In the widespread relief that followed President Barack Obama and congressional leaders' compromise to avoid default and raise the debt ceiling, a large federal agency in dire need of funding was overlooked: the Federal Aviation Administration, which employs about 4,000 workers, has gone unfunded since July 23, nearly two weeks now.

The partial shutdown of the FAA will likely last through Labor Day, when Congress returns from summer recess. While their agency goes underfunded, dozens of airport inspectors told the New York Times that they had been told to charge all expenses to their personal credit cards for the time being. Over 90,000 construction workers are going unpaid while improvement projects at airports around the country are halted.

Air traffic controllers, who earlier this spring were under political attack after a series were caught asleep on the job, are paid from a separate fund and are still on duty, as are airplane inspectors.

“No safety issues will be compromised,” Secretary of Transportation Ray LaHood told reporters. “Flying is safe. Air traffic controllers are guiding airplanes. Safety inspectors are on duty and are doing their job. No one needs to worry about safety.”

The Associated Press reported that the government is likely to lose about $1 billion in ticket taxes — typically about 10 percent of each fare is turned over as tax to fund the FAA — during the shutdown. ABC News reported that for each week the FAA isn't on full duty, airlines pocket about $200 million from ticket fees — instead of ticket prices being lower due to the missing tax, airlines hiked up prices to rake in what usually would go on to the government.

Democrats attempted to pass legislation to reinstate the full operation of the FAA, but were blocked by Republicans.

“Republicans are playing reckless games with airline safety,” Senate Majority Leader Harry Reid said in a statement. “We should not let ideology interfere with making sure that Americans’ air travel runs as smoothly and safely as possible.”

Rep. Michael Michaud (D-ME), a member of the House Transportation and Infrastructure Committee, condemned the shutdown in a statement.

“I am deeply disappointed that the bipartisanship displayed on the debt reduction bill didn’t extend to the FAA measure,” he said. " None of this is good for the economy or the travelling public. It’s unbelievable to me that Congress took off without acting on this critical measure."