AFM performance charts — overview
A PPL student must be able to read and interpolate the following charts in the AFM/POH of their aircraft for a specific planned flight:
| Chart | Inputs | Output |
|---|---|---|
| Take-off ground roll and 50-ft distance | Pressure altitude, OAT, mass, wind, slope, surface | TODR ground roll and TODR to 50 ft |
| Climb performance | Pressure altitude, OAT, mass | RoC at Vy or climb gradient at Vx |
| Cruise table | PA, OAT, power setting (% power / MAP+RPM) | TAS, fuel flow, endurance |
| Range / endurance | Fuel quantity, power setting | nm or hours |
| Landing distance | PA, OAT, mass, wind, surface | LDR ground roll and LDR from 50 ft |
| Stall speed | Configuration, bank angle | Vs0, Vs1, Vs |
| Cross-wind component | Wind (direction/strength), runway QFU | Crosswind and headwind component |
Chart-use tips
- Pressure altitude (PA) first: PA = (1013 hPa − QNH) × 27 ft/hPa + indicated altitude — or briefly set altimeter to 1013 and read.
- OAT from ATIS or weather report.
- Linear interpolation between table values — no extrapolation outside the table range!
- AFM correction factors: wet runway, grass, slope, wind (often the 50 %/150 % rule).
- Safety factor: e.g. × 1.33 on TODR/LDR (EASA recommendation for non-certified surfaces or performance verification).
Skill-test requirement
In the skill test the examiner specifically expects:
- Performance calculation for the planned flight before take-off.
- Explanation of each step and reasoning.
- Identification of safety margin.