Diagram of the fuel system layout (provided by Tony Jurcan)
This page consists of a description of the fuel system installed in the most recent Seawinds to come out of Bowes Aviation.
A review of the ISPA incident log, just as a review of most aircraft incident logs, shows that a high percentage of aviation incidents stem from fuel system problems and anomalies. For this reason, SNA (the manufacturer of the Seawind and Seawind kits) has understandably been outspoken about builders making any changes to the factory designed Seawind fuel system. Please, any modification to the fuel system must be done with a thorough review by the experts. Installation of the system shown here must be done with close coordination and review by Bowes aviation.
Bowes Aviation and the ISPA are providing this page not as a recommendation, but for information only, and are not liable for it's use.
The ISPA thanks Mike Bowes for the text on this page, and Tony Jurcan for the sketch.
Dual header tanks shown above next to the MLG retract arms for size comparison.
As many of you now know, N369JB has a dual header tank fuel system that feeds into an Andair Left, Both, Right, Off fuel selector valve. Fuel then passes through a stainless mesh fuel filter and then through an electric boost pump on its way to the engine's mechanical pump.
The following update was added by Mike Bowes in post #917 on October 20, 2003:
Boy is my face red! I mean crimson. The ranting and raving I've been doing about how this valve will not pass fuel from one side to the other when selected to "BOTH". Not correct, sorry to say.
Guys, I am so sorry, this was the impression I had formed from observing my own airplane over the past 18 months. I guess Seawind N369JB has been parked consistently on flatter ground than I realized.
We had a lively debate in the shop today, concerning what built-in design features the valve must incorporate so as not to allow transfer of avgas from a high tank over to the low tank when selected to "BOTH". The final consensus was there must be built-in check valves...it was the only thing we could imagine that could produce this effect. Wrong!
I called merry old England and talked to Andy Phillips, at Andair, directly, late in his day over there. After explaining the nature of our debate, he laughed and, like a true diplomat, said we could all be right. The valve will not pass fuel from one side to the other only if it is selected to any other position but "BOTH". Unfortunately, he explained, it will in fact pass fuel from high to low if left in the "BOTH" position and parked on uneven ground, or when left sitting in the water with one wing low.
Therefore, I very much stand corrected and you just may want to install those big red check valves after all. Especially if you know you can't remember to move the valve position out of "BOTH" as you exit the airplane at the end of the day.
Myself, I will not install them at this point. I have found the system entirely adequate and much to my liking over the past 180 hours. Mike, humble pie eater, N369JB
The following photo and text was added April 24, 2004: Mike Bowes has sent us the photo at the lower right showing ISPA member Dick Wolf's dual fuel pump installation. One of Mike's dual header tanks can be seen along the left side of the photo.
Mike also provides the following text: "As always, a picture is worth a few hundred words, and this view of the Airflow Performance dual fuel pump and filter installation in a seawind is pretty much self-explanatory. The location is right side of the tail-cone with the right side of the photo being direction aft.
The incoming fuel line (coming from the Andair selector valve) rises up from under floor in lower left of photo. The outgoing, 25 psi line (going to the engine) is in the upper right corner. Incoming fuel hits the cleanable filter first, a good thing, and then on to the pumps. Fuel regulator bypass pressure is routed back to the incoming line ahead of the filter by means of a "T" fitting inserted in the vertical incoming line. Note there is a reducer bushing that changes the 3/8" pressure bypass line to 1/2" tubing immediately before the "T".
This is an example of one man's solution to the installation challenge. By all means, if you can improve on this, do so. It's a neat, compact, installation using sweeping curves of tubing and thereby eliminating a great number of additional fittings which might otherwise have been used. All components are easily visible and accessible for leak-checking and service, from time to time. Right site, left side of tail-cone doesn't really matter. You choose where you want to put it.
Hope this helps those of you who have decided to build in this equipment."
Mike, chief fuel plumbing guy, N369JB