1 — What Takeoff Distance Actually Measures
The POH gives you two numbers. Know exactly what each measures before using the charts.
2 — Reading the POH Chart
Every aircraft has its own charts giving a base distance for standard conditions at a pressure altitude and temperature. You then correct for non-standard conditions on top.
| Pressure altitude | Temperature | ||
|---|---|---|---|
| ISA −10 | ISA | ISA +10 | |
| Sea level | 430 m | 480 m | 545 m |
| 2,000 ft | 470 m | 520 m | 600 m |
| 4,000 ft | 530 m | 590 m | 680 m |
| 6,000 ft | 600 m | 680 m | 780 m |
| 8,000 ft | 690 m | 790 m | 915 m |
Illustrative SEP at MTOW, paved, calm, level. Real questions use your aircraft’s POH.
If your pressure altitude or temperature falls between values, interpolate proportionally. E.g. at PA 3 000 ft, ISA: halfway between 520 m and 590 m = 555 m.
3 — Correction Factors
The chart gives the base distance; real conditions are rarely standard. Apply each factor in sequence by multiplying the running total.
4 — Build Your Scenario
Pick conditions and watch each correction stack on top of the base distance.
5 — Worked Example (Exam-Style)
Given elevation 1 500 ft · QNH 1 001 hPa · OAT 28 °C · 10 kt headwind · dry paved · level:
- Pressure altitude: PA = 1500 + (1013 − 1001) × 30 = 1 860 ft → use the 2 000 ft row.
- ISA deviation: ISA at 2 000 ft = 11 °C; OAT 28 °C → ISA +17 → base ≈ 600 m (ISA +10 column).
- Wind: 10 kt headwind → −10% → 600 × 0.90 = 540 m.
- Surface & slope: dry paved, level → no correction.