Aircraft Airworthiness and Performance
The Aircraft Airworthiness and Performance domain checks two things: whether the airplane is legally and mechanically fit to fly, and whether it can actually do what you are asking of it on today's runway, at today's temperature, at today's weight.
Airworthiness and inspections
- An annual inspection must have been completed within the preceding 12 calendar months. The 100-hour inspection applies to aircraft used for hire or for flight instruction, so it usually does not apply to your own recreational flying.
- Every Airworthiness Directive that applies to the airframe, engine, propeller, or appliances must be complied with and documented.
- The ELT needs a 12-month inspection; its battery is replaced at 50 percent of shelf life or after one hour of cumulative use.
- Transponder and static-system checks (24 months) matter only when that equipment is required for the flight; VFR does not require a VOR check.
- Preventive maintenance you may perform yourself is listed in Part 43, Appendix A.
Required equipment under 91.205
Day VFR: TOMATOFLAMES - tachometer, oil pressure gauge, manifold pressure gauge (constant-speed propeller), altimeter, temperature gauge, oil temperature gauge, fuel gauge, landing gear position indicator, anti-collision lights, magnetic compass, ELT, safety belts, plus the airspeed indicator. At night add the FLAPS items: fuses, landing light, anti-collision lights, position lights, and a source of electrical power.
Preflight action and performance
91.103 requires weight and balance, runway lengths, takeoff and landing distances, fuel, alternates, weather, and known ATC delays before flight. Density altitude equals pressure altitude plus 120 times (OAT minus ISA temperature), where ISA temperature is 15 °C minus 2 °C per 1,000 feet.
Worked example
Field elevation 4,000 ft, altimeter 29.92, OAT 30 °C. Pressure altitude is 4,000 ft and ISA temperature is 15 − 8 = 7 °C, a spread of 23 °C, so density altitude is 4,000 + 120 × 23 = 6,760 ft. Enter the performance chart at 6,760 ft, not 4,000 ft: expect roughly 3 percent more ground roll per 1,000 ft of density altitude, or on the order of 8 percent, plus a weaker climb.
Traps
Using field elevation when the altimeter setting is not 29.92. Reading the over-50-foot-obstacle distance for an unobstructed runway. Forgetting that a headwind shortens ground roll but does not change indicated airspeed or stall speed. Treating weight and balance as a one-time calculation instead of one per loading.