Robinson R44 air filter problem, total engine failure, autorotation landing

[ericferret]

Aah a suspension of the law of gravity!!!!
Interesting.

Vertical mounted carburretor so any moisture in the venturi will drain down in to the filter housing and out through water drain holes probably mixing with any moisture trapped in that area which has entered via the induction system.

Given the heat in the engine area you would have to have your spanners out pretty damn quick to find evidence of this phenomenom.

[topendtorque]

But if the venturi blocks due to icing, the engine stops and later the carb is inspected, the ice will have melted and left water in the carb

Crab this ain't a rocket engine.

As Eric says ice forms in the venturi, outside the carburettor. If our good engineer (who is probably enjoying this charade) drains water out of the carburettor he drains it out of the carby bowl, where it has got in via the fuel line from the dirty fuel in the fuel tank.

Carby ice forms from atmospheric air when it goes past the carby via the venturi (which adjoins the carby as part of the same structure) en route to the engine and never gets into the carby.

To stop air getting into the carby there is a fuel deck pressure which is the weight of fuel in the carby as it is let in via a float valve from the tank due to gravity on a normally aspirated system. On a turbocharged system the fuel deck presure in the carby is balanced with the fuel pressure pumps against or more than the inducted turbocharged airflow pressure, so that the inducted air - and fuel - cannot go the wrong way.

A pressure differential is provided by a lower pressure in the venturi to suck fuel from the positive pressure in the carby bowl to the engine via the mixing ports in the venturi.

Water in the carby is dirty fuel.

Carby ice is an atmospheric condition causing ice in the venturi which impedes the normal fuel/air flow to the engine.

Another can and perhaps a rum chaser for the ginger beer please.

cheers tet

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Tet - I'll bow to your superior knowledge of the machine in question - my wife hasn't allowed me near a Robinson since I ended up in one on its side in a field nearly 20 years ago

[topendtorque]

Crab,

No worries, my first wife bailed up on me riding bulls in rodeos too when first we married, gees nearly 40 years ago, time flies.
It sounds as if you won’t be able to accept the invitation to fly with one of your local experts in a spot of R22 VRS either to give us your opinion on that. That is sad, tell your wife not to worry.

To counter that you are both cordially invited over here and I’ll take her up first whether she can fly a machine or has never sat in one and I’ll talk her through a few. Then she can give her seal of approval for you to come up and do a couple. Of course I’ll make sure she has a few pointers for you to follow?

There will be a couple of bits of extraneous activity, branding 300 kg very strong calves for a start, after you help me get them into the yard, also right at the moment we are into a nice drop of brown top Bundy OP. Very smooth. The couple of beers I had set aside for Nigelh I had to give away, as he hasn’t showed up yet but when you are coming we’ll let him know, he may turn up to amuse himself. I may have gone up in his stocks, I am actually rated on a squirrel nowadays, please don’t tell too many people.
cheers tet - regards to your wife

[RVDT]

I am actually rated on a squirrel nowadays, please don’t tell too many people

Have no fear! We won't.

[[email protected]]

Thanks Tet, she has actually been in one when I was hours building for my 1179 and she hated it, especially after having flown in 'proper' helicopters like the Wessex, Gazelle and Sea King

I did do the incipient VRS demo on the Robbie but the CAA want to see an early recognition and recovery so it never gets far into it.

Branding sounds like fun - I might just take you up on the offer