If the long term plans of EDI or GLA would tell us all when one of them is going to build a runway capable of landing a fully laden cargo jumbo then I would be happy to see Prestwick being phased out or at least the loss making passenger part being shut down. Until that day dawns it remains a necessary Scottish asset.
Why necessary? Land it at MAN and truck it. Cargo cares not one whit where it lands.
How many fully laden flights are we talking about? Air France Cargo is closing down main body freighters so that leaves Cargolux with how many flights per week? 5-6?
If it COULD be developed as a Spaceport, for satellite, close orbit launches, then the business infrastructure surrounding Prestwick, with jobs, satellite and space development, just possibly could rejuvenate the whole area.
They couldn't even manage a Freeport against Shannon (who remembers that fiasco?).
It doesn't matter, no one will take tough decisions on this, it's too political especially with Sturgeon about to call
#indyref2. Unless the Nats can use Brexit as a last gasp excuse to get over the line, it's hard to see how they can win one once we've escaped the claws of the European Commission.
The hard decisions, well, let's kick that can down the road again. In the meantime, both GLA and EDI remain commercially viable and profitable airports competing against and continuing to beat a state owned PIK that continues to lose increasing amounts of money.