At what altitude and DME does an aircraft start its turn to final during a CV-2 approach?

The correct choice is based on the standard procedures for a CV-2 (Carrier Variable-2) approach, which typically involves specific altitudes and distances measured in nautical miles (DME) for timing the turn to final approach.

When performing a CV-2 approach, the aircraft is designed to begin its turn to final when it reaches one-third of the marshal altitude along with a DME distance of 10 nautical miles. This procedure helps ensure that the aircraft is at the correct configuration and altitude prior to the final approach to the carrier, allowing for a safe and efficient landing.

Starting the turn at one-third of the marshal altitude means that if the marshal altitude is, for example, 900 feet, then the turn would commence at approximately 300 feet. This height is vital for maintaining a controlled descent and aligning properly with the flight path required for landing on a carrier, while also allowing for adequate time to configure the aircraft as necessary before final approach.

In context, other choices do not align with the established procedures for the CV-2 approach or may not use appropriate configuration altitudes, making this particular answer the correct one for ensuring a safe and effective approach.