Username Protected wrote:
One quibble / I think fuselage lift contribution is closer to 20% of lift at cruise! Will double check though…
How did you all conclude that fuselage lift is a good thing? Every pound of lift that is generated by the fuselage is a pound that is not generated by the wings. Wings are more efficient at generating lift, and therefore generate less induced drag. 20% fuselage lift sounds like a more sellable way of saying “x% more induced drag.”
Are you sure that this is a feature and not a bug? Is is possible that the designers noticed “Ah %#$@, the fuselage is generating lift — and drag!” and then the marketing folks said “Oh, cool, the fuselage is helping!”
We do have to take pitching moment into account, of course, and it’s possible that the fuselage is offloading the forward wing and horizontal stabilizer, allowing them to be smaller, lighter, and less draggy, but in general, bluff bodies aren’t particularly good lifting bodies.
And no, the fact that the P180 is faster than other similarly sized and similarly powered airplanes is not proof that fuselage lift is good. Drag is a sum of many contributions, and speed is very engine and altitude dependent.
Mind you, I still want one
Your friendly neighborhood engineer,
Martín
