Runway Required Calculator
Calculate runway requirements with regulatory safety factors.
Regulatory Factors
| Operation | Takeoff | Landing |
|---|---|---|
| Part 91 | 1.0x | 1.0x |
| Part 121 Dry | 1.15x | 1.67x (60%) |
| Part 121 Wet | 1.15x | 1.92x (52%) |
| Part 135 SE | 1.0x | 1.67x (60%) |
| Part 135 ME | 1.15x | 1.67x (60%) |
Understanding Runway Requirements
Takeoff Field Length
For transport category aircraft, takeoff field length is the greatest of: 1) 115% of takeoff distance with all engines, 2) Takeoff distance with engine failure at V1, 3) Accelerate-stop distance.
Landing Distance Factors
FAR 121 requires landing distance not exceed 60% of available runway (1.67x factor). For wet runways, this increases to 52% (1.92x factor). Part 135 uses similar requirements.
Contaminated Runways
Standing water, slush, snow, or ice significantly affect performance. Operators should use specific contaminated runway performance data from the AFM.
Balanced Field Length
The balanced field length is when accelerate-stop distance equals accelerate-go distance. This is the minimum runway required for safe operation considering engine failure at V1.