Low-cost airlines have shrugged off analysts' concerns that tough restrictions on carry-on baggage introduced in the wake of last Thursday's terrorist alert could threaten their business models if they are made permanent - and have insisted the industry will continue to thrive just as it did after 9/11.
A new regime introduced by the Government on Monday limits passengers' hand luggage to one small cabin bag no bigger than 45cm by 35cm by 16cm - the size of a small laptop case. Airlines expect the new rules to remain for the foreseeable future.
The allowance is less than half the size travellers were able to take on board before last Thursday's foiling by police of an alleged plot to blow-up planes flying between Britain and the US. Liquids and aerosols, including toothpaste, shaving foam and deodorant, have been banned from all hand luggage indefinitely.
Over the last couple of years the no-frills players had been encour-aging passengers to carry more hand luggage, enabling them to make savings on baggage handling charges and improve aircraft turnaround times. These have been cut to just 25 minutes for Europe's biggest two no-frills carriers - Dublin-based Ryanair, which flies 351 routes across 23 countries, and Luton-based easyJet, which flies 267 routes across 21 countries.
Indeed last March, Ryanair moved to discourage passengers from checking in baggage for the hold at all by introducing a fee of 3.50 euro per bag if booked in advance on its website or seven euros per bag if presented unbooked at the airport. The initiative mirrored an earlier move by smaller rival Flybe.
EasyJet had resisted introducing charges for checked-in baggage but was understood to be considering it.
Analysts fear continuing restrictions on hand luggage will mean more baggage shifting to the hold and hence higher ground handling costs and extended turnaround times.
"It will be interesting to see how this evolves but certainly the market is starting to think there could be some pressure on their business models," said one. "They can't start hitting everybody with a charge for hold baggage when passengers don't want to put it in the hold but are being forced to do so by the Government."
Analysts are also worried the new restrictions could significantly hit demand from the business community as the days of travelling with just a suit carrier and a briefcase could be over.
But the no-frills airlines regard such talk as scaremongering.
"All the same people who predicted the death knell of low-cost airlines after September 11 are predicting the death knell of low-cost airlines now, purely because we can't take such big handbags on board," noted Toby Nicol, easyJet's head of corporate communications.
"The low-cost airline model is significantly more robust than that."
Mr Nicol explained that the fundamental components of easyJet's business model are based around the quick turnaround of aircraft, the efficient use of resources with no waste, selling direct to consumers, not providing connecting flights, high load factors and yield management.
"Those are the pillars of the low-cost airline model, it's nothing to do with baggage," he insisted.
He said the assumption that the new restrictions would inevitably lead to a greater volume of bags going into the aircraft hold is critically flawed.
"Why not incentivise passengers to take a single piece of hold luggage so you might actually end up with less," he asked. "Or you find a way of charging for baggage which incentivises people. Anything is possible.
"We're going to come out of this pretty well, I can absolutely guarantee that."
Ryanair's Peter Sherrard was similarly dismissive of analyst fears and insisted the carrier has no plans to re-think its policy of making passengers pay to check-in luggage.
"The idea of charging for baggage is to reduce the amount of baggage people carry," he said.
And if, in the short term, the new rules mean more luggage in the hold the airline will cope. "It's very simple to load more bags into the hold, it doesn't take any additional time to do it," he argued. "And the increased revenue from this will offset the costs."
He also stressed the international nature of Ryanair's business, noting the vast majority of the 113 airports it operates to throughout Europe have had little or no disruption since Thursday.
Consequently Ryanair will not be adjusting its pricing strategy. "The average fare last year was £28 and we've already told the markets that we don't think it will change significantly in the current year," said Mr Sherrard.
Meanwhile, analysts are continuing to tot-up the costs airlines are estimated to have incurred since Thursday. They reckon Ryanair and easyJet's bill will likely be about
£10 million each, with British Airways facing a £50 million hit and Virgin Atlantic some £15 million.
The airlines want BAA, the operator of seven UK airports, including Heathrow, Gatwick and Stansted, along with the Government to make a contribution.
They have been critical of the handling of the crisis by BAA, recently acquired by a consortium led by Spain's Grupo Ferrovial, maintaining it was not prepared and failed to provide enough staff to carry out the extra security checks.
Analysts believe the airlines have a case but believe some of their criticism is brinkmanship given that the Office of Fair Trading is currently investigating BAA's dominant position in London.
But it seems some passengers are already losing patience with the budget airlines, especially as luggage has gone missing in droves.
David Jones, of Montague Capital in Stratford-on-Avon, yesterday launched a scathing attack on Ryanair, particularly over safety.
He charged: "Ryanair has once again shown that profits matter more than passenger safety, calling for a return to the woefully lax security standards in place before last Thursday.
"This is a little odd, given that BlarneyAir had led the way in trying to charge extra for carrying hold luggage. It's not as if it wasn't already making a handsome return on that little scam.
"The truth is that, like BAA, it probably hasn't employed enough people to handle the extra workload. If no carry-on baggage is allowed, turnaround times ought to improve, were it not for the fact that the extra volume of hold luggage cannot be handled quickly enough, which actually lengthens turnaround times and makes the Ryanair timetable fall apart at the seams.
"Ironically customers of the legacy carriers ought to be grateful. The likes of BA were already set up to handle proper luggage. Considerate passengers will no longer have to tolerate the efforts of the inconsiderate to stow a surfboard in the overhead lockers. Oh, and there's the added bonus of a lower risk of being blown out of the sky."
There have been murmurings that the airlines might take legal action against BAA and possibly the Government for compensation.
But British Airways and easyJet both denied that they and other airlines, including Ryanair, were planning to sue the Government for up to £300 million to recover losses incurred over the extra security.
"No consideration has been given or is being given to suing the UK Government," said a spokeswoman for BA. She confirmed BA will seek compensation from BAA.
A spokesman for easyJet also dismissed the claim. "Any suggestion that easyJet is considering suing the UK Government for any losses incurred as a result of the additional security measures imposed last week is wildly and deliberately inaccurate," he said.
"The first duty of any government is to protect its citizens and easyJet commends the UK Government for acting decisively last week."
However, the spokesman did note that the situation of the last few days has highlighted the "absurd and immoral" obligation of airlines to provide hotels for passengers when flights are cancelled for reasons outside their control.
