Low-altitude windshear system equipment requirements

This regulation requires Part 121 air carriers to equip turbine-powered airplanes (turbojets, turbofans, etc.—but not turboprops) with windshear detection systems to help pilots avoid dangerous low-altitude windshear encounters during takeoff and landing.

For airplanes manufactured after January 2, 1991, operators must install either a windshear warning/flight guidance system, a detection/avoidance system, or a combination of both.

For older airplanes (manufactured before January 3, 1991), requirements vary by aircraft type. Specific models like the A-320, B-737-300/400/500, B-757, and B-767 need the more capable warning/guidance or detection/avoidance systems. All other turbine-powered airplanes need at minimum a windshear warning system, though they may install more advanced equipment.

The regulation allowed certificate holders to request extensions by submitting retrofit schedules, with compliance ultimately tied to TCAS II installation deadlines. This ensures airline jets have technology to detect and respond to windshear, a significant aviation hazard.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*