Beagle Pup Series 1 Indicated Fuel Flow Issue
I have posted this question here, rather than in the Private Flying forum, as I know that a lot of airline pilots have many hours on type: would be grateful for any insight into something that our little beauty is doing.. .. .With the electric boost pump "on", the fuel flow in the climb is a healthy 5psi - when it is selected off at 1000' (with 2500rpm set) the reading drops to under 2psi.. .. .Having tested the a/c on the ground, this effect seems to be related to the power setting - e.g. at all settings with the boost pump on, the fuel flow is solid, but with it switched off, the higher the power setting, the lower the indicated fuel flow.. .. .The POH fuel diagram shows two flows, one directly to the mechanical fuel pump and then to the carb, the other via a one way (non return) valve through a separate line (which bypasses the mechanical pump and feeds the carb direct. Presumably this arrangement provides redundancy in the event of mechanical pump failure.. .. .The fuel gauge is shown as being linked to the bypass fuel line.. .. .It would thus appear that the indicated fuel pressure drops when the electric boost pump is selected "off" due to a reduction of pressure flowing through the bypass line, as the engine pump is working strongly due to the high rpms.. .. .I guess my questions are:. .. .1) - Have I understood the way the fuel system works?. .. .2) - In the experience of pilots with time on Continental engined Pups, is this normal?. .. .3) - I am wondering what the symptoms would be if the mechanical pump started to fail (would the indicated pressure tend to rise as the mechnical pump took less flow?. .. .-and-. .. .4) - Do I need to be worried about the situation?. . . . <small>[ 04 March 2002, 09:42: Message edited by: Final 3 Greens ]</small>