Hi all,
I am following this post - and previous discussions on fuel flow sensors and
fuel
computers- with amusement as it seems to me that all this high tech stuff needs
a lot of attention and may be less reliable than the old fashioned equipment
they want to replace. It is true that float type fuel gauges in the typical
wing fuel tank are not accurate nor reliable. This is mainly due to the flat
shape of the tank were a small height error makes a big volume error. I remember
when flying Cessnas the gauges were only rough indicators that there were
some fuel on board, and were useless in flight as they were looking like
windshield
wipers at the lightest turbulence. The Europa fuel tank geometry, being
all in height, makes it a lot easier to accurately gauge the fuel quantity.
My aircraft was originally fitted with an Avelec capacitive gauge with a digital
indicator. It was giving a false sense of a great accuracy due to the digital
display, but the indication was varying with the type of fuel used. After about
200 hours it started to give random indications and finally failed completely.
I decided to replace it with an old fashioned resistive, float type with
an analog indicator. This Jaeger unit is used on Robin DR400 type certificated
aircraft. I had to weld an extension to the oscillating arm to take into account
the unusual height of the tank. The fuel quantity accuracy and repeatability
are very good. They are not visibly affected by the attitude of the aircraft
and when refueling I can predict the quantity to be added to top the tank by
a few liters. Additionally there is a low fuel switch integrated into the probe
system which illuminates a warning light when the fuel remaining is 1.5 liters.
Then I know I had better to switch to the reserve side. My back up is my
watch: flight time and a conservative calculation using the maximum cruise fuel
flow. This system has been working fine for me for 10 years and 800 hours.....
without any fancy electronic chip, computers etc...
Remi Guerner
F-PGKL
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