I was considering writing an article for the wreckchasing board on just this very subject (may be a good topic for the next convention....)! I can easily talk about this for a while, so I'll try to stick to a Cliff's Notes version:
Ms. Wharton is correct. The AIB reports are retained at the Major Command (MAJCOM) (e.g., Air Combat Command, Air Force Global Strike Command) for a period of three years before going the National Records Center. Unless there is a compelling interest (i.e., historically significant mishap), the reports are destroyed 25 years from the date of the mishap. With few exceptions, only those reports published for 1986 and later would still be available. To its credit, the AF has been making the executive summaries of AIB reports available on the web at: http://usaf.aib.law.af.mil/
Additionally, some of the MAJCOMs have been making the full AIB report (and supporting material) available on their own public websites. ACC, for instance, has the B-2 crash on Guam featured on its page at http://www.acc.af.mil/media/index.asp
to include video and animation of the mishap sequence.
So what's the difference between the reports?
When you order a report from the AF Safety Center at Kirtland AFB, NM (1956 and later reports), you are receiving the report of the Safety Investigation Board (SIB). The SIB is governed by Air Force Instruction (AFI) 91-204 and is convened to investigate mishaps involving AF personnel and property. The primary focus is on accident prevention...the goal is to determine what happened, and how to prevent the mishap from happening again. What makes the post-1956 reports special is that they are in two parts. The part you receive (Part 1, tabs A to S) is factual in nature, and may contain witness statements not given under privilege, teardown reports, drawings, and photographs. Part 1 is releasable to the public, and is also provided to the AIB (if convened). Part 2 (Tabs T to W) contain privileged witness statements, For Official Use Only (FOUO) information, and the conclusions and recommendations of the SIB. Tab 2 is not releasable to the public, nor do I believe it ever will be. The stance of the AF is that the privileged witness statements are given under a blanket of confidentiality, and this promise does not expire. If witnesses gave testimony under privilege, and this testimony later (even much later) becomes public, it would compromise the ability to gather safety information. A Supreme Court decision from 1986 ruled that safety privilege trumps FOIA.
What you see when you read a newspaper article regarding a crash is information from the Accident Investigation Board (AIB). The AIB is governed by AFI 51-503, and is usually convened by the same person (MAJCOM Commander or his designee) who convened the SIB. The AIB is an investigation from a legal standpoint...the goal is to determine what happened, prepare a report that is fully releasable, brief next-of-kin of members killed in the mishap (or those who survived and were seriously injured), and determine if a liability exists or if adverse action needs to be taken. Since the report is intended for public consumption, a FOIA request isn't necessary, though it may be an easy vehicle to do so. Otherwise a letter to the MAJCOMs Staff Judge Advocate (SJA) should suffice.
While a SIB might be convened for several classes of mishaps, the AIB is usually convened only when a Class A mishap occurs (property damage of $2 Million or more, fatality or total permanent disability, or loss of an aircraft). AIBs are optional for other mishap classes, and may not be convened in all Class As (for instance, if only government property is damaged).
Yep, Cliff took a bunch of notes....