Here is the ATC (Air Traffic Controller) recording that someone put on youtube. It is 8.5 minutes long. I went and did my own noise reduction on it. I think I can hear the words more clearly on my version. Its hard to make sense of what they’re saying so I urge you to use the transcript that I’ve uploaded. Then you’ll see that there are some pieces missing. But this will give you an idea of the most important parts of the conversation before the plane either broke up or crashed. The electronics also seems to be malfunctioning – perhaps due to the fire.
Here is a PDF file with the transcript. You will find it much easier to listen to if you read the transcript here: Helderberg_Transcript_CVR_MRU