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c172p-team / c172p

A high detailed version of the Cessna 172P aircraft for FlightGear
GNU General Public License v2.0
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model pitot icing #50

Closed gilbertohasnofb closed 1 year ago

gilbertohasnofb commented 9 years ago

PRC12 - model pitot icing

legoboyvdlp commented 6 years ago

I have a simplistic icing model on the IDG-A32X... it's basic, but it works. The real problem is modelling the effect it has on the instrumentation.

And the pitot cap should also affect the icing rate as well... :)

legoboyvdlp commented 6 years ago

image

If icing goes on long enough the drain probes freeze as well - so, the dyanmic pressure is completely unchanging, and airspeed indication will be unchanging with relation to airspeed - as altitude changes, thus static pressure, then the airspeed indication will change with it.

callahanp commented 6 years ago

Today I went to an open house at a local airfield 6B6. I got a chance to talk to a pilot's spouse who researched acquisition and maintenance of theirC172 heavily. He knew quite a lot about the various models. They bought a 1999 version.

While walking by the covered pitot tube, I mentioned this thread. He said he learned from experience, that a pitot tube left uncovered after a flight attracts mud dauber wasps who quickly gum up the works. Not sure what they did to get them out. Turns out these insectes arenotorious for this. https://en.wikipedia.org/wiki/Mud_dauber & https://en.wikipedia.org/wiki/Mud_dauber#Airplane_incidents

-Pat

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legoboyvdlp commented 6 years ago

Perhaps this could be like contaminated fuel, a random chance?

dany93 commented 6 years ago

As the measurement (pressure) is done in principle with a zero flow, I would rather expect a brutal (at least rapid) effect. As long as there is a small hole left, the pressure will establish (possibly more slowly on changes, but is it noticeable?). The only thing that can give a very small flow is the leaks in the pipes between the pitot tube and the instrument. This, in principle... Nothing is perfect and instantaneous.

It would be very different for a pipe with a flow (fuel from a tank to the carburetor). The VSI would be an intermediate case (measurement is based on a small leak)

I once had this IRL and there was no visible airspeed indication.

gilbertohasnofb commented 6 years ago

Perhaps this could be like contaminated fuel, a random chance?

Might be a tad too much IMO. From my understanding, these issues with insects and pitot tubes are much more common in certain parts of the world and in certain types of weather. The fuel contamination check is part of the checklist and has a very precise procedure which must be taken into consideration before flying. Personally I think it would be really too much to implement this insect thing in the same way.

callahanp commented 6 years ago

Yeah, too much.

I'm not asking for this, but it's fun to imagine simulating a number of wasps coming out of the pitot tube and chasing the walker or landing on the windshield after starting up. We can leave this to the entomologists among us to implement.

So what's next? Bird Strikes? ;-)

-Pat

I was stung at age 4 by a number of angry hornets. I was curious to see them so I kept pedaling my toy tractor into the garage door where they attached their nest until they came out to play. I'm still not afraid of stinging insects, but very respectful.

On Sun, Oct 21, 2018 at 8:08 PM Gilberto Agostinho notifications@github.com wrote:

Perhaps this could be like contaminated fuel, a random chance?

Might be a tad too much IMO. From my understanding, these issues with insects and pitot tubes are much more common in certain parts of the world and in certain types of weather. The fuel contamination check is part of the checklist and has a very precise procedure which must be taken into consideration before flying. Personally I think it would be really too much to implement this insect thing in the same way.

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hbeni commented 1 year ago

IIRC this was already implemented recently. My log confirms this.

26.12 [INFO]:nasal      creating PitotIcingHandler for /systems/pitot[0]
26.12 [INFO]:nasal      creating StaticIcingHandler for /systems/static[0]

Commit for the pitot was this: b4e0d0a7f26d44f365

wlbragg commented 1 year ago

Thanks, yes.