X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 12 Oct 2007 20:00:03 -0400 Message-ID: X-Original-Return-Path: Received: from imo-m14.mx.aol.com ([64.12.138.204] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTP id 2382527 for lml@lancaironline.net; Thu, 11 Oct 2007 22:59:13 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.138.204; envelope-from=Sky2high@aol.com Received: from Sky2high@aol.com by imo-m14.mx.aol.com (mail_out_v38_r9.3.) id q.bc8.1b473828 (42809) for ; Thu, 11 Oct 2007 22:58:32 -0400 (EDT) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Thu, 11 Oct 2007 22:58:32 EDT Subject: Re: [LML] Fuel transfer problem on Lancair 320 X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-----------------------------1192157912" X-Mailer: AOL 9.0 VR sub 165 X-Spam-Flag: NO -------------------------------1192157912 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 10/11/2007 8:34:01 P.M. Central Daylight Time, james.gigliotti@us.army.mil writes: I have a Lancair 320 that transfers fuel from the wings to the header tank, which has the typical sight tube to verify header quantity. Level switches in the header tank typically turn the transfer pumps on as header fuel drops below approximately 5 gallons, and off as the fuel rises to around 8 gallons in the header. On a long cross country flight last weekend I was distressed to observe one cycle where the pumps weren't turned on untill 3 gallons, and another cycle where they didn't turn on until 2.5 gallons. Each time they turned off at only approximately 4.5 gallons. That made me nervous, so I began manually transferring. I wanted to fill the header to around 10 gallons, however I could only get 8 gallons into the header (according to the sight tube). I figured something was wrong with my pumps, and that perhaps they were only transferring as fast as I was burning fuel. As I was considering looking for a place to land (after about 20 minutes of transferring), I observed first my right wing, and then shortly thereafter my left wing ran out of fuel, about 2 hours early. I figure I must have pumped 14 gallons overboard somehow, since I topped off prior to the flight and had ample fuel to complete the flight. 1. Can anyone offer suggestions as to why my transfers are beginning at lower values suddenly? 2. Does anyone have any thoughts as to how I could transfer fuel overboard, even though my header read at max 8 gallons? (Later, on the ground, I pumped the header up to 12 gallons without venting any fuel overboard.) 3. Can anyone point me to a better system, perhaps with a real gage, and a more reliable (accurate) system for automatically transferring fuel? Jim, If your engine was burning 10 GPH, that is 1/6 GPM or about .17 GPM. One of my Facet pumps moves about .8 GPM from a wing into the header. Since I usually run both at the same time, that is about 1.6 GPM to the header where the engine is only using .17 GPM at cruise. I can only suspect that your sight gauge was misleading you. If you were switching single pumps between wings for 20 minutes and the header became full, I can certainly see where you could have pumped 14 gallons overboard. Do you remember the sight gauge reading before your descent to land and then what it read on the ground - If so, how many gallons difference was seen (those not accounted for by the aircraft no longer being level)? Is it possible that something has changed in the venting for the header? Something blocking the sight tube? Some crazy air bubble that wouldn't clear up till you were on the ground? What kind of level switches are you using? How did you know your wings were going empty? Scott Krueger AKA Grayhawk Lancair N92EX IO320 SB 89/96 Aurora, IL (KARR) Darwinian culling phrase: Watch This! ************************************** See what's new at http://www.aol.com -------------------------------1192157912 Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: quoted-printable
In a message dated 10/11/2007 8:34:01 P.M. Central Daylight Time,=20 james.gigliotti@us.army.mil writes:
<= FONT=20 style=3D"BACKGROUND-COLOR: transparent" face=3DArial color=3D#000000 size= =3D2>

I have a Lancair 320 that transfers fuel fr= om the=20 wings to the header tank, which has the typical sight tube to verify heade= r=20 quantity.  Level switches in the header tank typically turn the trans= fer=20 pumps on as header fuel drops below approximately 5 gallons, and off as th= e=20 fuel rises to around 8 gallons in the header.

On a long cross country flight last weekend= I was=20 distressed to observe one cycle where the pumps weren't turned on untill 3= =20 gallons, and another cycle where they didn't turn on until 2.5 gallons.&nb= sp;=20 Each time they turned off at only approximately 4.5 gallons.  That ma= de=20 me nervous, so I began manually transferring.  I wanted to fill the=20 header to around 10 gallons, however I could only get 8 gallons into the=20 header (according to the sight tube).  I figured something was wrong=20= with=20 my pumps, and that perhaps they were only transferring as fast as I was=20 burning fuel.  As I was considering looking for a place to land (afte= r=20 about 20 minutes of transferring), I observed first my right wing, and the= n=20 shortly thereafter my left wing ran out of fuel, about 2 hours early. = ; I=20 figure I must have pumped 14 gallons overboard somehow, since I topped off= =20 prior to the flight and had ample fuel to complete the flight.

1.  Can anyone offer suggestions as to= why my=20 transfers are beginning at lower values suddenly?
2.  Does anyone have any thoughts as to how I could transfer= fuel=20 overboard, even though my header read at max 8 gallons? (Later, on the gro= und,=20 I pumped the header up to 12 gallons without venting any fuel=20 overboard.)

3.  Can anyone point me to a better sy= stem,=20 perhaps with a real gage, and a more reliable (accurate) system for=20 automatically transferring fuel?

Jim,
 
If your engine was burning 10 GPH, that is 1/6 GPM or about .17 GPM.&nb= sp;=20 One of my Facet pumps moves about .8 GPM from a wing into the header. =20 Since I usually run both at the same time, that is about 1.6 GPM to the head= er=20 where the engine is only using .17 GPM at cruise.  I can only suspect t= hat=20 your sight gauge was misleading you.  If you were switching single=20 pumps between wings for 20 minutes and the header became full, I can=20 certainly see where you could have pumped 14 gallons overboard. 
 
Do you remember the sight gauge reading before your descent to land and= =20 then what it read on the ground - If so, how many gallons difference was see= n=20 (those not accounted for by the aircraft no longer being level)?  Is it= =20 possible that something has changed in the venting for the header? Something= =20 blocking the sight tube?  Some crazy air bubble that wouldn't clear up=20= till=20 you were on the ground?
 
What kind of level switches are you using?  How did you know your=20 wings were going empty? =20
 
Scott Krueger=20 AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL=20 (KARR)

Darwinian culling phrase: Watch=20 This!



= See what's new at = AOL.com and Make AOL Your Homepage.
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