Hindustan Aeronautics Limited (HAL) said it has received the Indian Technical Standard Order (ITSO) authorisation from DGCA for its indigenously developed Cockpit Voice Recorder (CVR) and Flight Data Recorder (FDR). CVR and FDR are commonly known as 'black boxes'. ITSO is a minimum performance standard for specified materials, parts, processes and appliances used on civil aircraft, HAL said.