In Britain, we build the KR using blue Styrofoam as it is better, being stronger and more resilient to compression fractures and delaminations from the glass skin. Trouble is, fuel melts the Styrofoam, so we can't have fuel in the wings in any way, as a fuel leak would lead to failure of the wing.
So we just use 20 gallon fuel tanks above your feet, don't bother with wing tanks at all. Doing this means you don't need fuel pumps or fuel valves or pipes or fuel cocks, all extra weight, we don't need fuel gauges that are unreliable, so we know with sight gauges accurately exactly how much fuel is onboard. We make aluminium tanks that are bolted in under the front cover, so you can remove the front cover and the fuel tank to get to the ruder pedals and brake master cylinders easily for service or repair. 20 US gallons gives me 4 hours with a 30 minute reserve with my Jabiru engine, that will get me from home to well into Europe, none stop. As for C of G, the tank is forward of the C of G, so as the fuel burns the C of G moves further back, but not really an issue, even with the 6 inch C of G range we use here. My Kr2 becomes neutrally stable at 6 inches, the last 2 inches of the books 8 inch range and any further back there is no stability, indeed it becomes divergent. But even with the 120lb Jabiru engine being so light on the front, we have to move the engine forward on a long engine frame and then to enable maximum cockpit load, the empty C of G with a full tank means that we had to move the main wheels 2 inches further forward to place enough weight back on the tail wheel to be able to get out the plane and not worry about it being blown over by some other idiot pilot and his prop wash. So before any more thought on wing tanks, ask yourself, why and do I really need them? Someone said, they are not a fan of fuel in the cockpit, but having it there, you certainly know if it is leaking. Fuel in the wings could leak out, you have no real idea how much is in there anyway and a fuel leak in the wing, shouldn't damage the Eurothane to epoxy wing skin resin bond or damage the spruce when it soaks into it that much, but it is not a risk worth taking. If you have a leak in the tank in the fuselage, which would be very rare of course anyway, but at least you can smell it straight away, before it does any damage. A leak in a wing tank could be damaging your wing for weeks months years before you found out. So personally, I didn't want wing tanks. When I flew for 10 hours and 1,050 nautical miles through Russia, I had an Auxiliary tank on the passenger seat. CH. _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
