Amazing how quickly the NTSB can investigate an accident which kills someone important. The average time for a regular fatality is 18 - 24 months for a factual.
FYI: the 18-24 month time frame is usually for a Probable Cause report. A Factual report, which has not been released for this accident, is usually released a week to 6 months after the Docket is opened to the public depending on the amount and complexity of the investigative results. Once a Factual is released you can then monitor the "completion" database below for possible Probable Cause report release date:
https://www.ntsb.gov/_layouts/ntsb.a...InvestRel.aspx