Story ID: 
FAA Cautions Pilots on Runway Length Sources
By: Amy Wilder
Caption: FAA urges use of its Chart Supplement data, attention to declared distances
Word Count: 367
In a recently issued Information for Operators (InFO), the FAA warned that “many operators or pilots are referencing or using the wrong runway length source data when performing takeoff and landing data calculations,” adding that this type of error could lead to inaccurate aircraft performance calculations and possible runway overrun.
Guidance in the InFO emphasizes that runway information varies depending on the source and that not all published runway lengths are suitable for regulatory performance calculations. While the FAA publishes runway length and width data in the Chart Supplement, the InFO notes that operators must pay particular attention to declared distances—takeoff distance available, takeoff run available, accelerate-stop distance available, and landing distance available—when determining whether a runway can be accepted.
“Declared distances are the distances that an airport declares available for use in meeting an airplane’s regulatory performance requirements,” the InFO states. Declared distances that are not separately listed are generally assumed to equal the runway’s physical length, except for landing distance available, which is reduced by any displaced threshold.
Related FAA guidance in the Aeronautical Information Manual explains that declared distances are intended to provide standardized values for performance planning and regulatory compliance, reinforcing the InFO’s emphasis on using official published data rather than inferred or aggregated runway dimensions.
The document cautions that some commercially produced flight publications display physical runway length, stopways, overruns, or other usable lengths that may be misinterpreted. “Airport diagrams or airport information pages are designed to facilitate ground movement of aircraft, not for obtaining accurate runway distance information for performance planning,” the InFO says.
Onboard databases and flight management system calculations may not be up to date and “might not reflect the actual runway available for takeoff and landing performance calculations,” particularly when declared distances are not included, the FAA added.
The InFO strongly recommends that pilots and operators “reference the appropriate FAA Chart Supplement for runway declared distance information for preflight planning or in-flight landing distance assessments,” noting that the data is drawn directly from FAA Form 5010 airport records. It further advises operators not to attempt to calculate declared distances independently.