14 CFR · Part 121
14 CFR § 121.356
Collision avoidance system.
Effective January 1, 2005, any airplane you operate under this part must be equipped and operated according to the following table:
Collision Avoidance Systems
| If you operate any— | Then you must operate that airplane with— |
|---|---|
| (a) Turbine-powered airplane of more than 33,000 pounds maximum certificated takeoff weight | (1) An appropriate class of Mode S transponder that meets Technical Standard Order (TSO) C-112, or a later version, and one of the following approved units: (i) TCAS II that meets TSO C-119b (version 7.0), or takeoff weight a later version. |
| (ii) TCAS II that meets TSO C-119a (version 6.04A Enhanced) that was installed in that airplane before May 1, 2003. If that TCAS II version 6.04A Enhanced no longer can be repaired to TSO C-119a standards, it must be replaced with a TCAS II that meets TSO C-119b (version 7.0), or a later version. (iii) A collision avoidance system equivalent to TSO C-119b (version 7.0), or a later version, capable of coordinating with units that meet TSO C-119a (version 6.04A Enhanced), or a later version. | |
| (b) Passenger or combination cargo/passenger (combi) airplane that has a passenger seat configuration of 10-30 seats | (1) TCAS I that meets TSO C-118, or a later version, or (2) A collision avoidance system equivalent to has a TSO C-118, or a later version, or (3) A collision avoidance system and Mode S transponder that meet paragraph (a)(1) of this section. |
| (c) Piston-powered airplane of more than 33,000 pounds maximum certificated takeoff weight | (1) TCAS I that meets TSO C-118, or a later version, or (2) A collision avoidance system equivalent to maximum TSO C-118, or a later version, or (3) A collision avoidance system and Mode S transponder that meet paragraph (a)(1) of this section. |
Reflects the eCFR edition current as of September 29, 2026. Retrieved from ecfr.gov on October 16, 2026.
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