Which component is crucial in detecting the aircraft's position without using external signals?

The correct component for detecting an aircraft's position without relying on external signals is gyros. Gyros, or gyroscopes, are essential instruments in aircraft that utilize the principles of angular momentum to maintain orientation. They can accurately measure the aircraft’s rate of rotation along its axes, which is critical for navigation and stability.

Unlike systems such as GPS, which depend heavily on satellite signals for determining location, gyros function independently and provide continuous data on the aircraft’s orientation and attitude relative to the Earth. This internal reference is vital, especially when external signals might be compromised or unavailable, such as in certain military operations or regions where satellite signals are unreliable.

Devices like ADF (Automatic Direction Finder) and wireless transmitters also depend on external signals, such as radio waves, and are therefore not suitable for self-contained position detection. In summary, gyros are irreplaceable for internal measurement of an aircraft's position and orientation, making them essential for flight control and navigation without reliance on external references.