ORIGINAL: H.Dale
I'm not sure why the analogy of a bicycle being on the ground makes a difference. If an airplane requires 30 mph of wind flowing over the wings to keep it in the air and an abrupt tail wind causes that to drop below 30 then how does it stay in the air? The wind shear in the L-1011 crash was just that, an abrupt change in wind speed from what I remember.
U are assuming that a 180 degree turn causes ANY shift in the wind felt by the plane. It doesn't.
I know that it's counter-intuitive, but it just doesn't.
In the case of the L-1011, wind basically exploded behind the plane faster than the co-pilot could react. (It was survivable had he reacted sooner and smarter. After the crash, that became an industry case study so that we could all learn from others' sacrifices, and many of us trained in sims loaded with the data from their flight recorder)
Flying circles in a steady state wind is to swimming circles in a flowing river, as flying in a windshear is to swimming circles in a still river next to the dam as it bursts.
In the former you will feel nothing, in the latter ur gonna swallow some water !