One of the many functions of the National Transportation Safety Board (NTSB) when it investigates an adverse aviation event is the classification of the event as either an accident or an incident as defined by 49 CFR Part 830.

Recently, Mike Hodges, Air Safety Investigator, and Clint Crookshanks, Aerospace Engineer (Structures) both of the NTSB wrote an article on the NTSB blog, NTSB Safety Compass which discusses the process that they must go through to make the determination.

Of course, the process starts with the definition of each type of event but the investigation must often dig much deeper into the condition of the aircraft than is shown by an exterior visual inspection.