I think there's a reason you only see one Vans model that's a 4-seater. Not a big market and there are plenty of 4 seat options out there already. IMO a 4 seater KR would be a waste of someones time unless you just like building one off airplanes.
CRaig N886MJ (N51CW) N6423B > On 12/12/2021 2:51 AM Samuel Spanovich <spanovich...@gmail.com> wrote: > > > 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/krnet@list.krnet.org/ ________________________________ -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/krnet@list.krnet.org/
