From: "Marvin Kaye" <marv@lancaironline.net>
Subject: Re: Altitude Switch -- how's a guy to know?
To: lml
Date: Tue, 30 Jan 2007 14:16:32 -0500
Message-ID: <web-1799803@logan.com>
In-Reply-To: <122662.73341.qm@web34906.mail.mud.yahoo.com>
References: <122662.73341.qm@web34906.mail.mud.yahoo.com>
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Posted for bob mackey <n103md@yahoo.com>:

> The consensus for IO/TSIO 550's is that one should turn
   > the boost pump on to low at 10,000'...
   

> Also, the HPAT crew and other instructors seem to have 
   > settled on a standard for t/o (Low Boost - On) and for
   > changing fuel tanks (Low boost on, then off after tanks
   > are changed). We added those steps also.
   
   Maybe one of the engine experts could explain why a
   Continental TSIO-550 needs all this babysitting.
   Wouldn't it be easier and more reliable to use a
   pump that runs all the time along with a pressure
   regulator that delivers the same fuel pressure to
   the injection system all the time?
   
   If the fuel pump fails, a backup pump could be used.
   
   The excess fuel delivered to the pressure regulator
   could be returned to the tank, keeping the circulating
   fuel cool and avoiding vapor lock.
   
   Will the IO/TSIO-550 fail to run correctly if it receives
   fuel at the same pressure all the time?
   If so, then let's fix that design flaw so the pilot can
   focus on flying.
   
   -bob mackey