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Cardinalsteve
29th Nov 2008, 06:03
CRJ experts out there. Can anyone enlighten me on the fuel check valve "check". supposedly to be done on the first flight of the day. In the case that the valve does not function normally is this covered by the checklist and the MEL. I have heard that a large proportion of operators do not do this check. So is it mandatory or just recommended. What is the easiest way to check it.

Parkbremse
29th Nov 2008, 09:55
i don't have the mel at hand but i wouldn't be surprised if this is a no-go item... What you're actually checking is, that in the event of both boost pumps failure and an additional main ejector failure the check valve cuts out the fuel supply line from remaining main ejector to the failed main ejectors engine, because the fuel supply to both engines cannot be guaranteed by one main ejector alone. So one engine supply is cut out, which leaves you single-engine in flight but at least with full fuel pressure on the remaining good engine.

Concerning the first flight of the day, this is how we do it in our airline: We start engine no 1, then after it's stabilized we switch off both fuel pumps and wait for the valve to close (might take 10-15 seconds) and the eicas message (in addition to the fuel pump messages) RIGHT FUEL LO PRESS to appear. Then before engine shutdown after the first flight, we shut off engine no 1 first and switch off both fuel pumps and wait for LEFT FUEL LO PRESS to appear on the eicas.

Hope this helps a bit

CRJ2
29th Nov 2008, 10:02
We are doing this check on the first flight of the day...
Start the left engine first, switch OFF the fuel pumps (both!) and then wait for the "Right Fuel low Pressure"-Message. When the message appears swith on the fuel pumps again and start the right engine.
If the message doesn't appear after around 15 seconds dry-motor the right engine. If it's not comming ON after the dry-motoring the check-valve test failed, and as far as I know this is a NO-GO item!
After the first flight you have to shut down the left engine first, thereafter switch OFF the fuel pumps and wait for the "Left Fuel low Pressure"-Message...

Parkbremse was faster than me.... ;-)