Plain English Meaning

The airplane is banked over and diving toward the ground in a tightening turn, picking up speed fast and losing altitude fast. The wings are still flying, but the situation will get dangerous in a hurry if the pilot doesn't recover.

Full Definition

A steep, descending turn in which the airplane is banked, the nose is well below the horizon, airspeed is increasing rapidly, and altitude is being lost at a high rate. The wings are still producing lift (the airplane is not stalled), which distinguishes a spiral dive from a spin. If not corrected, airspeed and load factor can quickly exceed structural limits.

Context Anchor

Encountered in stall, spin, and unusual- training, especially when to tell a true spin from a steep, fast descending turn.