RA and TA No-Bearing Traffic

The no-bearing RA and TA messages show on the ND when

TCAS loses the bearing of the RA or TA traffic. The bottom

directional antenna becomes an omnidirectional antenna when

the landing gear is down. When this happens, the bottom

antenna cannot find the bearing of the intruder traffic. The

bearing is NCD. Because of this, the no-bearing messages show on the ND.

If a TA becomes no-bearing traffic, an amber TA with the range, altitude, and vertical motion arrow shows on the ND. If an RA becomes no-bearing traffic, a red RA with the range, altitude, and vertical motion arrow shows on the ND. Only two nobearing traffics may show.