"How can they possibly survive?" Eighteen months ago, aviation industry blogs, forums and trade newspapers were awash with variants of this question as writers discussed the fledgling transatlantic business-only airline sector. It wasn't just anecdotal accounts of aircraft flying near empty that fuelled the speculation. Industry watchers were doing the sums, taking the monthly air passenger statistics for Stansted—from where the new business airlines, Maxjet and Eos, fly—dividing them by available seats and coming up with (shared) average load factors ranging from 22 to 35 per cent—not enough to sustain a viable airline.

Today, the picture is very different. With load factors up to 65-75 per cent (which includes new entrant SilverJet flying from Luton), suddenly business-only is the hot ticket, accounting for almost a fifth of business-class traffic between the UK and the US.

So what caused the turn-around? In part it's down to an overall increase in business travel, but also to a growing enthusiasm for what the new business-only airlines offer. Senior VP for planning and development Josh Marks says Maxjet's success is due to location, location, location—or put another way "the fact that it's not Heathrow". Business travellers, particularly from the City, find it easier to get to Stansted, says Marks, and quicker to get through it. Meanwhile, US transatlantic travellers are realising they can do their long-haul leg in comfort and style, and then hop on any one of Easyjet's or Ryanair's flights to Europe.

It's an opinion shared by SilverJet CEO Lawrence Hunt, who shrugs off the idea of competition from legacy airlines like BA and Virgin (which are considering their own business-only products), explaining that what counts is the whole end-to-end experience. SilverJet's "dedicated" terminal at Luton is a winner, he says, with 90 per cent of the airline's customers critical of Heathrow.

Dave Simmons, CEO of search engine BizClassTravelMarket.com, believes the sector has room for more growth with airlines eventually adding other long-haul routes, starting with South Africa. Ultimately, he says, we'll see airlines mirroring hotels: some will be five-star, some will be three-star.