What is the relationship between rotation speed (VROT) and maximum brake energy speed (VBMAX) that ensures a safe takeoff?

The relationship between rotation speed (VROT) and maximum brake energy speed (VBMAX) is crucial for ensuring a safe takeoff. VROT represents the speed at which the pilot initiates the aircraft's rotation to achieve lift-off, while VBMAX is the maximum speed at which the aircraft can use its brakes without risking excessive energy that could lead to brake failure or other issues.

For a safe takeoff, VROT must be less than VBMAX. This ensures that should the need arise to abort the takeoff while still on the runway, the aircraft can apply brakes safely without exceeding the maximum brake energy limit. If VROT were equal to or greater than VBMAX, there would be a risk of brake overheating or failure during an attempted stop, which could compromise safety.

Maintaining VROT below VBMAX provides a safety buffer, allowing for deceleration without excessive thermal stress on the braking systems, and ensures that the aircraft remains within operational limits during the critical phase of takeoff.