I think you are confusing jetstreams with windshear. Jetstream winds don't change so suddenly, and the wind component change does not cause problems- however the turbulence usually associated with the component change can. Encounters with windshear tend to happen closer to the ground where flaps and undercarriage may be deployed and the aircraft may not be in a good position to climb away. On final aproach, they tend to be obvious- the aeroplane may be in a peculiar attitude with the thrust levers far forward or backwards, and speed may still be running away. It should be obvious something is wrong. A bad encounter can be unrecoverable. But, during an encounter with the speed increasing and the thrust levers almost closed, better not to over-react and close them completely- you know that suddenly it will all change and the speed will be falling, your engines will be at idle and slow to accelerate, and you may be very embarrassed. Best not to chase the speed too aggressively trying to increase or reduce for when it will all change. Sorry if this is a bit cryptic, but it is a very complicated area.
In plain old turbulence, you just fight to keep the speed approximately right without overdoing thrust changes. Like the windshear feature, you know if it is increasing now,it will soon be decreasing- so don't get caught with slowly responding engines at the wrong speed.
Last edited by Notso Fantastic; 17th Jan 2003 at 18:46.