Final answer:
In aviation, a course reversal may not be executed when the procedure specifies 'No PT'. It is not necessary when flying a precision approach or when cleared by ATC. Course reversals can be performed in both VFR and IFR conditions depending on the situation.
Step-by-step explanation:
The correct answer is c) When the procedure specifies 'No PT'. In aviation, a course reversal refers to a maneuver that allows an aircraft to reverse its direction in order to align with the runway or approach path. However, there are certain situations when a course reversal is not necessary or prohibited. One of those situations is when the procedure clearly specifies 'No PT', meaning that a course reversal is not required according to the specific approach procedure.
For example, in instrument flight rules (IFR) operations, a precision approach is a type of approach where the aircraft follows a specific glideslope and localizer to land precisely on the runway. In such cases, a course reversal is not typically required because the aircraft is on a precise path towards the runway, guided by navigation aids and approach systems.
Therefore, when flying a precision approach ('a'), when cleared by air traffic control (ATC) ('b'), or when the procedure specifies 'No PT' ('c'), a course reversal is not executed. The option 'd' - 'Only during VFR conditions' - is incorrect because course reversals can be executed both in visual flight rules (VFR) and IFR conditions, depending on the specific situation and approach procedure requirements.