Hi all, I was re-reading all the messages involving the venting issue, and I wonder if any of you could send a detailed photograph of the air vent of the fuselage tank. And one more question just to see if I understood: The fuselage tank has always an air vent (in all models), no matter if a fuel gauge is present. Is that true ? Thank you very much ! Daniel Arditi Buenos Aires, Argentina
________________________________ From: William R. Bayne <[email protected]> To: ercoupe-tech list' <[email protected]> Sent: Wednesday, April 8, 2009 8:03:47 PM Subject: Re: [ercoupe-tech] Fuel Tank Plumbing & Caps Actually, it's 4423 (the last 415-C). The FAA-approved Flight Manual for the E and G Models states, on p.. 8 (with reference to wing tank caps), "do not use caps with vents in this model Ercoupe. The fuel schematic on p. 7 is functionally identical to that shown in the FAA-approved Flight Manual for the D Model on p. 7.. 415-D and 415-CD airframes are identical in every respect excepting only the allowed elevator movement and allowable gross weight. Accordingly, the fuel system schematic for the 415-D model is also applicable to the later 415-CD Model; although there is NO FAA-approved Flight Manual for the model 415-CD. Because of widespread replacement of the terneplate tanks originally fitted to Ercoupes through serial number 2622 with ones of differing capacities and configuration constructed of either stainless steel or aluminum, and Erco's decision not to stock replacement lines for any but the latest production configuration of the various production schematics (see Ercoupe Parts Manual and Ercoupe Service Memorandums 39 and 43), and factory "updates" of unsold 415-C airframes to the later 415-CD model, there are almost as many Ercoupe plumbing variations today in the field as there are Ercoupes. Serial numbers are NOT a reliable way to determine whether a given Ercoupe should have vented or unvented wing caps. There are serial number glitches throughout the Parts Manual and Bulletins and Memoranda. We all have abstract doubts, but few of these can survive the determined application of diligent and competent scrutiny. You need to properly understand how YOUR fuel system functions. If your Ercoupe has a separate overflow line feeding into each wing tank (i.e. it conforms to the fuel schematic installed in the 415-D, CD, E and G models and each wing tank vents to the header tank), it "vents" to the header tank via the overflow lines and SHOULD NOT have vented wing tank caps. With a good seal between each such tank and its unvented wing tank cap, the problem of fuel "venting" out of filled wing tanks when departing cross country is eliminated...an advantage well worth installing the tee and additional overflow to the other wing tank (in my humble opinion). I want every ounce of fuel my wing tanks will hold available for cross-country use, and do not view regularly venting out (wasting) upwards of a gallon (per leg) as acceptable (not that this is typical of vented wing tanks, but also not exactly uncommon). If unvented caps are installed on a plane that should not have them, the "penalty for being wrong" is no different than if a bug blocks the forward-facing vent of one of two tanks fitted with vented caps. If the cap blocked is on the tank with the overflow line, said tank continues to vent to the header tank through it (i.e. would not be affected). If it is on the other tank, erratic fuel readings might result, and some of the fuel from the unvented tank might be unusable. Such an in-flight occurrence should NOT create an emergency situation for any but the most obtuse pilot. Best regards, William R. Bayne .____|-(ø)-|____. (Copyright 2009) -- On Apr 8, 2009, at 11:54, John Cooper wrote: > The cutoff for the vented caps on the wings is sn 4424. Reference the > Ercoupe parts catalog. > > Due to the way things have been swapped around over the years, I’d be > absolutely certain the fuel system you have matches the configuration from > the factory before switching to unvented caps. The penalty for being wrong > is much more severe than if you put vented caps on a system that doesn’t need > them. > > John Cooper > Skyport Services > www.skyportservices.net
