Two were needed so that two crews could be validated - as if the whole notion wasn't already ludicrous enough.
Don't need to Google Derry - that's precisely the kind of nonsense that has got us into this situation in the first place. All that needs to be done is to set-out precise rules (and preferably rules that aren't as ridiculous as the ones we currently have), and then expect pilots to stick to them. What's the point of a validation display if the public appearance isn't precisely the same? The whole idea is ridiculous, because no matter how many validations are flown, there's no guarantee that the actual display will match it.
But regardless of Farnborough's silly rules, they obviously shouldn't apply to an aircraft that requires so much public funding. It wouldn't have hurt Farnborough's "experts" to simply go watch a display somewhere else and make a validation judgement on that. Or just grow-up and accept that the Vulcan crews know what they're doing and don't need to be second-guessed by anyone.
Either way, it's unfair to expect fuel, fatigue and engine life to be wasted on two displays that are patently unnecessary. It's even more offensive to not even pay for them. If Farnborough wants to impose rules then they should expect to pay for them.
Can't help feeling that Farnborough has a slightly over-inflated option of itself. Obviously it was once a hugely important world event, but maybe they ought to accept that business and commercialism aside, the actual flying display barely raises an eyebrow now.They ought to be grateful that they've got the Vulcan and be using some of their huge revenue to pay for it, not just some of it.