-----Original Message-----
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of Jim Sower
Sent: Wednesday,
March 17, 2004 8:27 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: mainfold hose
<... Do you suppose that this wouldn’t react
fast enough to keep the engine running? ...>
Even if you didn't have the automatic switchover, I bet YOU would react fast
enough so the prop would never stop. What I wonder about is with auto
changeover, how do you know the primary pump failed?
I wouldn’t. I’d only
know that the pressure went too low. Light on panel shows backup pump
running.
And how would you be able to shut down the
engine by turning off the pump
The backup pump has an “enable”
switch (enables auto switch-on) and “on” switch. Both off
means pump is off.
? I assume that if the auto changeover fails, you can still turn on the
backup manually.
Yep .
Al
Al Gietzen wrote:
If you are flying and running only one h.p. fuel pump,
and that pump fails, the engine will become silent only milliseconds
later!
This
is interesting. As my circuit diagram is currently configured, I have a
pressure switch in the fuel system which automatically turns on the backup pump
if the pressure drops below about 30 psi. (don’t remember now the exact
setting on the pressure switch). Do you suppose that this wouldn’t
react fast enough to keep the engine running?
There is a manual bypass so I can turn the pump on if I want. The idea
was to turn on both pumps for takeoff, but at other times the backup would
automatically kick in to keep the engine from stopping if the primary pump
stopped; thereby avoiding rapid heart rates on the part of pilot and
passengers.