You are on steady climb at 1000fpm, you then pitch up to 2000fpm. The vertical component of lift

• A. Decreases
• B. Increases
• C. Stays the same
• D. Reverses

Answer: (A)

When you pitch up to climb faster, the flight-path angle increases. Lift acts perpendicular to the relative wind, so as the airplane’s flight path tilts more upward, the lift vector tilts away from the vertical. The vertical component of lift is the magnitude of lift times the cosine of the flight-path angle. So, even if lift itself increases somewhat with a higher angle of attack, the vertical projection shrinks because the lift is tilting forward relative to the vertical. In a steeper climb, more of the lift is directed fore-aft rather than straight up, reducing the portion that opposes gravity. Therefore, the vertical component of lift decreases when you increase the climb rate from 1000 fpm to 2000 fpm.