US Patent 11069939 Underwater locator device (ULD) particle suppressor/trap

An avionics unit assembly for an aircraft includes an avionics unit such as an underwater locator device (ULD) having a transmitter configured to output a radio frequency pulse and a battery configured to power the device. The avionics unit assembly can further include a housing that encases the transmitter and the battery and includes a vent port for exhausting an emission from the housing during a failure of the avionics unit. The avionics unit assembly can further include one or more of a suppressor that filters the emission, a shield element that is resistant to chemical and/or thermal effects of the emission, and a bracket for mounting the avionics unit assembly to a surface. The suppressor can include a plurality of channels, where each channel includes at least one blind alley that can capture/filter a particulate component and/or a liquid component from the emission and/or break up the particulate component.