Which of the following statements about restricted areas is true?

• A. They are always off-limits.
• B. They can be entered with weather clearance.
• C. They require flight plans.
• D. They may be penetrated with the controlling agency's authorization.

Answer: (D)

Restricted areas are sections of airspace where activities conducted there can be hazardous to nonparticipating aircraft, so access is controlled. They are not permanently off-limits; entry is possible if you obtain authorization from the controlling agency, typically the military or the agency in charge of that area. To penetrate, you’d request and receive a clearance from the controlling authority (often coordinated through ATC), and you must heed times of operation and altitude boundaries shown on charts. Weather clearance or filing a flight plan does not by itself allow entry—the required factor is the specific authorization to enter.