Posted for Rkexecutiveair@aol.com:

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