EASA PPL Flight Performance & Planning (P70) — Study Guide

Flight Performance & Planning is chart- and number-heavy: POH graphs, mass & balance envelopes, fuel arithmetic, density altitude. The P70 paper is 20 questions · 60 minutes · 75% (15/20). Memorising single answers fails — you must follow each manufacturer's chart paths reliably under time pressure.

Atmospheric effects

Density altitude

Performance ties to ρ: hot, high, humid ⇒ higher density altitude ⇒ longer ground roll, weaker climb, TAS higher for same IAS. Think “performance altitude” vs indicated.

Pressure altitude from elevation + QNH

Set subscale to 1013.25 and read pressure altitude, or approximate: ~27 ft per hPa difference from 1013 applied to field elevation.

Example: elev 500 ft, QNH 1003 (10 hPa low) PA ≈ 500 + 10×27 = 770 ft

Track sign carefully — exams reward correct direction more than mental maths perfection.

Take-off performance

Distance stretches with high PA/temperature, mass, tailwind, uphill runway, soft/wet surfaces, and poor technique. Headwind and rated flap shorten the roll. Follow POH sequence: enter at OAT/PA/mass/wind/slope corrections exactly as the chart mandates — order differs by manual.

Accelerate-stop appears conceptually: abort decision speed recognition + stop distance after failure.

Climb performance

Vy — best rate of climb (ft/min priority). Vx — best angle (obstacle clearance). High density altitude and weight rob excess power ⇒ shallower climbs — extract from charts, don't guess.

Cruise and endurance

Higher power ⇒ higher TAS and disproportionate fuel flow (drag ~V²). Maximum range sits near best L/D speed; maximum endurance slower — exams love distinguishing them.

Mass and balance

moment = mass × arm
CG = sum(moments) / sum(masses)

Plot mass vs CG in the envelope — legal weight can still be illegal CG. Fuel burn shifts CG depending on tank geometry; check zero-fuel and landing conditions, not only take-off.

Fuel planning

Trip fuel = time × flow; add alternate, contingency (policy/state rule), and regulatory final reserve (tie back to OPS minima). Integration questions stack fuel mass into loading calculations — avgas ~0.72 kg/L (rule-of-thumb; verify POH).

Landing performance

Distance scales ~V² — +10% speed ⇒ ~+21% distance. Tailwind and downhill hurt most; full flap and firm braking discipline help. POH distances assume demonstrated technique — regulations may apply factors for public transport; understand exam wording on margins vs book figures.

Where students lose marks

• Pressure-altitude sign errors (low QNH ⇒ PA above field).
• Vx vs Vy scenario confusion (trees off far end vs need altitude quickly).
• Checking only departure mass & balance — missing aft CG after forward tanks burn.
• Linear approximation of kinetic energy effects on landing roll.

How to prepare

Photocopy POH-style graphs and run timed repetitions: identical workflow every question — enter axis → trace intersections → apply notes/wind/slope corrections → sanity-check magnitude. Pair every chart answer with a narrative (“hot/high ⇒ longer roll”) so wrong decimals trigger instinctive rechecks.