A flight instructor told me that the maneuvering speed of an airplane
decreases if you fly less than max gross weight. After some thought,
this seems wrong to me, and I’m interested in getting some opinions
and/or hard facts! :-)
Maneuvering speed is the top speed where the wings will stall before any
structural damage will occur if the wing suddenly is rotated to a high
angle of attack. Now, the maximum amount of lift the wings can generate
at a given speed is the same no matter what the gross weight of the
aircraft. And so, if the airplane is lighter, the wing lift can
accelerate the airplane up faster (f=ma), and hence the plane "pulls more
g’s".
I think this is the crux of the argument that you have to fly slower if
under max gross – you don’t want to "pull too many g’s".
The problem I have with this is that acceleration (g’s) don’t break
aircraft, force does. Think of an airplane as two masses – a
wing and a fuselage – with some kind of structure holding them together.
Then, if the you lighten the aircraft below max gross by making the
fuselage lighter, then the forces in the connecting structure are LESS when
wings generate maximum lift, even though you pull more g’s. (Details
available upon request).
By this reasoning, maneuvering speed ought to INCREASE if you fly less
than max gross. What’s the deal?
Regards,
Charles Bier
PP-Glider, Student- ASEL
posted by admin in Uncategorized and have
Comments (15)