The last time passengers abandoned airlines in such large numbers was in the wake of September 11 2001, when the public developed an instant fear of flying.
PASSENGERS
The last time passengers abandoned airlines in such large numbers was in the wake of the September 11 terrorist attacks in 2001, when panic over security created an overnight fear of flying among the public.
Aviation experts say the reaction to the UK's ongoing economic turmoil has been less sharp but is likely to be longer and potentially more damaging.
Unlike with the bounce-back that followed the attack on the World Trade Centre, the problems now faced by airlines and holiday firms show little sign of evaporating in the immediate future.
As people face further job cuts, repossessions and economic insecurity in 2009, they are less likely to find money to spend on an overseas holiday, while businessmen are also less likely to fly to meetings, analysts say.
The Association of British Travel Agents (Abta) said it was seeing increased interest in travel within the UK.
"The Scottish tourism market is more interested in camping and caravanning within the UK. There is a pressure on airlines as a result," said spokeswoman Francis Tuke.
According to one industry source, growth in aviation follows growth in GDP. "It's pretty much follows the same curve. When you see an economic downturn, you'll see a corresponding fall in air transport passenger numbers," he said.
By that reckoning, airlines can expect to wait until at least the second half of 2009 - some analysts think a lot longer - to see passenger numbers start to recover from the rot that set in last summer, when a combination of record oil prices and the onset of the credit crunch prompted industry-wide panic and the collapse of holiday firms XL and Seguro Holidays.
BAA, which owns Glasgow, Edinburgh, and Aberdeen airports in Scotland, has seen passenger numbers fall steadily since August. In November, the last month for which figures are available, there were 20,522 fewer passengers, a drop of 3.3%. Glasgow Prestwick and Inverness Airport have also seen passenger numbers tail off, though less dramatically.
Among charter flights and domestic routes, the drop in passengers has been most pronounced. Services to Heathrow from Edinburgh and Glasgow - the two most popular routes in the UK - dropped by 7.5% and 4.6% respectively between January and October 2008, compared with the same period in the previous year, according to transport consultants RDC Aviation. At Prestwick, passengers on non-scheduled flights in November last year were down nearly 90% compared to November 2007.
DESTINATIONS
Despite the immediate crisis, aviation experts are still predicting long-term growth in aviation in Scotland, driven by continuing consumer demand for cheap scheduled flights to international destinations. The thorny question concerns what happens in the short term.
So far, airlines and holiday firms have responded to the downturn by cutting the volume of flights, with non-profitable routes being cut or reduced. BAA, for instance, saw a 3.2% drop in the number of flights at Scotland's biggest three airports in the year to November 2008, compared with the previous year. Charter operators are estimated to have cut by around 15% the number of seats provided in 2008.
Though routes come and go, with more flights over the summer months than over winter, a look at the destinations served in October 2008 and October 2007 provides a snapshot view of how airlines and holiday firms are reducing their services.
Data recorded by the Civil Aviation Authority (CAA) show that there were 40 destinations flown to in October last year, including scheduled and non-scheduled flights, that were not flown to a year earlier.
But 56 of the October 2007 destinations disappeared from some of the Scottish airport lists by 2008. They included Toronto, New York, Athens, Naples, Oslo, Warsaw, Prague and Dublin.
AIRLINES
There are concerns over the impact this will have on holiday companies and carriers, as well as the wider impact on the Scottish economy.
Michael O'Leary, chief executive of Ryanair, has predicted that the recession will leave only a "big four" list of airlines operating in Europe - British Airways, Lufthansa, Air France-KLM and Ryanair - with smaller companies either going to the wall or being taken over, although others have dismissed this as a pretext to talk up a proposed takeover of Ryanair's rival Aer Lingus.
A spokesman for British Airways also expressed concern over the crisis in aviation. "We are facing the most challenging trading environment in the history of aviation and we must take every measure to ensure that every part of our business is operating viably," he said.
Ms Tuke said she remained optimistic that the economic climate hadn't "dampened the appetite for tourism" and there was cause for confidence in the aviation industry.
She said: "Airlines have taken precautionary measures rather than being forced into an unpleasant situation. There will be a slight downturn but it does seem to have been on the travel industry's terms at the moment.
"No-one is under any illusions that 2009 is going to be a great year for travel.
"Everybody is aware we're going to go through harsh times. But travel is less affected than some industries like housing, the automobile industry and construction, which have been very hard hit."
Not all airlines have been similarly affected. In fact, some are doing rather well. That's because, while charter flights are undergoing a long-term decline, the preference for scheduled flights to foreign destinations has remained strong - even in the face of the economic downturn.
Ryanair, for instance, boasted last week that it had seen an 18% growth in passenger numbers in 2008 after a massive expansion in its services, and is planning to introduce "aggressive" price cuts this year, which are likely to put further pressure on competing airlines.
Low-cost competitor Easyjet has also seen an increase in passenger numbers, to 3.1 million in December, 7.3% ahead of the previous year.
The Luton-based airline's load factor - a measure of how full its plane are - rose to 82.3% from 78.9% Scots-based Flyglobespan, which has cancelled three routes from Aberdeen and replaced one over the past four months, said it nevertheless planned to put on five extra destinations in the summer and anticipated strong customer demand for them. Chief executive Rick Green said the airline was offering a diverse choice of destinations amid a "challenging" year for the industry.
A spokesman for BMI said it had kept the same number of Scottish services over the past two years, with London Heathrow to Inverness suspended last summer and a new service from Edinburgh to Zurich launched the summer before.
Flybe, meanwhile, said it had seen a "net gain" of 18 routes over the past two years.
BA, which has up to 49 return services from airports in Scotland to London a day, has faced criticism for pulling its 6am Glasgow to Heathrow service but has expanded its services from Edinbugh and Glasgow to London City airport.
AIRPORTS The owners of Scotland's main airports have also expressed optimism.
A spokesman for BAA said: "In the long term, our forecast continues to show growth. It's not changing the long-term forecast. We're still investing on that basis of long-term growth."
A spokesman for Glasgow Prestwick Airport added: "The loss of major customers such as Atlas/Polar and Seguro had a significant effect on the business in 2008 but we are actively trying to fill the gap left by these operators and are confident we can do so.
"We expect 2009 to be a difficult year but aviation has shown in the past that it can survive hard times."
Routes withdrawn
In October 2008, compared with October 2007 - Includes scheduled and non-scheduled flights, including some private
- GLASGOW INTERNATIONAL TO:
Calgary, Ottawa International, Vancouver, Pula, Tarbes-Lourdes International, Tbilisi, Dusseldorf, Hanover, Mumbai, Shannon, Milan (Malpensa), Palermo, Lisbon, Almeria, Gerona, Stockholm (Arlanda), Kiev (Borispol), Boston
- EDINBURGH TO:
Hamilton (Canada), Toronto, Billund, Alghero, Bergamo, Verona Villafranca, Gdansk, Katowice, Poznan, Warsaw, Dnepropetrovsk, New York (JFK)
- ABERDEEN TO:
Zagreb, Vagar, Athens, Naples, Kristiansand (Kjevik), Kristiansund (Kuernberget), Oslo, Krakow, Funchal, Murcia San Javier, Vigo, Dnepropetrovsk
- PRESTWICK TO:
Kaunas, Amsterdam, Lisbon, Alicante, Barcelona, Dalaman
- INVERNESS TO:
Prague, Copenhagen, Athens, Dublin, Alghero/Sassari, Milan, Naples In October 2008, compared with October 2007* * Includes scheduled and non-scheduled flights, including some private
