  AERA, the Auger Engineering Radio Array, located at the Pierre Auger
Observatory in Malarg\"ue, Argentina measures the radio emission of extensive
air showers in the 30-80 MHz frequency range and is optimized for the detection
of air showers up to 60$^{\circ}$ zenith angle. In this contribution the
motivation, the status, and first results of the analysis of horizontal air
showers with AERA will be presented.
