Bill Freeman wrote:

Paul,

We discussed this at length some months ago.  I recommend the fuel be
either returned to one tank at all times, or buy the expensive dual
selector to reroute fuel to the originating tank.

The single return is very simple, cheap and light - all very attractive in
aircraft parts.  This system does mandate TO and initial operation on
that tank until enough fuel has been burned down to deal with the
pax possible return flow from another tank.  This was used on (at least)
older Bonanzas, and works just fine.  No transfer pump is required,
just a bit of care in fuel managment.

The route-back-to-same-tank system requires the dual selector valve.
The Andair fuel selector valves that I have examined are really
beautiful, very high quality, but of course you pay for that quality.  Extra
cost, extra weight, extra complexity at a gain in operating simplicity.
Pay your money, take your choice.

Several of us pointed out the risk of returning bypass fuel to the header
and it was not taken very seriously.  I am very pleased that Ed has had
no serious problems and has been safe, and I hope others will heed his
lesson.  As I have stated in the past,

  FUEL SYSTEM DESIGN IS *VERY* CRITICAL AND NONOBVIOUS

and it is a wise person that precisely copies an existing, known-reliable fuel
system.  Fuel systems do NOT behave the way you would expect.  Many
people have died to verify this, and we don't need anybody else to get hurt.
Please experiment with other parts of the airplane and  use a known-reliable
fuel system design.

Stay safe.

Bill

I don't think you saw this Bill so here it is again.
New special EFI valve from Andair I saw at S&F. $155.00

Paul Lamar
 
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