PPL theory · learn with explanations
When studying PPL principles of flight, connect each answer to aircraft behaviour. These examples review angle of attack, load factor and induced drag. The explanations also clarify the conditions in each question: a formula applies only when its assumptions hold.
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For PPL principles of flight questions, connect definitions to precise conditions. A stall occurs when the critical angle of attack is exceeded. For turning questions, check whether the turn is coordinated and altitude is maintained: those are the conditions in the load factor example. When comparing induced drag, check which other quantities remain constant; its relationship with lift applies under the conditions stated in the question. Reading the assumptions is part of solving the problem, before selecting an answer.
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Exceeding the critical angle of attack.
A stall is associated with exceeding the critical angle of attack and flow separation over the wing. Indicated stall speed varies with weight, configuration and load factor, so a stall can occur at different speeds and attitudes. Airspeed alone does not define the aerodynamic condition.
2 g.
For a coordinated level turn, n = 1 ÷ cos(bank angle). Since cos(60°) = 0.5, the load factor is 2. The wing must produce lift equal to twice the weight to maintain the required vertical component. The formula does not apply in the same way to a descending or uncoordinated turn.
It becomes four times as large.
Under the stated conditions, induced drag is proportional to the square of lift. Doubling lift therefore multiplies induced drag by 2² = 4. This is the component associated with producing lift, distinct from parasite drag.
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Practise for freeStudy exercises, not official examination questions. To explore the concepts: FAA · Pilot’s Handbook of Aeronautical Knowledge.
