Did I miss something about the
accident? I thought it happened within a few minutes of departure? If this
is the case, and the belly tank was used for fuel, it could never have been
pumped off by the time of the accident anyway. All current systems I am
aware of that pump belly tank fuel to the wings, do so pumping at the same
rate as the normal fuel flow to the engine. Thus under normal operations,
the belly tank will not be emptied for well over an hour into the
flight.
Like many turbine builders, I have
studied and tolled over the best system for safety, reliability, and
simplicity. My system is not much different than standard, but I have
incorporated some of the safety features Joe T. is using. I am not
convinced the belly tank is significantly safer empty
than it is full, at least not enough to warrant more complexity to the fuel
system and fuel management. I have tried to consider what are the
most likely factors that contribute to an accident, and risk goes up with
complexity. I believe this has been the case in some previous Lancair
accidents (complexity). I have worked with some Cessna Caravan techs
and verified our system next to this certified system. The Caravan uses a
belly tank as the main fuel supply, but admittedly, fixed gear reduces
belly impact considerably.
I am concerned that anyone blame
"systems" or "designs" for problems they have not created. If you
take issue with a design, state your concern. We all can benefit from
thoughtful exchange, especially with the tremendous resources we have within our
Lancair community.
Tom Sullivan
IVPT
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