Definition
The painted or imaginary line running lengthwise down the exact middle of a runway or taxiway, used as the primary directional reference for takeoff, landing, and ground operations.
Plain English
The line down the middle of the runway. Pilots aim to keep the airplane tracking along it during takeoff and landing.
Context Anchor
Seen during taxi, takeoff roll, landing, and any instruction to keep the airplane aligned with the runway.
Why Pilots Care
Keeping the aircraft on the centerline prevents runway excursions that could lead to loss of control, propeller strikes, or runway-edge damage.
Intuition Check
Do not think of centerline as just any line near the middle. In this context, it means the runway’s middle path that the pilot uses for alignment.
Example Sentence 1
As the airplane accelerated down the runway, the pilot used rudder pressure to keep the nose tracking straight along the centerline.
Example Sentence 2
After touchdown a crosswind pushed the airplane slightly left of the centerline before the pilot corrected back to center.