<p>Aerospace engineers should know what I’m taking about. You guys know how as a plane speeds up, the air above the wing decreases in pressure because of the speed and that causes lift? Well in a jet fighter…doesn’t the enormous thrust of the engine push the airplane up also when the angle of attack is really high? I’m going to use a rocket’s thrust as an analogy, Bernoulli’s principle doesn’t apply there. In this case, do I include both upward forces?</p>
<p>Sure the downward component of the engine’s thrust will provide a small contribution to the “lift” on the plane but it will be absolutely tiny compared to the overall action of the wing.</p>
<p>But once the plane points higher than its critical angle don’t the wings lose their effectiveness and actually add resistance?</p>
<p>You should include both - but, no matter how awesome a modern jet engine is, it won’t be able to sustain straight up vertical flight for long. In either case you always trade altitude for speed…</p>
<p>Sure if it points high enough then the wing will lose lift. Then it will fall out of the sky.</p>
<p>You get lift from three things: shape of the airfoil relative to velocity, angle of attack, and orientation of the engine(s). All three are influenced by the orientation of the aircraft, so there will be angles where one or more are reduced to zero or even become negative. The trick to piloting is avoiding these angles for any real length of time.</p>
<p>And there is always resistance from the wings, again dependent in part on the shape and angle of attack. Balancing these considerations is the principal concern of the field of aerospace engineering.</p>