How are aircraft load factor limits established?

Load factor limits (n_limit) are established by: Structural design (FAR 25 requires n = 2.5 ultimate for transport at MTOW, with reduction allowed to n = 2.1 minimum for heavy aircraft), Occupant protection (human tolerance in crash and maneuver conditions), and System limits (hydraulic, electrical capability). Categories: Normal (FAR 23) +3.8 to -1.52g, Utility +4.4 to -1.76g, Aerobatic +6.0 to -3.0g. The V-n diagram shows how limits vary with speed. Load factor affects: Stall speed (increased by sqrt(n)), Structural fatigue (higher loads = shorter life), and Passenger comfort (typically <1.2g in turbulence for transports). Fighter aircraft are designed for +9/-3g with pilot g-suit protection.