What must be done before you can help an aircraft that is declaring an emergency without being radar identified?

Before assisting an aircraft that is declaring an emergency and is not radar identified, it is crucial to radar identify them first. Radar identification is essential in air traffic control because it confirms the aircraft's identity and provides accurate information about its location and flight characteristics. This identification ensures that any guidance or assistance provided to the aircraft is precise and tailored to its specific situation.

Once the aircraft is radar identified, air traffic controllers can effectively manage traffic, provide appropriate instructions, and coordinate the necessary emergency response. Without this identification, controllers may have difficulty ensuring safety among other aircraft in the vicinity and may also lack the data needed to provide the right assistance.

Other choices lack the fundamental requirement of establishing a clearly identified situation before providing effective help. Establishing their flight path, contacting the nearest airport, or requesting a change in frequency does not provide sufficient information or safety assurances without first confirming the aircraft’s identity through radar.