What the wings can carry

[Capn Notarious]

Could some one please explain to me without too much mathematics

How flight deck/planners/designers know how much weight wings will carry. A767 captain once told me that after a specified fuel burn, that a climb to a higher cruise level would occur.
I think we ascended from 35.000 to 37.500.
Now go easy with the answer, for I have borrowed an extra brain cell, and it needs to return in good order!:D

[747FOCAL]

Now I would never profess to being a loads engineer, but how it was explained to me was a "climbing cruise" as the plane burns fuel and reduces weight the plane climbs. The max weight the wings can lift from a certification point of view is at liftoff at see level standard day. In reality they will prolly hold more. But to ensure safety the manufacturers back it off a bit.

I don't think you could load a plane such that you get to a calculated vlof speed and snap the wings cause the plane is to heavy. That usually buys you the parking lot.

hope that helps.

[EyesToTheSkies]

Is a "climbing cruise" allowed, or is it a theoretical idea?

Obviously the more fuel the a/c burns, the higher it can climb, but presumably it must still conform to specific flight levels, and expedite a climb between them?

[Background Noise]

The amount the wings will carry depends on their design shape and their surface area. Once that is fixed, lift then depends on speed, angle of attack and air density.

As the aircraft climbs it gets to a level where it is at the optimum angle of attack and optimum speed (optimum engine rpm). As weight is reduced, less lift is required so speed can be maintained and AOA reduced or vice versa. Or the aircraft can be climbed until AOA/speed/rpm are optimum. Climbing is generally good because less fuel is used the higher you go.

Cruise climbs can be/are flight planned eg from this level at this point to new level at new point and they are flown. In practice the actual climb profile allowed will depend on traffic etc.

Or something like that (standing by for howls of derisive laughter)

[411A]

EyesToTheSkies.
Cruise climbs are nothing new.
In the 'old days' it was possible to get a clearance for a cruise climb in a DC-6B... did this many times OAK-HNL. Of course at that time there was not all that much traffic down low(er)...but not possible in jets later on.
Today certainly not possible due to traffic density.

[Avman]

I believe that once supersonic Concorde cruise climbs right up to TOD.

[RadarContact]

Then again, the Concorde does not have to worry about air traffic density a lot, once it's above FL430...