Dear Mr. Morris,
Thank you for posting your request on History Hub!
Air Force accident reports dated after 1955 are in the custody of the Air Force Safety Center, 9700 G Avenue SE, Kirtland Air Force Base, NM 87117-5670. The website is https://www.safety.af.mil/Contact-Us. When you submit your request using the contact form, please select FOIA Office (Mishap Reports) as the recipient. Be sure to specify in your request that this is for a disability claim.
We hope this is helpful.
Newspapers.com has multiple articles about 1966-1968 Davis Monthan crashes that may assist you. There are articles from newspapers around the nation.
For search terms I entered:
Davis Monthan crash
For years I entered:
Newspapers.com is a subscription site but some local libraries allow free access with a library card.
Here is some information on the incident in Tucson, AZ Dec, 18th 1967.