Performance, Weight and Balance, and Takeoff/Landing Limitations
Performance Fundamentals
Agricultural aircraft operate near maximum gross weight at takeoff and return light after application. Candidates must understand how density altitude, temperature, humidity, and field elevation affect takeoff distance and climb performance. High density altitude reduces power output and lift, increasing takeoff roll and reducing climb gradient, which is dangerous at low level. Weight and balance is critical because the hopper load is a large fraction of gross weight and its position affects center of gravity.
Weight and Balance Traps
Know that the hopper is located near the center of gravity, so load changes affect total weight more than CG position, but chemical tank placement and any equipment changes still require verification against the envelope. A common trap is treating the maximum hopper capacity as always usable; performance limits may require reduced loads at high density altitude or short fields.
Worked Example
Rule of thumb: for every 1,000 feet of density altitude increase, expect a noticeable increase in takeoff distance and reduced climb rate. If a question presents a hot, high, humid field, the correct answer usually involves reducing load or rejecting the takeoff rather than accepting marginal performance.
Takeoff and Landing Limitations
Watch for questions about obstacle clearance after takeoff, the need for a defined emergency turn-back or forced landing plan, and landing distance on soft or short strips. Also remember that tailwind and runway slope compound performance penalties.