What must a pilot do if visual references are lost during takeoff?

When visual references are lost during takeoff, the most appropriate action a pilot should take is to abort the takeoff. This decision is crucial because losing visual references can significantly impair the pilot's ability to maintain control of the aircraft. In such situations, the aircraft may not be able to safely climb or navigate as intended, which can pose a serious risk to both the crew and passengers. Aborting the takeoff allows the pilot to bring the aircraft to a stop on the runway, thereby avoiding any potential accidents that could arise from continuing without adequate situational awareness.

Taking off without visual references can lead to a loss of control, making it difficult for the pilot to effectively respond to the aircraft's behavior. This is particularly critical during the takeoff phase, where external references are essential for maintaining the correct flight path and ensuring safety.

The other options may lead to hazardous scenarios. Continuing to rotate or gaining altitude immediately could result in a critical loss of control, leading to potential accidents. Contacting air traffic control may be necessary after ensuring safety, but the priority should be to safely stop the aircraft on the runway first. Understanding the importance of maintaining visual references during takeoff is vital for safe aviation practices.