Hello folks,
Once again I find myself needing your help.
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?
Thanks very much,
Jim.
LNC2 N91LS,
approximately 310 hrs.
KEDN
James M.
Gigliotti
Support Contractor (Camber)
Concepts & Requirements
Directorate
Requirements Division, AGSE
Fort Rucker, AL 36322
Commercial
(334) 255-1459
DSN 558, FAX 1008