The recovery tanker shall be level at what altitude prior to turn to final bearing?

Answer: C — 600 feet

The correct altitude for the recovery tanker to be level prior to turning to the final bearing is 600 feet. This altitude is crucial because it helps ensure safe and effective positioning during the recovery phase of an operation. Positioning the tanker at this specific altitude allows for an adequate buffer above the minimal safe altitude while also facilitating a stable environment for approaching aircraft. Maintaining a level flight at 600 feet helps in managing airspeed and ensures that any subsequent maneuvers, such as turning to a final bearing, can be executed smoothly and safely. Adhering to this altitude also aligns with standard operational procedures, which are designed to minimize the risk of collision with terrain or other aircraft during critical phases of flight. Thus, taking into consideration both safety and operational efficacy, 600 feet is deemed the appropriate altitude for the recovery tanker before executing the final turn.