Many planes are parked
Aviation is an industry in crisis. War in Iraq and the outbreak in Asia of a severe pneumonia-like virus are merely the latest in a series of blows.
Many airlines have yet to recover from the effects of September 11 while many more are struggling with structural problems of their own making.
Since the start of the Iraq war many of the world's leading carriers have announced plans to cut costs, trimming flight schedules and/or laying off workers.
Their fear is that, as industry body IATA has warned, the war could add billions to the airlines' already huge losses and lead to a prolonged bookings and travel slump.
BBC News Online has this round-up of some of the announcements so far.
Delta said it was reducing its schedule by 12%, including on transatlantic routes.
Although the number-three US carrier made no announcement about staffing, it said it could not rule out job cuts in the future.
Northwest Airlines, the fourth-biggest carrier, is cutting 4,900 jobs and 12% of flights.
It blamed the action on a drop in passenger demand because of the threat, and now the commencement, of hostilities with Iraq.
And it warned that it might have to take further action depending on how the conflict with Iraq develops.
The world's biggest airline, American Airlines is cutting international flights by 6% in April and has warned that more cuts may be necessary.
Its domestic routes have already been slashed.
The firm is in a desperate battle to avoid bankruptcy.
Air Canada has filed for bankruptcy and is cutting 3,600 jobs from its 40,000 workforce.
There is speculation of a government bailout.
United Airlines, the second-biggest US carrier, has put thousands of flight attendants on unpaid leave during April.
Its chief financial officer has said that recent bookings have been down a "meaningful amount", while in February the company lost $367m - amounting to $13m a day.
There is speculation the firm might be forced into liquidation.
US number three carrier Continental Airlines is cutting at least 1,200 jobs to help cut costs by $500m.
Although European airlines face one of the toughest crises in history, the European Commission has said they cannot use the Iraqi conflict as an excuse to ask for financial aid from their governments.
The EU said governments would be allowed to help the airlines out when it came to paying for extra security measures, but it would not allow cash aid.
British Airways is to reduce capacity by 4% - about 130,000 seats - in April and May and bring forward plans to cut 13,000 jobs.
One of the seven Heathrow-New York daily return services will be suspended until the end of May and one of two daily Heathrow-Chicago return services will be cancelled until 8 April.
The London-Dubai route will see a reduced service and flights to Kuwait will continue to be suspended.
Other routes will see smaller planes being used.
Swiss International Air Lines, the successor to the failed Swissair, cut an order from Brazil's Embraer to 30 planes from 60, saving more than $700m.
Finnish carrier Finnair will cut some 10% of its 10,500 workers as it tries to save 160m euros (£108m).
Dutch carrier KLM is trimming capacity by 7% and has said it will cut thousands of jobs.
It also said it would introduce a war surcharge on routes to Asia and the Middle East for its cargo unit because of cancellations and re-routings caused by the conflict in the Gulf.
Lufthansa Cargo, the freight division of the German flag carrier, also plans to impose a "war risk surcharge" on all freight transported because of rising costs caused by the war.
Air France has said it will cut the number of flights it operates by 7%, starting in April.
Spain's Iberia will cuts its flights by 3% in April because of weaker demand for European routes.
Cathay Pacific, Hong Kong's main airline, has said it will cut 47 flights a week to eight destinations in Asia from mid-April because of weak demand.
Hong Kong has been at the centre of the outbreak of the deadly pneumonia virus.
State-run Air India has
increased its fares by 5% and added an additional fuel surcharge of $10 on each section of a journey.
Singapore Airlines, Asia's most profitable airline, said it would cut 60 flights a week because the virus outbreak had seriously affected air travel.
Singapore Airlines has now cut a total of 125 flights a week.
It slashed 65 flights a week last month because of the war in Iraq.
Australia's Qantas has laid off 1,000 workers temporarily, and cut 20% of its international flights, blaming the war in Iraq and the Asian virus.
Korean Air, South Korea's largest airline, has suspended flights to Dubai and Cairo and reduced flights to the US until the end of May.
Turkish Airlines said it had reduced the number of domestic and international flights as a result of sluggish demand.
It said passenger numbers and bookings had fallen 50% year-on-year since the start of war.
Kuwait Airways has suspended carrying passengers all over the world, except to Dubai and Cairo, because of the ongoing hostilities in neighbouring Iraq.