Wing Bending Relief
In fixed-wing aircraft, fuel is usually carried in the wings. Weight in the wings does not contribute as significantly to the bending moment in the wing as does weight in the fuselage. This is because the lift on the wings and the weight of the fuselage bend the wing tips upwards and the wing roots downwards; but the weight of the wing, including the weight of fuel in the wing, bend the wing tips downwards, providing relief to the bending effect on the wing.
When an airplane is being loaded, the capacity for extra weight in the wing is greater than the capacity for extra weight in the fuselage. Designers of airplanes can optimise the maximum takeoff weight and prevent overloading in the fuselage by specifying a MZFW. This is usually done for large airplanes.
Most small airplanes do not have a MZFW specified among their limitations. For these airplanes, the loading case that must be considered when determining the maximum takeoff weight is the airplane with zero fuel and all disposable load in the fuselage. With zero fuel in the wing the only wing bending relief is due to the weight of the wing.
Read more about this topic: Zero-fuel Weight
Famous quotes containing the words wing, bending and/or relief:
“No Raven’s wing can stretch the flight so far
As the torn bandrols of Napoleon’s war.
Choose then your climate, fix your best abode,
He’ll make you deserts and he’ll bring you blood.
How could you fear a dearth? have not mankind,
Tho slain by millions, millions left behind?
Has not conscription still the power to weild
Her annual faulchion o’er the human field?
A faithful harvester!”
—Joel Barlow (1754–1812)
“No ray is dimmed, no atom worn,
My oldest force is good as new,
And the fresh rose on yonder thorn
Gives back the bending heavens in dew.”
—Ralph Waldo Emerson (1803–1882)
“Across Parker Avenue from the fort is the Site of the Old Gallows, where 83 men “stood on nothin’, a-lookin’ up a rope.” The platform had a trap wide enought to “accommodate” 12 men, but half that number was the highest ever reached. On two occasions six miscreants were executed. There were several groups of five, some quartets and trios.”
—Administration in the State of Arka, U.S. public relief program. Arkansas: A Guide to the State (The WPA Guide to Arkansas)