The NTSB does not investigate DOD mishaps; the DOD does. Every unit has a standing Aircraft Mishap Board nominated by the unit commander which includes the Saf

The NTSB does not investigate DOD mishaps; the DOD does. Every unit has a standing Aircraft Mishap Board nominated by the unit commander which includes the Safety Officer and other senior aviators. There are formal Aviation Safety Schools which you have to graduate from in order to hold the position of Safety Officer which train you on how to conduct an aircraft mishap investigation. Every time there is a mishap, two investigations run concurrently. The Aircraft Mishap Board conducts a safety investigation, and another officer conducts a legal investigation to ascertain criminal culpability. The safety investigation takes priority for resources, access to evidence, etc. The legal investigation is FOIA-able. The safety investigation is privileged and confidential under Federal law, cannot be released to the public, and individuals who testify for it are granted immunity. The goal is to ensure that everyone's cards are on the table and to have complete transparency in private, so that the proper corrective actions can occur. The investigation reports go up the chop chain to a general officer or flag officer who is authorized to approve them, and each commander along the way can offer their comments or propose alternative interpretations of the evidence. The approving commander then orders the proper changes in procedures or rules to be applied, or orders discipline or administrative sanctions if warranted. And yes, if classified information was deemed germane to an investigation because it related to one of the assessed causal factors, the investigation would be classified appropriately. Or perhaps there might be a classified annex attached to an otherwise unclassified report to simplify handling, with notes saying "see reference (a)." when appropriate. Or if Controlled Unclassified Information was involved, that information would be blocked from release if there was ever a FOIA.