If there was any doubt about the extent to which low-cost carriers have encroached on traditional markets, EasyJet's successful entry on to the London-Moscow and Milan Linate-Rome Fiumicino routes underlines just how far things have moved.
Both routes are in the network carrier's heartland, the rights for both were hotly contested - and in the case of the 4h flight time between London and Moscow - are at the outer ends of the traditional short sector lengths that budget carriers enjoy.
"We concluded that EasyJet's proposal would introduce a distinctly different product into the market and would stimulate innovation on the route as a whole, as well as satisfying and stimulating consumer demand that is currently under-served," said Iain Osborne, UK CAA director of regulatory policy, in awarding the Moscow rights to EasyJet ahead of Virgin Atlantic last October.
In securing the rights for the much-coveted Linate-Fiumicino route, Italian regulators picked EasyJet over domestic rivals. While this reflects as much on the health of the Italy's beleaguered airline sector, it does demonstrate how the likes of EasyJet have challenged expectations around service and carrier nationality among passengers, and evidently, regulators.
"It's very much a coming of age for us in Italy," says EasyJet chief executive Carolyn McCall. "Italian business travellers are much more likely to consider us and it will have a halo effect on our Italian services."
Budget operators, however much the definition now stretches, are now part of Europe's airline hierarchy. Europe's top 10 low-cost operators carried 250 million passengers in 2012. The leading network carriers flew around 320 million over the same period. The different network structure means this is no apples versus apples comparison. But in pure bums-on-seats terms, it underlines the maturity of the model in Europe.
Neither are the ambitions of these low-cost operators so clear cut any more. The sicker network carriers from across the continent have become used to seeing growing numbers of orange and harp-adorned tails hoovering up any ground they give. But Vueling and Norwegian for example, typified by the latter's clutch of new routes linking Germany and Spain, are also evidently not constrained by serving only home markets.
Where the no-frills camp once adhered strictly to the model through which they first thrived, virtually all of them have now broken free to some extent. Be it allocated seating, serving business routes or selling through the GDS, Europe's budget carriers have evolved to increasingly appeal to business travellers.
"The point about evolution is it's forever and it keeps carrying on," says Peter Morris, chief economist at Flightglobal's consultancy Ascend. "So what you see is continually changing market environments and you are also seeing changing customer needs."
That market environment in Europe is now not just a mature one, but amid double-dip recessions, one of sluggish economic growth.
Such a climate has not tempered the optimism for growth ahead though. Ryanair and Turkish carrier Pegasus Airlines have joined Norwegian in securing aircraft for future expansion, while EasyJet and Vueling are closing in on fleet decisions. The key question is where airlines will put these aircraft.
"You simply can't measure how full Europe is," suggests Morris, saying the notion of how much opportunity there is to grow in a mature market like Europe is dependent on the next step in cutting costs. "The first big jumps have been made," he says, acknowledging that it is harder to go from 12h to 13h flight utilisation than from 8h to 9h.
That is not to say the sector in Europe has it all its own way. It too faces challenges, as the failure of Bmibaby shows. But their continued advances have kept up pressure on network carriers on short-haul routes.
"The structural instability across the industry is forcing legacy airlines to rethink their models. They're floundering trying to find one that works," said aviation consutlant Rigas Doganis at the recent Airline Business Technology and Innovation in Airline Distribution conference. "We've seen legacy carriers restructure their network - generally speaking reducing short-haul, moving out of markets where they cannot compete effectively with low-cost carriers."
But a decade after European carriers tried to counter the low-cost threat with in-house budget units, the big network airlines have turned again to separate short-haul operations. Iberia Express, Germanwings and Transavia have all found roles, or enlarged parts, in network carriers' attempts to tackle short-haul.
Experience has played its part in the new units. The moves seem less about mimicking low-cost rivals and straying into non-core markets, and more to do with addressing the structural changes in the short-haul market. Iberia Express tackles its parent's uncompetitive short-haul flights at Madrid, while the revamped Germanwings is Lufthansa's solution for its non-hub services.
EasyJet's McCall believes the moves are part of a "reconfiguration" of existing capacity. "Germanwings is Lufthansa with different clothes on," she says. "Its going to be interesting how things pan out. They have tried all sorts of things. But as far as we are concerned, we are competing against Lufthansa in Europe."
Network carriers have so far broadly managed to navigate, relatively unscathed, the choppy waters of labour relations involved in securing the necessary lower operating costs. However, work remains to be done.
Iberia, for example, secured job cuts and large salary reductions with its unions after a deadlock involving two five-day stoppages. But pilots' union SEPLA is still not on board - the two sides are divided on the legal significance of the union's refusal to sign up to the mediator's agreement - while expansion of Iberia Express is blocked at the moment by a dispute over labour rules.
"Iberia Express has been a fantastic success and demonstrates what can and should be done in the short and medium-haul market," says Willie Walsh, chief executive of Iberia's parent IAG. "In the absence of being able to expand Iberia Express, there will be no expansion of the Iberia short- and medium-haul operation. And quite the opposite, there will be reduction in Iberia short-haul."
The airline, launched last March, carried just under 3 million passengers in its first year of operation. While the legal wrangles over labour rules continue, Walsh notes: "These restrictions end at the end of 2014, so they should be seen as a temporary restriction on what we can do with Iberia Express."
Morris believes that for network carriers dealing with the low-cost threat, it is a bit like the grieving process. "You have denial, anger, bargaining, depression and acceptance. In some markets, you are very nearly in the world of acceptance - for example in the US. Different regional markets are in different stages. You have everything from the immediate denial moving through those different stages," he says, adding, "I think quite a few are currently in that stage of depression."