I am reminded (by the image a couple of posts up of the gormless 1980s has-been "personality" Anneka Rice getting a part in the Jubilee programme) of how the BBC (and other broadcasters) work nowadays.
The programme is approved, and it becomes known that there is a budget of say £300k for it. There are myriad personalities, all represented by an equally myriad labyrinth of agents, who all say on learning of any budget "that's mine", and launch into an overwhelming, not to say murky, lobbying routine of the relevant production staff. The agents have no interest in whether their client has any ability for the programme, they just want the job for their person, and their percentage. If they can stick one over on the production team, so be it. Their person shows up, they get the money. If they're useless, pocket the money and on to the next person they represent.
Anyone who understands aviation, the military involved, etc (getting back to subject) probably doesn't have an agent and so gets nowhere near any of this. There are also BBC staff who just won't consider anybody contributing who doesn't have an Equity card.