Performance - landing
Performance - landing tests whether you can establish a legal landing mass and distance for the destination or alternate. It covers landing distance available, approach speed, screen height, braking configuration, runway condition and go-around performance.
Rules and factors
- The landing distance required is the actual distance from 50 ft multiplied by the approved factor; wet and contaminated increments are additional and AFM-specific.
- LDA must be sufficient after allowing for displaced thresholds and any runway works.
- Vref and approach speed additives must follow the AFM; excessive speed increases distance.
- Reverse thrust credit is allowed only where the AFM and operator policy permit it; autobrake settings change stopping distance.
Worked example
Actual landing distance from 50 ft is 1,000 m. Using the illustrative dry factor 1.67 gives 1,670 m. A wet increment of 15% gives 1,920 m. With LDA 2,000 m the wet landing is legal with 80 m margin. If a displaced threshold reduces LDA to 1,900 m, the same wet landing is not legal; you need lower mass, a different runway or another alternate.
Traps
Do not treat the actual landing distance as the required distance. Do not apply a wind additive to the chart in the wrong direction. Reverse thrust is not automatically usable credit. Check the missed-approach climb requirement as well as the stopping case, especially at high altitude or high mass.