What's up with this?
Jeez, I wish it were that simple. Simplified version:
Assumptions: Ship is trimmed to level flight at 100 knots TAS, and thrust is unchanged.
An instantaneous headwind component increase of +20 knots will produce an immediate increase in the ship's lift vector. Given constant thrust and no pilot inputs, the ship will pitch up, climb and deccelerate until it's TAS again equals 100 knots, at which point it will (after a series of Phugoid occillations) attain stable flight (TAS = to about 100 knots and GS = to about 80 knots), assuming no pitch control inputs from the pilot flying.
If the pilot flying desires to maintain altitude during the headwind event, he will apply nose down pitch to counter the increase in lift. This input will be translated into an increase in TAS and GS. The additional drag created by this scenario of increased airspeed will gradually slow the ship to its original TAS, and the resulting GS will be TAS - HW or about 80 knots, again, assuming thrust is unchanged.
In the tail-wind scenario, from stable cruise, an instantaneous tail-wind encounter will reduce the lift vector, causing the ship to pitch over and descend. TAS will drop to 80 knots and GS will gradually fall off. As the ship descends, it will accelerate, until reaching its trimmed speed, at which point, it will go through a series of Phugoid occillations until it again achieves stabilized, level flight (assumming no pilot inputs and a constant thrust.) At this point, TAS will be about 100 knots and GS will be about 120 knots.
Fly in any turb. (wind shear) and this is what you will experience.
Regards,
wlee