One of the oldest flying aircraft in the US air force is the bomber B-52 Stratofortress, built during the 1950s. Over 700 of them were built during a decade with only above 70 today being used in the active or reserve forces. The retired ones are either in museums or in The Boneyard.
During the visit to AMARG, the guide explained us one historical anecdote taking the following picture as the departing point:
The curiosity of the picture: as you can see the aircraft has no horizontal tail plane (HTP).
The story went as follows: as part of Arms Control and Disarmament agreements between the USA and USSR, the USA had to retire a certain number of B-52 aircraft from service (over 300 of them). At some point a soviet delegation visited The Boneyard at Tucson to witness the retirement of those A/C. However, they said that being the AF base right there, side by side of the boneyard, the USSR could not have any guarantee that those B-52s would not be immediately put back into active service just after the soviets had left the city, and thus required that Americans dismantled the HTPs from all B-52s that were to be retired as part of the agreements. In that way they could always check via satellite image whether they had those HTP on or off…
Later on I checked the story in the Wikipedia where you may see the whole background of the START agreement. Some of the aircraft were chopped into 5 pieces. Those you cannot see in the guided visit to Davis-Monthan AFB but you can see them in satellite image here: