What are the large wing feathers on a raptor commonly referred to as?

The large wing feathers on a raptor are correctly referred to as primaries. Primaries are critical for flight, providing the necessary lift and thrust as the bird flaps its wings. These feathers are located on the outerwing and play a crucial role in the bird's ability to maneuver and stabilize in the air.

Primaries differ from other types of feathers, such as secondaries, which are located closer to the bird's body and contribute to lift but not to thrust in the same way. Shafts refer to the central stem of a feather, not a specific type of feather itself. The term 'sails' is not a standard term used in ornithology to describe wing feathers in birds, including raptors. Therefore, the correct terminology—primaries—highlights their specific function and anatomical importance in avian flight.