I know for sure that the Air force World wide Model airplane Championships were held until at least 1971. These meets were held at an Air Force base, often in Texas but other bases across the country were used. The CL events were flown on the base, the FF events at a field nearby. Various commands would hold their own contests to select their 5 man teams to compete at the AF meet. Some commands did not send a 5 man team, some commands did not participate like SAC. TAC, PACAF, ATC, AFSC and MAC would send teams.
The Air Force meet was generally held two weeks before the Nationals so that a team could be formed and compete for the National Team Championship. The AMA used to have separate competitions at the Nats for a number of categories including National Team, Club Team, Open Champion, Senior Champion, Junior Champion. The National Teams and the Club Teams consisted of 5 competitors. The National Team members need not be affiliated with a club. The Club Team members had to be from the same club. Each member of a team could compete in as many as 9 events - 3 in CL, 3 in FF and 3 of any category. Points were gained as a percentage of the members' score/time/speed of the winning number.
As far as I know, the Air Force won the National Team Championship from the early 60's through at least 1970. I was on those teams in 1966 and 1970, though in 66 I was a "mechanic" which meant that I chased FF or stood in line for a team member's next flight in speed or FF, or worked in the hangar to repair broken airplanes. I did get to fly stunt (5th) since I won the stunt event at the Air Force meet earlier.
Sometime after 1970, it could have been 71 or 72, the Air Force Team at the Nats did not win. A group from the South figured out how the Air Force always won and did them one better. The Air Force teams consisted of 5 members but had 5 more mechanics for the duties described above. This gave a definite advantage to the Air Force teams as other national teams usually did not have the resources to support their team with many full time helpers. Also, the Air Force teams normally concentrated most of their events in FF. Yes, each team member had to fly at least 3 CL events, but relied on most of the team points to come from the 3 optional events to be in FF. The team from the South was made up of several Senior fliers, had plenty of help from families and friends, and concentrated most of their optional events in CL Speed where winning scores in the SR category could be more favorably compared. The Air Force Team got beat and then, there were no more Air Force World Wide Championships. This happened as early as 1971 but probably not later than 1973.
Sometime in that period, the AMA ceased their recognition of the various champion titles described above. There might not have been many or even any groups that would put together a National Team or Club team so interest apparently dwindled. The AMA did little to promote these activities and the model press also did little to recognize them. The Navy stopped hosting the Nats around that time and later the AMA went to multiple sites and different dates for various categories, it would become impossible to have such categories.
(This has nothing to do with the Air Force meets, but in the 70's, the AMA did have another category for Scale Champion, Jr, St and Open. Several events had to be flown including at least two of the three categories of CL, FF and maybe RC. This did not last long when the AMA went to multiple dates for the various events.)
I had heard that the Army and the Navy had entered the National Team category at the Nats, though not on a regular basis. The approach used by the Air Force was hard to beat until the team from the South figured it out.
The three Air Force meets I attended were well organized and well run capped by an awards banquet at the end of the week. They were really memorable events.
Keith