Identify the flight condition
Four forces. Two balanced pairs.
Select a force to see what it does.
Opposing pairs are balanced in this example. Arrow lengths are not to scale.
Lift balances weight
In this straight-and-level example, lift acts upward. Its magnitude equals weight, so the airplane does not accelerate vertically.
Straight, level, unaccelerated flight with horizontal thrust. Arrows share a diagram origin; their physical application points differ.
Illustration by The Pilot Method. Force relationships based on FAA PHAK, Chapter 5, Figure 5-1 ↗.
Start with one clear flight condition: straight, level, unaccelerated flight with thrust acting horizontally. In this example, lift balances weight and thrust balances drag. These pairs explain why the airplane’s velocity is not changing.
Balanced forces do not mean that the airplane has stopped. Ask your student to explain the difference between moving at a steady speed and speeding up. Their answer tells you whether they understand balance, rather than simply remember the names of four arrows.
Show where each arrow points before discussing a different flight condition. The arrows share an origin to make the drawing easier to read; their lengths and starting point do not show actual force magnitudes or attachment points. A climb, descent or turn needs its own force analysis.
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CFI Course with Written Prep and the study guide.