James: What I say may not mean much. I am not a formal VSO. But, I will tell you what I did. I had most of my military records, military health records, a copy of my performance reports, buddy letters, and maps showing how close to the perimeter I worked. I sent a copy of Army Field Manual 3-3. The manual states that herbicides will drift up to 500 meters from where they are sprayed. I don't know if the VA uses that manual. That drift area would have covered the Takhli RTAFB Flightline, End of Runway, Trim Pad, Bomb Dump and many other areas. In addition, to the above, you will need a record that says you were assigned to Takhli RTAFB as an Auto-Pilot Tech. You must explain your duties, where you worked and what you did. Ie. Flightline Repair of Aircraft, End of Runway Checks, Trim Pad Work etc.etc. Get Buddy letters if possible. I was there in 1970 as a Flight Chief in the 44th TFS. I will write a letter if you can send me something that shows you worked the aircraft. Do you have all of the above records? The VA will get some records, but I don't trust the system to get all that you need. Get everything you need up front. Do you have a good VSO? Most VSOs do not have the time, and do not spend the time required to put everything together for a fully developed claim. You will need to put everything together yourself. Then take it to the VSO for submittal. Before you file your claim, ask yourself, if you were a VA Examiner and you received your request would you approve the request? If not, then you need more proof.