“The worst sort of business is one that grows rapidly, requires significant capital to engender the growth, and then earns little or no money. Think airlines.” Last week half a dozen carriers demonstrated the truth of Warren Buffett’s words by going bust – and showed in the process that neither “all-business class” nor “low cost, long haul” operating models are immune to the airline industry’s deadly economics.

This week has seen the collapse of Oasis Hong Kong, which offered cheap fares to London and Vancouver, and of a cluster of US airlines, from Skybus, a start-up low-cost, short-haul carrier, to Frontier Airlines, a discount carrier that flies out of Denver. Silverjet, an all-business class airline in the UK may be taken over, following the demise of rival Maxjet last December.