For a VFR Western departure from KNSE to Area 1, when should an aircraft turn to 270 degrees?

The correct action for a VFR Western departure from Naval Air Station Whiting Field (KNSE) is to turn to 270 degrees when instructed to "Proceed On Course." This instruction is vital as it indicates when the pilot can safely redirect their flight path in accordance with air traffic control (ATC) directives.

As part of standard departure procedures, ATC will provide specific instructions based on traffic, weather, and flight safety considerations. Turning on course upon receiving this instruction ensures that the aircraft is safely maneuvering while complying with ATC instructions, which help maintain orderly and safe air traffic.

In the context of the other options, turning at 4200' MSL or climbing to 6500' MSL does not encapsulate the procedural aspect that emphasizes following ATC guidance. Similarly, being overhead Point Nugget does not inherently dictate a specific course change without a relevant instruction from ATC. Therefore, the focus should always be on adhering to directives given by ATC to ensure flight safety and proper airspace management.