turbulence and windshear

[van der vart]

Is turbulence more a problem to smaller aircraft than bigger aircraft? what about windshear?
a medium aircraft, say 737, experienced moderate turbulence, would a 747 experience the same severity? what about windshear?

[TopBunk]

vdv

Firstly turbulence:

Turbulence affects aircraft as a function of wing loading more than anything else. An aircraft with a low wingloading will be more afffected than an aircraft with a high wingloading.

What is wingloading ... well, standing to be corrected, it is basically the aircraft mass divided by the wing area. In this respect, a heavier aircraft of the same type has a higher wing loading than a light aircraft of the same type, and hence rides turbulence better. As to between types, the 747-400 rides turbulence better than a 737 or an A320, which rides it better than an A319. I stress that this is not just because of total mass, but because of wing loading.

Secondly Windshear:

Windshear is a change of windspeed component (horizontal or vertical) over time. Lets say that you go from a 30kt headwind into a 30 tailwind over 0.5nm. That represents a 60kt loss of airspeed over 0.5nm. Now the slower your initial airspeed, the greater the percentage of your airspeed that represents. From that one can infer the slower the aircraft the greater the impplication. However in a prop vs a jet, a jet develops lift from thrust alone whereas a prop develops additional lift from prop wash over the wings, which helps substantially in the recovery.

As with most things in aviation, there is usually no simple easy answer.

[cjam]

Tidy work Top Bunk,

as far as the wing area goes, it includes the fuse area between the wings and any engine nacelles etc. ie. in a plan view of the a/c join the leading edges and trailing edges with straight lines and calculate the entire area.
Laters, cjam