What is the daytime signal indicating there are no brakes on the aircraft?

The correct answer is that the tailhook down position serves as the daytime signal indicating that there are no brakes on the aircraft. This signal is crucial for ground crews and other personnel who need to be aware of the status of the aircraft during operations. When the tailhook is deployed, it communicates clearly that the aircraft is not brake-secured, which is essential for safety on the flight line and during potential movements.

In aviation operations, other signals such as wings positioned down are used for signaling different statuses, like readiness for takeoff or indicating that the aircraft is secure for maintenance. Deployed chocks are utilized as a physical barrier to prevent movement and indicate that the aircraft is secure, but they do not specifically signal the lack of brakes. The engine warning light being on indicates a malfunction related to engine performance and does not inform ground personnel about the braking status of the aircraft. Each of these signals serves a distinct purpose, but only the tailhook down specifically indicates that the aircraft is not equipped with functional brakes.