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ME
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Sep 1

Spar fuel valve

What is the purpose of the spar fuel valve? And why their two ? (spar fuel valve and fuel shutoff valve)

Hi Kok Kok,


The Spar Fuel Valve is located in the leading edge of the wing.

The Engine HPSOV is located in the HMU (Hydro-mechanical Unit).


The Spar Valve is there for a couple of reasons:

  • One being the redundancy,

  • the other reason is fire protection.

If the engine separates or there is a fuel leak from the engine, you need the spar valve to close in order to stop the fuel from leaking. In case of engine fire you want to stop the fuel from entering the engine section, hence the spar valve.


You might ask, why we then need the HPSOV in the engine? The reason is simple, if you wanted to shut-down the engine by only closing the spar valve, it would take approx. half a minute for the engine to run out of fuel and shut down. That's why there are multiple shut-off valves.


-Petr