# Performance Class A (CS-25): Approach and Landing Theory

> Landing performance calculations, dispatch requirements, and factors.

- **Subject:** 032 — Performance
- **Section:** 032-04 — CS-25-Applicable Operational Requirements Performance Class A – Theory
- **Topic code:** 032-04-06
- **Last reviewed:** 2026-04-01
- **Author:** Pablo Asensio Martínez
- **HTML version:** https://pilotsyllabus.com/en/performance/cs-25-applicable-operational-requirements-performance-class-a-theory/approach-and-landing/

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## Climb Requirements

### Approach Climb (OEI)
During an approach (one engine inoperative), if a Go-Around is initiated:
*   **Configuration**: Approach Flaps, Gear Up, OEI, Take-off Thrust.
*   **Gradient Requirement**:
    *   **Two Engines**: 2.1%.
    *   **Three Engines**: 2.3%.
    *   **Four Engines**: 2.4%.

### Landing Climb (AEO)
Also known as "Balked Landing" (Go-Around from very low altitude/touchdown).
*   **Configuration**: Landing Flaps, Gear Down, AEO, Take-off Thrust.
*   **Gradient Requirement**: 3.2% (for all aircraft types).
*   This ensures the aircraft can climb away safely even in full landing configuration.

## Landing Distance Required (LDR)

The horizontal distance from a screen height of **50 ft** to a complete stop.

### Operational Factors (Dispatch)
At the planning stage (Dispatch), the aircraft must be able to land within a fraction of the available runway density (LDA).

*   **Dry Runway**: LDR $\le 60\%$ of LDA (or LDA $\ge 1.67 \times$ LDR).
*   **Wet Runway**: LDR $\le 60\%$ of LDA, then multiply the required distance by 1.15.
    *   Result: LDA $\ge 1.92 \times$ LDR Dry.

### In-Flight Calculation
Once in flight, for the actual landing, the "In-Flight" or "Advisory" landing distance is used (often called ALD or OLD). This removes the large 1.67 safety factor but adds a smaller operational margin (e.g., +15%).

## Factors Affecting LDR
*   **Mass**: Higher mass $\rightarrow$ higher $V_{REF}$ $\rightarrow$ longer distance. ($Distance \propto Mass^2$).
*   **Altitude**: Higher density altitude $\rightarrow$ higher TAS for same IAS $\rightarrow$ longer distance.
*   **Wind**: Tailwind increases distance significantly.
*   **Slope**: Downslope increases distance.
*   **Surface**: Water/Ice/Snow reduces braking action, increasing distance.

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Free study notes from pilotsyllabus.com. Not a substitute for training at an approved ATO.