In order to establish the allowable landing weight for a transport category aircraft, the following details must be considered:
- Airfield pressure altitude
- Headwind component
- Runway length
- Runway gradient or slope
- Runway surface condition
With these details, it is possible to establish the maximum allowable landing weight, which will be the lower of the weights as dictated by:
- Landing runway requirements
- Approach climb requirements
In practice, the approach climb limitations (ability to climb in approach configuration with one engine inoperative) are seldom encountered because the landing weights upon arrival at the destination airport are usually low. However, as in the second segment climb requirement for takeoff, this approach climb gradient must be met and landing weights must be restricted if necessary. The most likely conditions that would make the approach climb critical would be the landings at high weights and high pressure altitudes and temperatures, which might be encountered if a landing were required shortly after takeoff.
Landing field requirements can more frequently limit an aircraft’s allowable landing weight than the approach climb limitations. Again, however, unless the runway is particularly short, this is seldom problematical as the average landing weight at the destination rarely approaches the maximum design landing weight due to fuel burn off.