Ed Haywood
En-Route
My 78 Super Decathlon has the original mechanical engine gauges. I've convinced myself I need to swap the fuel and oil gauges for electric to get the hot pressurized fluid lines out of the cockpit. I'm also jonesing for 4 cylinder EGT/CHT and fuel flow.
I already replaced the oil temp gauge with electric when the capillary tube broke. Oil P is simple and cheap to replace, but TSO electric fuel P gauges with >30 PSI range are expensive. That is pushing me towards an engine monitor or a combined FP/FF gauge like the EI FP-5.
How realistic are my concerns about mechanical gauges? I know they have been around forever, so they must be pretty reliable. Is there any history of fuel pressure gauge lines breaking and causing fires? My plane has a lot of fuel lines in and around the cockpit, and a header tank for inverted flight hanging over my lap. But those are gravity fed, while the pressure gauge line is at 30 PSI. I keep picturing hot vaporized fuel spraying all over me and the wiring behind the panel.
I noticed FAR 23 requires a check valve. Does that immediately cut off flow if the gauge line breaks? Is there a way to check function? All I see on my parts diagram is a fitting.
Last question: my oil P gauge line has a switch plumbed to trigger the Hobbs. If I have no intention of ever renting the aircraft, is there any reason for keeping the Hobbs or can I toss it?
I already replaced the oil temp gauge with electric when the capillary tube broke. Oil P is simple and cheap to replace, but TSO electric fuel P gauges with >30 PSI range are expensive. That is pushing me towards an engine monitor or a combined FP/FF gauge like the EI FP-5.
How realistic are my concerns about mechanical gauges? I know they have been around forever, so they must be pretty reliable. Is there any history of fuel pressure gauge lines breaking and causing fires? My plane has a lot of fuel lines in and around the cockpit, and a header tank for inverted flight hanging over my lap. But those are gravity fed, while the pressure gauge line is at 30 PSI. I keep picturing hot vaporized fuel spraying all over me and the wiring behind the panel.
I noticed FAR 23 requires a check valve. Does that immediately cut off flow if the gauge line breaks? Is there a way to check function? All I see on my parts diagram is a fitting.
Last question: my oil P gauge line has a switch plumbed to trigger the Hobbs. If I have no intention of ever renting the aircraft, is there any reason for keeping the Hobbs or can I toss it?
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