What is required to recognize engine failure during takeoff?

Recognizing engine failure during takeoff is critically linked to the V1 speed. V1 is defined as the decision speed during takeoff; it is the maximum speed at which a pilot can reject the takeoff safely. Beyond this speed, the aircraft must continue the takeoff even in the event of an engine failure. Therefore, identifying engine failure must occur by or before reaching this speed to ensure the safety of the aircraft and passengers. This recognition is vital, as it gives pilots the essential information needed to make decisions on whether to abort the takeoff or continue flying safely.

Monitoring other speeds, while important for various aspects of flight, does not provide the same level of critical information regarding engine performance during the takeoff roll as V1 does. VR speed relates to rotation, VMCG is the minimum control speed on the ground, and VA is design maneuvering speed, each serving specific functions but lacking the direct relevance to immediate engine failure recognition during the critical phase of takeoff when compared to V1.