On the Whirlwind Mk 10 there is a small fuel line from the forward pump outlet leading back to the tank with a NRV. On one occasion the NRV stuck open when the pump failed and with the engine sucking fuel allowed air in the system as the line ended above the fuel level and the engine flamed out. After that there was a procedure to switch off the pump with the engine running to ensure that the NRV was working.
Last edited by Oldlae; 1st Jan 2014 at 13:54.
Reason: More detail