Traffic alert and collision avoidance system equipment and use

This regulation covers two simple requirements for Traffic Alert and Collision Avoidance Systems (TCAS):

Installation approval: Any TCAS installed in a U.S.-registered civil aircraft must be FAA-approved. You can't just install any collision avoidance system—it must meet FAA standards.

Operational requirement: If your aircraft has an operable TCAS, you must turn it on and keep it operating during flight. You cannot choose to leave it off.

In practice, this means if you're flying an aircraft equipped with TCAS (typically larger aircraft and jets), you're required to use it. The regulation doesn't mandate that all aircraft carry TCAS—that requirement comes from other regulations based on aircraft size and operation type. This rule simply says that if TCAS is installed and working, it must be approved and you must use it. The system provides automated traffic alerts and resolution advisories to help avoid mid-air collisions.

*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.*