<... I don’t see allot of them burning along the highways ...>
Actually, I DO see some burning.  Not every day, but enough to notice.  IIRC nearly ALL airplanes have an emergency fuel shutoff.  Even if they ALL didn't, I certainly would.  That said, to have the Master the only way to shut off fuel in an emergency defeats practically all of the other procedures you might want to avail yourself of in the event of a fire - like navigating, communicating your problem to someone else (like ATC), doing anything useful at all if the problem occurs at night, etc .  To be honest, I cannot think of a single reason of any consequence that would lead me to wire fuel pump(s) exclusively through the Master switch.  I see no plus side at all, and giving away so much flexibility and so many alternatives for no significant gain is IMO profoundly ill advised.  I'll have more than enough unanticipated problems without deliberately painting myself into a corner in the design stage.  Design is where I give myself all the flexibility I can.

Personally, I would want the capacity to alternate fuel pumps from day to day or flight to flight.  I would bias usage toward one just to keep wear uneven, but I don't like the idea of keeping one idle nearly all the time, and they draw enough current that I regard it as foolish to keep them both running all the time.  My inclination at this juncture is to use distinctive (and/or possibly guarded) switches for the fuel pumps and use one pump roughly twice as much as the other.

What compelling reason do you have for wiring it through the Master?  What does it buy you that you couldn't achieve better otherwise

What, precisely, IS your procedure for engine fire??.... Jim S.

Steve Brooks wrote:

Jim, 

Would you please elaborate about why you feel that the primary pump controlled only by the master switch is a very serious fire hazard ?

Cars don’t have a separate off switch for the fuel pump, and I don’t see allot of them burning along the highways.I would really like to know what the risks are.

Steve Brooks

-----Original Message-----
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of Jim Sower
Sent: Wednesday, March 17, 2004 11:40 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: mainfold hose

<... my primary pump runs as long as the master switch is on ...>
I would regard that as potentially a very serious fire hazard. 

<... was concerned about a main pump switch that could be accidentally turned off in flight ...>
I would be inclined to look at that concern as exaggerated if not totally bogus.  A switch on the panel cannot be turned off completely accidentally - you are deliberately turning something off, and if you hit the wrong switch, the engine will die so fast that you will still have your hand on the switch and can turn it back on immediately.  Additionally, how often are you manipulating panel switches at altitudes where a 1-second inadvertent shutdown would pose a problem?  If you are really REALLY afraid of inadvertent shutdown, how about using guarded switches on the hp pumps? 

I would NOT hard wire a pump through the master switch ... Jim S.