Mailing List lml@lancaironline.net Message #42649
From: Alan Adamson <aadamson@highrf.com>
Sender: <marv@lancaironline.net>
Subject: RE: [LML] Boost Pump
Date: Wed, 13 Jun 2007 02:56:06 -0400
To: <lml@lancaironline.net>
Like I said, I certainly wish there was more supportive data around to determine the best approach... I just offer some unqualified food for thot... Looks like I succeeded :)
 
Dennis, yes you are correct, I'm certainly not proposing any changes to the fuel system, just thinking outloud about the use of boost pumps.
 
BTW, if you want to keep a single switch  Eaton makes a DPDT 3 position switch with a manual lockable position on one side.  So it works as a toggle to the middle position and then to go to the 3rd position, you'd have to pull out on the lever and move it to the 3rd position and then it will be locked in that position until you pull the lever out.
 
This way, you could use OFF and Low boost on the toggle side, and if needed HIGH boost, locked if needed in an emergency.  That's what I was going to do until I went down the Vertical Power route.
 
Alan


From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Dennis Johnson
Sent: Tuesday, June 12, 2007 10:47 PM
To: lml@lancaironline.net
Subject: [LML] Boost Pump

boost pump is on low; the engine keeps idling.
 
According to Flying Magazine's September 2004 Aftermath column, a Bonanza with a TCM TSIO-520 crashed shortly after takeoff probably because the pilot inadvertently had the boost pump in the high position.  According to the article, full power operation with the boost pump on high would not cause an appreciable loss of power, but (according to the NTSB) when manifold pressure is reduced below 24 inches, the engine will quit.
 
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