Definition
The control inputs and resulting aircraft motion used to enter a bank (roll-in) and to return the wings to level (roll-out). The terms describe both the pilot's coordinated use of aileron and rudder and the airplane's response as it rotates about its longitudinal axis into or out of a turn.
Plain English
Roll-in is starting a turn by banking the wings. Roll-out is straightening the wings to end the turn. Together they describe how a pilot smoothly enters and exits a turn.
Context Anchor
Seen in ground reference maneuvers such as eights along a road, where the pilot must start and stop each turn at precise points over the ground.
Derivation
From the verb 'to roll,' meaning to rotate about a long axis. The airplane rolls about its longitudinal axis (nose to tail) when banking. 'In' refers to entering the bank, 'out' to leaving it and returning to wings-level.
Why Pilots Care
Precise roll-in and roll-out maintain coordination, prevent slips or skids, and keep the airplane on the intended ground track during training maneuvers.
Intuition Check
Do not read roll here as the airplane rolling along the ground. In this context, roll means tilting the wings in flight to enter or leave a turn.
Example Sentence 1
She began a smooth roll-in to a 30-degree bank as the airplane reached the road, then held the bank steady through the turn.
Example Sentence 2
At the proper point, the pilot initiated a coordinated roll-out to return to wings level.