As speed increases, pitch excursions become harder to manage. One reason is obvious: Aerodynamic forces upon control surfaces increase, but the strength of the pilot does not. Another reason is subtler, and has to do with the behavior of lift coefficient. Lift coefficient is the ratio between the lifting force produced by a wing and the force of air, at the same speed, against a flat surface. The weight of the airplane being constant, the faster it goes the lower its lift coefficient. At very high speed an airplane might have a lift coefficient of, say, 0.1 — one 10th. Lift coefficient increases at a constant rate with angle of attack. That rate varies from wing to wing, mainly as a function of aspect ratio, but for the sake of discussion let’s say that it increases by 0.1 per degree. If an airplane’s lift coefficient is 0.1 in level flight, then all that is needed to generate 2 Gs is to increase the angle of attack by one degree. At a lower speed, however, say the speed for best rate of climb, it might take six degrees’ change of angle of attack to double the G loading. That same six-degree pitch change, occurring at high speed, would generate six Gs.