Mr. McDonald,
Having read your previous posts on this forum concerning this
subject I cannot help but wonder as to your motives. Why keep questioning the
design of this very simple, straight forward and reliable design.
I have considerable personal experience with this series aircraft
and have been involved in the construction, flight testing, and operation of
several Propjets using both certified Walter 601 E and aftermarket D model
engines. As you state they are normally very reliable when operated and
maintained correctly, more on that later.
I know of no Propjet engine failures to date that can be
attributed to the basic design of the Lancair fuel system, and would much
appreciate if you could enlighten us on this if you have any pertinent
information. As you are aware, these are EXPERIMENTAL AIRPLANES and
as such are subject to all kinds of well intentioned modifications such
as the system of pumps and valves used to feed the wing tanks from the
belly tank, which in my humble opinion only introduces more failure points,
weight, and increases pilot work load.
Airplanes crash for all kinds of reasons, sometimes they burn,
I myself witnessed a Piper PA 32 Lance that crashed on landing and burned
to ashes, no belly tank on that airplane. I have lost a friend and customer to
flight into a thunderstorm in Canada, another died when the wing came off a
Turbine Aero Commander last year in Oklahoma. His IV-PT flew great.
Every crash involving the IV-PT airplane that I am aware of has been
attributed to reasons other than the design of the fuel
system.
The vent valve as installed by the factory system to vent the belly
tank during filling is as foolproof as it can be, I have had many conversations
with other builders and the people involved with designing and testing of this,
and I can tell you that if the valve were to fail in flight no detrimental
effects would result. It would merely provide an additional source of
atmospheric venting if the vent port was shaped and oriented correctly, if not,
the worse case would be a slight loss of fuel due to siphoning. The engine will
not stop. If the fuel system is built to plans the engine will be able to
consume all but a few gallons of unusable fuel. as far as landing on the belly
tank, that is what the LANDING GEAR is for.
In this last crash in Texas, I have personal information the leads
me to believe that the engine was damaged due to previous overtemp operations.
Any engine will fail if not maintained and operated properly.
Again, I am not sure why you keep trying to debate this issue, I can
only assume that your comments are well intentioned and are offered in the
spirit of safety and concern for the well being of all involved in the
experimental aircraft community, which is what this forum was originally created
for in the first place. If you have any constructive comments to make in the
future I am sure we will all be appreciative, otherwise please keep
your uninformed and alarmist opinions to a minimum.
Richard L.
Kidder