I’ve seen online that a small group of designers have started the “KR-Super 2” design, however has anyone out there ever started a 4-seater KR design?
With the price of 4-seater airplanes these days being well into the 6-figure regime, I would think a KR4 would be a very popular design for those who just want an extra seat or two for the occasional passenger, or just a little extra luggage space. Most KR2S’s have an empty weight of around 600-700 lbs (mine is 650) with a Revmaster 2100 (65 HP), and a gross weight of approximately 1000-1200 lbs (mine is 1150 lbs). This offers fairly decent performance; not great, but not terrible either. If this “KR4” were to be powered by a 100 HP Continental O-200, in theory, to achieve the same Power/Weight ratio as the Revmaster, you could have a gross weight of approximately 1750 lbs. For a little factor of safety, let’s assume a Gross Weight of 1650 lbs. Of course when talking about a bigger airplane, you would need a bigger engine, a bigger structure, which means more weight. Base Empty Weight = 650 lbs Engine Increase (2100D to O-200) = +50 lbs Structural Increase (bigger airplane) = +250 lbs KR4 Empty Weight ~ 950 lbs Gross Weight = 1650 That leaves 700 lbs for fuel, passengers, and luggage. For a Continental 0-200, you could plan on about 6 gallons per hour, and could use 22 gallons for about 3 hours of endurance with a 30-45 minute reserve. This would leave you with 568 lbs for passengers/luggage. This would be plenty for two passengers and a lot of luggage, or three medium sized passengers and a small amount of luggage, or three larger (190 lb passengers) with no luggage. If you managed to get 100-110 knots with this setup you would have a range of about 300-330 NM. So what do you guys this? For those that have experience building, what limitations would there be with widening the structure, lengthening the fuselage, and also increasing the wing surface area? Would it be a matter of just building a stronger/thicker spar/wing, or is there more to this than I am realizing? I should have prefaced this with I am not an aircraft designer. Very Respectfully. Sam Spanovich N6399U 74S, Anacortes WA Sent from my iPhone ________________________________ -Please see LIST RULES and KRnet info at http://www.krnet.org/info.html -Change list delivery options at https://list.krnet.org/list/krnet.list.krnet.org/ Affinity List Info Board -Search recent KRnet Archives at https://list.krnet.org/empathy/list/krnet.list.krnet.org/ -Search John Bouyea's decades of archive at https://www.mail-archive.com/[email protected]/
