What does "V1" refer to in the context of takeoff performance?

"V1" is a critical speed during the takeoff phase of flight, which designates the point during the takeoff roll at which the pilot must make a decision. Beyond this speed, the aircraft has reached a point where it is no longer safe to abort the takeoff. If an engine failure or another significant issue occurs after V1, the pilot is committed to continuing the takeoff to ensure safety, as the aircraft may not have sufficient runway remaining to stop safely. This speed takes into account considerations such as aircraft weight, runway length, and weather conditions, ensuring that pilots have a clear operational guideline regarding when it is safe to stop or continue during the takeoff sequence. Understanding V1 helps pilots make informed and timely decisions, contributing to flight safety during critical phases of operation.