How should performance data in the Aircraft Flight Manual (AFM)/Pilot Operating Handbook (POH) be treated?

Performance data in the Aircraft Flight Manual (AFM) or Pilot Operating Handbook (POH) should be adjusted for non-standard atmospheric conditions because the performance of an aircraft can vary significantly based on various environmental factors. These factors include temperature, pressure, and humidity, all of which can affect an aircraft's ability to take off, climb, and land safely.

When the data is generated, it is typically based on standard atmospheric conditions defined at sea level (ISA - International Standard Atmosphere). However, it is essential for pilots to understand how to interpret this data under different conditions. For instance, higher temperatures can lead to reduced engine performance, increased takeoff distances, and a decrease in climb rates. Therefore, to ensure accurate performance assessments and safe operation, pilots must adjust the performance data according to the actual environmental conditions encountered during flight.

By recognizing the need for these adjustments, pilots can make better-informed decisions about their flight, ensuring that they adhere to safety margins and comply with operational requirements while maximizing efficiency and performance.