Browsing the history/documentary channels here in the UK (or the Hitler/WWII channels more like :rolleyes: ) I saw a few documentaries on aircraft that were cancelled at the prototype stages, in particular the Canadian Avro Arrow and the British TSR-2.
After cancellation, the governments who started the projects order the tooling for the aircraft to be cut up. In the case of the TSR-2, a later government was again interested in the project but gave up quickly as the costs to re-tool and start (effectively) from scratch were prohibitive.
Is there any reason given for this? All the documentaries mention is the end of the project and political meddling. It would seem useful to hold onto tooling to sell on for profit or keep for future use.
WAG, in times of war when some supplies, like various metals, are sparse, the tooling could be melted or reshaped and used for other projects that are in production.
Wasn’t the Avro Arrow project canceled because of suspected (or actual) Soviet infiltration? I seem to recall hearing that on a History Channel special, and it would certainly explain the destruction of the prototype tooling.
There’s also the possibility of espionage. From that POV, it makes sense not to keep the toolings (or even the prototype(s)) in existence any longer than absolutely necessary.
It has been alleged that Robert McNamara ordered the tooling for the SR-71 to be destroyed so it would not compete with his multi-service aircraft, the TFX (later known as the FB-111 Aardvark). The amusing thing about this theory is that it compares the fastest air-breathing aircraft, which was purpose built, with a flying brick that proved inept at everything except medium bombing (and later reconnaissance).
So there’s another (potential) reason: destroying the competition.
Large programs take on constituencies of their own, not only in industry but among the politicians in whose districts the jobs would be lost in the event of cancellation. It’s very hard for the government to actually kill a program it no longer needs or wants, and even if it succeeds it can be reinstated with enough pressure (the B-1 is a good example). Going beyond simply cancelling contracts to actually destroying the program’s ability to be easily restored is not an uncommon tactic by defense departments. The tooling ,being among the largest-cost, largest-lead-time, and hardest-to-replace items of a program, is a good target.
The Arrow and TSR-2, mentioned in the OP, were fine examples of programs that had become obsolete, or at least irretrievably out of control, well before their cancellations but had huge constituencies and inertias.
With regards to military aircraft, in some cases the government actually owns at least some of the tooling. This has been the case at Boeing in St. Louis. At least for some aircraft programs.