Final answer:
The required climb gradient when departing runway 15 into IMC conditions depends on the specific airport departure procedure and the aircraft's performance. Typically, unless otherwise specified, a minimum gradient of 200 ft/nm is expected for obstacle clearance. The exact gradient must be determined from the relevant procedure and aircraft data.
Step-by-step explanation:
The question pertains to the required climb gradient for an aircraft when departing on runway 15 (which could be any runway designated as 15, typically meaning it is oriented approximately 150 degrees from magnetic north) into Instrument Meteorological Conditions (IMC). The climb gradient is the ratio of altitude gained to the distance traveled over the ground and is expressed in feet per nautical mile (ft/nm). The climb gradient required can vary widely depending on the particular airport's departure procedure, the presence of obstacles, and the performance capabilities of the airplane.
Since the question does not provide specific departure procedure information for runway 15 nor the performance data for the particular aircraft, it is impossible to provide a definitive answer from the provided options. Typically, departure procedures published in aeronautical information publications will specify the required climb gradient. If this information is not provided, regulations usually specify a minimum climb gradient of 200 ft/nm to ensure obstacle clearance, but this is only a typical minimum and not applicable to all cases. Pilots must refer to the specific departure procedure for the relevant runway and their aircraft's performance data to determine the exact required climb gradient when departing into IMC conditions.
Without specific procedural details, it is appropriate to default to the standard or expected minimum climb gradient, which is usually 200 ft/nm unless otherwise specified in the departure procedure or by the aircraft's performance charts.