Technical Subject Areas
What the examiner is testing
This domain tests whether you can teach aerodynamics, systems, performance, weight and balance, weather, airspace, and regulations at a learner's level without losing accuracy. The examiner may ask you to explain a concept in two ways: once to a private pilot candidate and once to a commercial candidate. Strong answers connect the principle to a flight outcome.
Aerodynamics and performance
- Lift equation: L = 1/2 rho V squared S CL. Angle of attack, not airspeed alone, determines stall.
- Induced drag decreases as airspeed increases; parasite drag increases with the square of airspeed. Their crossover is L/D max, the basis for glide and endurance speeds.
- Load factor in a level turn: n = 1 / cosine(bank). At 60 degrees, n = 2.0. Stall speed increases by the square root of load factor, so a 50-knot stall speed becomes about 71 knots at 2 g.
- Stability: static versus dynamic; longitudinal, lateral, and directional. CG affects both stall speed and controllability.
- Density altitude raises true airspeed for a given indicated airspeed, lengthens takeoff rolls, and reduces climb performance.
Systems, weather, and regulations
- Teach systems by normal operation, indications, and failure modes: fuel, electrical, pitot-static, gyroscopic, hydraulic, and pressurization if installed.
- Weather products include METAR, TAF, PIREP, AIRMET, SIGMET, and G-AIRMET. Teach the difference between observed and forecast conditions.
- Airspace classes carry equipment, pilot certification, and weather-minimum requirements; 14 CFR Part 91 supplies the operating rules.
Worked example
A learner asks why a 60-degree steep turn feels heavy and why the airplane stalls sooner. Compute load factor: n = 1 / cos(60) = 1 / 0.5 = 2.0. The stall speed multiplier is the square root of 2, or 1.41. If the clean stall speed is 55 knots in level flight, the accelerated stall speed at 60 degrees bank is about 55 x 1.41 = 77.6 knots. At 70 knots and 60 degrees bank, the wing is already below its accelerated stall speed. The teaching point is that the turn itself raises the stall speed; the pilot must add power and limit bank at low airspeed.
Traps that cost marks
- Saying stall speed is fixed, or ignoring load factor when teaching turns and turbulence.
- Confusing adverse yaw with torque or P-factor when explaining rudder use.
- Explaining density altitude only as a temperature effect, without the pressure-altitude component.
- Teaching systems as memorized diagrams without failure symptoms or pilot actions.
- Using a regulation number incorrectly; if unsure, state the rule and mark the citation for review.