Researching Lights and Pitot Tube Placement

After receiving my new Dynon Heated Pitot Tube I started researching the placement of the pitot  tube in the wing, and looked at several builder sites to see exactly where they placed the pitot tube, and how they routed the airlines and electrical wiring for the heat controller. As I was doing this, I had a revelation of sorts that kind of concerned me just a bit. The reason is that it seems that most builders using the same components that I am using are locating their pitot tubes in the bay just OUTSIDE of the location that Vans uses for the stock pitot tube. The reason is that the location for Van's stock tube is in the same bay where the aileron push/pull tubes and the aileron belcrank are located, not to mention a possible autopilot servo and all the associated wiring that goes with it.


In short, this is a very busy and critically important bay in the wing that houses some of the most critcal flight components of the aircraft. So anything that may interfere with those components is a serious potential hazard. The stock pitot from Vans works in this location because it is nothing more than a length of 1/4 inch aluminum tubing bent to shape and mounted through a hole in the bottom main wing spar flange, and then routed through the holes in the main wing ribs back to the fuselage. It is mounted to the bottom spar flange so it is out of the way of the push/pull tubes and the belcrank. Unfortunately, a pitot tube such as the one I am planning to use will have to be mounted in such a way that placing it in this same bay could cause several different problems, none of which I am willing to expose myself or my eventual passengers to.



The general thought is to move the pitot further out on the wing to ensure that airflow from the fuselage does not introduce airspeed indication errors due to disruptions caused by the fuselage or the landing gear, etc.

All that said, positioning the pitot tube further outboard under the wing also creates a new problem. The problem can occur when the time comes to tie down the aircraft at your destination airport, either for a fuel stop or as you final destination. To do this, you have to rely on the tie down spots that have been positioned by each airport's FBO. The placement of these tie downs is up to the discretion of the airport operator, and is usually based on the types and even the makes and models of aircraft most frequented at the airport.



As I reviewed the plans, I started to realize that if I move the pitot tube to the next bay outward, there is a risk of a tie down rope coming into contact with the pitot tube. This is because the ties down ring will end up being inside of the pitot tube. I submitted a post to VAF to ask for photos from folks with a similar installation that shows the positioning of a typical tie down rope and the pitot tube after the airplane is tied down. What I found is that there is definitely a possibility of the rope interfering with the pitot tube and damaging it or even a part of the wing in the process, unless the wing tie down rope is positioned slightly forward. This may or may not be possible from one airport to another, and depends on several factors, such as position of the tie downs on the airport in relation to each wing tie down ring on the RV, and the position of the tail tie down point. The pictures sent to me in the VAF post pretty much tell the tale.



So, now the question is, what to do about this, if anything. Luckily today I think I arrived at a solution, while not perfect, is good enough for me and is one that I will implement when the airplane is ready to travel. Basically, what needs to be done is to find a way to extend the tie down ring a little bit more, so that the ring is just a bit lower than the lowest point on the pitot tube. The tie down rings are simply standard 3/8 inch eye bolts thatr are usually 2 inches in length. I googled for eye bolts to see if I could find some with longer shaft lengths that the typical 2 inch long ones at the local HD airplane store.


As luck would have, the first link in the search results returned a company that deals in exactly that, all sorts of different sizes and configurations of all types of different eye bolt applications. Therefore, my plan will be to carry these slightly longer eyebolt extensions with me on the plane, and any time I have to tie down at an airport where I have to be concerned about the clearance of the tie down rope or chain with the  pitot tube, I will just insert the longer eye bolts, and the problem should be solved.

Now I can proceed with installing the pitot tube in the outer bay without worrying about the tie down problems.



I have also spent some time reviewing lighting solutions. Duckworks has a lot of my attention right now, in addition to Aveo and AeroLED. I am starting to wane from any interest in AeroLED because they appear to be posturing themselves as a bonafied certified aircraft shop, with the experimental market as an after thought. Unfortunately the prices for their LED light solutions are also representative of that situation, and I am far from interested in spending 2000.00 + for a stupid outside light solution for this airplane. That is just absolutely absurd and rediculous, and anyone that pays that kind of money for something like that ought to be ashamed IMHO. I'll have more on the lights later on.