The boost pump issue at altitude is only one of fuel vaporization, generally due to rapid climbs to the flight levels where the vapor pressure of warm fuel is causing bubbles to form in the fuel.  A slow climb, allowing the fuel to cool off or the addition of the boost pump to stop the vaporization is the answer.  I generally leave the boost pump on in cruise for about 30 minutes, allowing the fuel in the tanks to cool off.  Once this is achieved, there are no more vapor problems.

Walter


On May 8, 2007, at 8:34 PM, Kevin Stallard wrote:

Has anyone been able to do something to mitigate this requirement of
having to have the boost pump on at altitude?

I've had some ideas put in my head by a good friend of mine like: What
is the good of having mags or anything else that makes an engine run
without the battery if it's just going to have a fuel starvation problem
when the lights go out...

I'll continue to look through those posts, but I'm not finding anything
that would speak to this directly.

Thanks
Kevin

--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html