Definition
The maximum angles of bank, both left and right, that an autopilot or flight envelope protection system will allow the aircraft to reach before it intervenes to prevent further roll. In unusual attitude recovery protection systems, bank limits define the threshold beyond which the system automatically commands a return toward level flight.
Plain English
The most the aircraft is allowed to tilt left or right before the autopilot or protection system steps in and rolls it back toward level.
Context Anchor
Seen in discussions of unusual attitude recovery protection, flight control protection, autopilot behavior, and training standards for controlling aircraft attitude.
Derivation
Bank originally referred to a raised or sloping edge, like the side of a river. In flying, an airplane is said to bank because its wings tilt into a sloped position. Limit comes from a word meaning boundary, which fits the aviation meaning: a boundary for how far that tilt should go.
Why Pilots Care
Staying within bank limits prevents the airplane from entering a steeper unusual attitude or developing excessive roll rates that can lead to loss of control.
Grounding Statement
Picture the wings tilting left or right; the bank limit is the point where that tilt has reached the allowed boundary.
Intuition Check
Do not read bank as money or as a turn by itself. Here, bank means the airplane’s wing tilt, and bank limits are the maximum allowed amounts of that tilt.
Example Sentence 1
When the pilot became spatially disoriented and rolled aggressively to the left, the autopilot reached its bank limits and began rolling the aircraft back toward wings level.
Example Sentence 2
Exceeding bank limits while recovering in the clouds can turn a simple correction into a spiral dive.