Definition
The runway length at which the distance required to accelerate to takeoff decision speed (V1) and then stop the aircraft equals the distance required to accelerate to V1, lose an engine, and continue the takeoff to a specified screen height. At this length, the accelerate-stop distance and the accelerate-go distance are the same.
Plain English
The runway length where, if an engine fails at the decision point, the pilot can either stop or keep going and use exactly the same amount of runway either way.
Context Anchor
Seen in takeoff performance planning for larger or higher-performance airplanes, especially when checking whether a runway is long enough for the planned takeoff.
Derivation
Called 'balanced' because two different distances — the stopping distance and the continued-takeoff distance — are made equal, or 'in balance,' on the same runway.
Why Pilots Care
It determines the minimum runway length needed for safe operations when an engine failure occurs near the decision speed.
Intuition Check
Balanced does not mean the airplane is physically balanced. Here, balanced means the runway distance needed to stop and the runway distance needed to continue are equal.
Example Sentence 1
The crew checked the performance charts and confirmed the runway exceeded the balanced field length for their takeoff weight.
Example Sentence 2
Before departure the crew checked the performance charts to confirm the runway met the balanced field length requirement.