The National Transportation Safety Board has started its investigation into the aviation incident that killed Greg Biffle, his family and three others on Thursday morning at Statesville Regional Airport.<br>While a preliminary report will be released within 30 days, a full investigation will take 12 to 18 months before the publishing of a final report.<br>NTSB Member Michael Graham conducted a ...<a class='more' href='https://www.motorsport.com/nascar-cup/news/investigation-timeline-into-fatal-greg-biffle-plane-crash-released/10785825/?utm_source=RSS&utm_medium=referral&utm_campaign=RSS-ALL&utm_term=News&utm_content=www'>Keep reading</a>