totally. Does FG define humidity at all? - from what I've read and understood on my PPL course and in the UK CAA leaflets the major component of carb ice is the humidity and temperature combination. We're drilled to use carb heat before making any major reduction in power (below the green arc) on the C152 and C150 and in/near precipitation if icing is suspected. I've never read the POH for these, I just do what my instructor tells me. Carb icing is common on humid days in certain Continental engines such as the one in the Cessna 150 and the old (pre-1967) 172, but it is very rare in engines like the Lycoming O-320 (used in the Warrior and post-1967 Cessna 172's). The warnings in the later 172 POH's about using carb heat at low power are left over from the old Continental O-300 days -- the Warrior has essentially the same engine, but my POH does not recommend carb heat for low power operation unless I suspect actual icing. We lost a C150 last week to suspected carb ice. The engine stopped dead on base leg when the pilot (a recent PPL graduate) throttled down to descend for landing. The 'landing' appears to have been rather hard as the 'plane is a write-off. Thankfully he's OK... I think my Vans RV-9 will have a diesel engine :-) All the best, Matthew. ___ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel 2f585eeea02e2c79d7b1d8c4963bae2d
