Definition
Areas around an aircraft that a pilot cannot see from the cockpit due to obstructions such as the airframe, wings, fuselage, engine cowling, window posts, or other structural components. These regions hide other aircraft, terrain, or obstacles from view during normal scanning.
Plain English
Parts of the sky and ground around your airplane that you simply cannot see from where you sit, because the airplane itself is in the way.
Context Anchor
Pilots deal with blind spots during visual scanning, taxiing, turns, traffic avoidance, and before changing direction on the ground or in the air.
Derivation
The phrase comes from “blind,” meaning unable to see, and “spot,” meaning a place. It is also used for the natural small area in the human eye that does not detect an image, but in aviation it usually means an area hidden from the pilot’s view by the airplane or the pilot’s position.
Why Pilots Care
Unseen traffic in blind spots is a leading factor in mid-air collisions; systematic scanning and clearing turns are required to compensate.
Analogy
Like the blind spot in a car when changing lanes -- you have to physically move or turn your head to see what the structure is hiding.
Intuition Check
Do not assume a blind spot means there is nothing there. It means you cannot see that area from your current position.
Example Sentence 1
Before turning base, the pilot lifted the wing briefly to clear the blind spot beneath the high-wing trainer.
Example Sentence 2
Before taxiing onto the runway, she leaned forward and checked both sides for traffic hidden in the aircraft's blind spots.