Hi John, I have been following the this discussion and have a question.
My 1967 Alon A-2 was refitted with the 30 gallon system in 1995. I have examined the paperwork accompanying the STC for this system. On drawing 1A, I see only a crossover fuel line exiting the two tanks. Venting is left to the vented fuel caps. Is this system is "illegal" and/or dangerous? I have known this system was set up this way since acquiring the airplane 2.5 years ago. However, after reading what you and others have written, I am a bit concerned to say the very least! Read on... When I first joined this forum, I posted a question about this fuel system. After 1.5 years of flying the airplane, I noticed that fuel was being used only form the left fuel tank (this was not seen on previous local or cross country flights). Three different APs checked the fuel cap vents, all of the fuel lines, finger filters, fuel valve and drain valves found no blockages. After talking with Mike at Skysport, he sent me a couple of used vented fuel caps to compare to fuel caps on my airplane. The vents in the fuel caps on my airplane consisted of a transverse hole in the caps vertical ridge while the caps that Mike sent had vent holes in the leading edge of the caps. We added holes to the leading edge of my caps to match those Mike had sent and fuel began being used from both tanks (once again). After reading what William Bayne has written about a poor fitting fuel cap, I would like to replace the "rubber" fuel cap gaskets just to make sure I have a good seal on both sides. Does Skysport carry the rubber fuel cap gaskets? To date, I have only been able to find the cork gaskets. Thanks for your time and information! David N95CV --- In [email protected], John Cooper <j...@...> wrote: > > On 8/18/2010 2:00 PM, William R. Bayne wrote: > > The Ercoupe fuel system with unvented caps accepted by the CAA for use > > on a production aircraft under CAR 3 in the normal category, which > > vents wing tanks from the inboard end (well below the fuel level of > > full wing tanks), would have been excepted from your CAR 4a.606 rule > > by virtue of the engine being fed by gravity from the nose tank > > CAR 4a.606 only applys to tanks from which the engine can (directly) > draw fuel. The Ercoupe wing tanks are transfer tanks and do not fall > under the same rules. They are not critical to flight safety. A > temporary interruption in fuel flow from the wing tanks to the header > tank would likely go completely unnoticed (which begs the question of > whether and how often it happens...) > > When the header tank is removed then the regulations come into play and > the wing tanks move up to the critical list. Due to the wing dihedral, > there is no easy way to configure an effective vent line to connect the > air spaces of the two wing tanks, hence no easy way to meet the > regulations other than introducing a valve that prevents drawing fuel > from both tanks simultaneously. > > -- > John Cooper > Skyport East > www.skyportservices.net >
