Definition
Flight in which the load on the airplane and its occupants equals the normal force of gravity — that is, the lift produced by the wings is exactly equal to the weight of the aircraft. In this condition, every part of the airplane and everyone in it weighs the same as they would standing still on the ground.
Plain English
Flight where you feel your normal body weight — no extra heaviness pressing you into the seat and no lightness lifting you out of it. The wings are producing just enough lift to balance the airplane's weight.
Context Anchor
Seen in angle of attack, stall, and maneuvering discussions when comparing normal straight-and-level flight with turns, pull-ups, or other maneuvers that change the forces on the airplane.
Derivation
The 'G' stands for the acceleration of gravity. '1G' means one times normal gravity — the force you feel just sitting in a chair. Pilots use multiples of G (2G, 3G, etc.) to describe how much heavier things feel during maneuvers.
Why Pilots Care
Stall speed, climb performance, and many handbook numbers assume 1G flight; any increase in load factor raises the speed at which the wing stalls.
Analogy
It is like standing on a bathroom scale. At 1G, the scale shows your normal weight; if extra force pushes you down, the scale would show more.
Grounding Statement
Straight-and-level cruise on a calm day is 1G flight — you feel your normal weight in the seat, nothing more, nothing less.
Intuition Check
Do not read “1G” as a speed, altitude, or power setting. It describes the amount of gravity-like loading the airplane is experiencing.
Example Sentence 1
The published stall speed assumes 1G flight, so in a 60-degree bank the airplane will stall at a noticeably higher airspeed.
Example Sentence 2
The handbook notes that 1G flight lets the angle of attack determine lift without the complications introduced by turns or pull-ups.