Despite budget cuts, TSA is increasing checks after Brussels bombing

American Airlines joined a list of critics blasting the Transportation Security Administration (TSA) for long lines, closed checkpoints and missed flights yesterday, when it branded the organization's service 'unacceptable' and said it had gotten 'exponentially' worse.

The remarks came after it was revealed that a shocking 6,800 of the airline's customers had missed their Spring Break flights in just one week last month, NBC reported.

'The lines at TSA checkpoints nationwide have become unacceptable,' American spokesman Ross Feinstein said in a statement Wednesday.

'Unacceptable': The TSA's service isn't up to scratch, according to American Airlines, which blames the struggling authority for 6,800 of its customers missing flights last month due to waits of more than an hour

Troubled: The TSA has been fighting budget cutbacks, and has had to close some checkpoints - while at the same time wanting to increase security in the wake of the Brussels bombings

As a result, he said, 'our customers are waiting in TSA lines greater than one hour.'

And the company is 'concerned that these lines will grow even longer,' as 2016 moves out of the traditionally quiet early period and into summer.

It's not just airlines that are troubled by the long lines caused by TSA checkpoints.

Both Seattle-Tacoma International Airport and Hartsfield-Jackson International Airport in Atlanta have said they may get private security contractors to replace the authority, NBC says.

In a February letter on WSBTV, Hartsfield-Jackson's general manager called the organization 'woefully understaffed'.

And Seattle-Tacoma has already hired extra security staff with a view to dropping the TSA altogether, CBS Baltimore said.

The TSA has been under attack on a series of fronts lately, with budget cuts leading to reduced staff and checkpoints being closed, the station reported.

Despite this, the authority said last week that it planned more security checks in the wake of the Brussels bombing, and warned of even longer waits.

'This is one of the highest-volume travel years we've ever seen,' TSA administrator Peter Neffenger told reporters, according to the Washington Post.

'That means we're going to have lots of people moving through the airports,' he continued.

'Get to the airports early, because even if I can move you efficiently through the line, you're still going to find long lines there.'

'Concerned': American Airlines spokesman Ross Feinstein (left) is 'concerned' that the TSA can't handle the summer rush of holidaymakers. TSA head Peter Neffenger (right) warned people to get to airports 'early'

The TSA has requested money to hire 300 more screeners, NBC said, a tiny 0.7 percent increase on its existing 42,525 workers.

It also plans to use sniffer dogs to check entire lines of passengers for explosives, and increase overtime scheduling for existing staff.

This isn't the only bad press the TSA has encountered lately.

Last week it emerged that it had paid $47,000 for an app that randomly told passengers to walk either left or right - something that developers say could have cost just $20 to make.

And last summer the TSA's acting head was ousted after 95 per cent of undercover Homeland Security agents made it through security carrying weapons and fake explosives.

The authority says that it has tightened up operations since that test.

The 6,800 passengers who missed their flights last month were affected from March 14-20, during Spring Break, American Airlines said.