Rino Lacombe wrote:

With independent lines from the tank?
How about a check valve at each pump outlet?

Rino

Also good ideas. Some pumps have check valves built in.

Paul Lamar

Bill Freeman wrote:

I vote for separate check valves since the pump may have
eaten itself while failing, making depending totally on its
check valve to make the parallel pump function would be
risky.  Long EZ has pumps in series (mech and elec) which has
some risk of one failing and killing the other.  No reports
yet of this happening, but I worry about it and have considered
replumbing for parallel with check valves.  BUT -

"Simplicate and add lightness" has prevailed . . . .  so far.

Bill

Bill
Long EZ builder & pilot
mechanical engineer

Had it happen to me in a Mooney. The boost pump failed and vane particles killed
the mechanical pump. The engine stopped with a bang. I thought at first it
threw a rod or something.  Fortunately I was over Lordsburg NM airport at the 
time and was able to dead stick it in. An AD on the boost pump was pencil whipped.

Paul Lamar
 
The AirCraft Rotary Engine NewsLetter.              Powered by Linux.

http://home.earthlink.net/~rotaryeng/            http://www.linux.org