Airborne weather radar equipment requirements

This regulation requires Part 135 operators to have working airborne weather radar on large transport category aircraft carrying passengers. The radar must be operational before departing under IFR or night VFR when thunderstorms or other radar-detectable hazardous weather is reasonably expected along the route. If the radar fails during flight, you must follow the procedures in your operations manual.

The rule includes several exceptions:

• Flights solely within Hawaii or Alaska
• Flights in a specific region of western/northern Canada
• Training, test, or ferry flights

These exceptions recognize areas where weather patterns differ or passenger safety isn't at stake. The regulation also clarifies that weather radar doesn't need a backup electrical power supply, unlike some other required equipment. This requirement helps ensure passenger-carrying flights can detect and avoid dangerous weather conditions that might not be visible to pilots, particularly at night or in instrument conditions.

*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.*