Mailing List lml@lancaironline.net Message #10154
From: George Braly <gwbraly@gami.com>
Subject: RE: Unusable Fuel
Date: Tue, 26 Jun 2001 01:47:06 -0500
To: 'lancair.list@olsusa.com' <lancair.list@olsusa.com>
         <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
>>
The "full fuel" comment was only for emphasis that you don't want two empty
tanks.  The trim problem is not an issue for routine operations as one need
not unbalance the aircraft a significant amount in order to do this exercise
safely.

If the engine does not start *IMMEDIATELY* by merely switching from one dry
tank to one "adequate" tank, then something is simply wrong with the fuel
system design or installation.  

It should take no more than 2 to 5 seconds maximum, without the boost pump,
if you wait for the engine to completely die from starvation on the tank
going dry.  If you switch tanks at the first sign of fuel starvation (fuel
flow fluctuation) then the engine will hardly miss a beat.

If you are truly fearful of this exercise, then get somebody to do it with
you that understands the system and knows and appreciates why it is
important.

I and many, many other experienced pilots do this rather routinely in a
great variety of aircraft in order to verify  *USEABLE* fuel capacity.

Simply running the tank dry on the ground is not sufficient information.
The in-flight attitude of the aircraft is different than the ground
attitude.  Further, one needs to explore the effects of pointing the nose UP
or DOWN a few degrees with only one or two gallons left in a tank (one at a
time, please).

Hey... folks, you are building experimental aircraft.  They are all
different.  It is, in my opinion, imprudent to fail to accomplish these
simple and definitive "exercises" to make sure one understands the capacity
of the system under all conditions.   It is a lot better to do this under
controlled conditions than to be surprised at the result 3 miles short of
Flagstaff's runway.

Regards,  George



-----Original Message-----
From: Marvin Kaye [mailto:74740.231@compuserve.com]
Sent: Monday, June 25, 2001 7:28 PM
To: Lancair Mail List
Subject: Re: Unusable Fuel


          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
>>
This is a reply to George Braly's post on Useable Fuel as submitted by Bill
Hogarty <billhogarty@aol.com>:

George:

Read your post on the Lancair list.  Wanted to caution you about your
suggestion "  to run one tank dry with the other hopefully full"
<SNIP>
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster