Definition
The speed at which a pilot increases the airplane's bank angle when entering a turn. A faster roll in rate means the wings tilt into the bank more quickly; a slower roll in rate means the bank is established more gradually.
Plain English
How quickly you tip the airplane into a turn. You can roll in fast or roll in slowly, and the choice depends on how steep the turn needs to be and how fast it needs to happen.
Context Anchor
Used in ground reference maneuvers such as turns around a point, where the pilot must enter and adjust the turn smoothly while holding a constant distance from a point on the ground.
Derivation
In aviation, “roll” means rotation of the airplane around its nose-to-tail line, which is what raises one wing and lowers the other. “Roll in” means to begin putting the airplane into that banked position for a turn.
Why Pilots Care
The correct roll in rate keeps the turn radius constant; too fast or too slow produces an elliptical ground track and fails the maneuver.
Grounding Statement
Picture starting a turn around a point on the ground: the roll in rate is how quickly you move from level wings to the bank needed for that turn.
Intuition Check
Do not read “roll” here as rolling along the ground. In this context, it means tilting the airplane’s wings to enter a turn.
Example Sentence 1
Because the airplane was on the downwind side of the point with a high groundspeed, the pilot used a quick roll in rate to establish a steeper bank before drifting outside the desired radius.
Example Sentence 2
On the downwind leg the student slowed the roll in rate so the turn would not tighten too quickly.