Avcon conversion electric fuel pumps

[marathonrunner]

I read a post somewhere asking about the use of the electric fuel pump. I was going through my paperwork this evening on another quest and found the limitations section for STC 806CE. It specifically states "Note: Turn Auxiliary fuel pump on in the event of engine-driven fuel pump failure" Nothing about for take off and landing or any other regime of flight.

For fuel pressure gauge It says Normal operating range 3-5 psi (Green Arc)
Maximum permissible pressure 8 psi(Red radial line)
Minimum pressure .5 psi (Red Radial Line)

I found all this in the Airplane Flight Manual Supplement which states that this document must be kept in the airplane at all times or attached to the FAA approved Airplane flight Manual...All that was in CAPS. HOpe this helps and I will be sending all copies of the STC and many 337's to headquarters soon as I just got them back from Washington

[minton]

Here is an interesting topic!

I have a 170B with the "Del-Air" 0-360A1A conversion. It uses basically the same installation as the Avcon conversion less a few stiffeners. I'm sure the AFM supplement is close to the same.

Heres my question to those who know: How would one know that the engine driven fuel pump has failed in flight with the fuel pump/fuel pressure guage being plumbed as installed? I see a small #3 90 degree fitting on the carb:?: Thats probably for the fuel press line. Is it to be used with a rubber flex line to the firewall? Does the fitting have a small restrictor oriface?

[marathonrunner]

YOu are correct, the 90 degree fitting on the carb is indeed fitted with a rubber hose to a fitting on the firewall that goes to the gauge,.

I can verify from personal experience that when the engine driven pump fails it does indeed read zero since the pump is now out of the system and you have only gravity feed from the tanks. The engine will continue to run without the electric pump but for safety I would turn it on and note that the pressure gauge should again become active. I check before start up that my electric pump is working. Doesnt mean it will be there if the mechanical pump fails but at least I know that it was working before I fired the engine up. Hope this helps