After a meeting at which the Federal Aviation Administration’s proposed airspace redesign plan was criticized Thursday in Washington, the group that monitors government spending decided to launch an investigation.

The Government Accountability Office, an independent, nonpartisan group that investigates how federal tax dollars are spent, has moved the controversial FAA plan ahead of other investigations and will start evaluating the efficacy of the plan immediately, according to U.S. Rep. Joe Sestak.

“Initially, they said they wanted to (start their investigation) in four months. Now they are convinced of the importance of this,” Sestak said. “They’re staffing it up right away.”

Sestak, D-7 of Edgmont, and U.S. Rep. Rob Andrews, D-N.J., whose districts cover the suburban neighborhoods surrounding the Philadelphia International Airport, met Thursday with four GAO employees who will oversee the study.

Sestak said it was “a challenge” to have the agency give priority to the case.

“You usually have to sit in line,” he said. “But this fit in with other investigations they are looking at with the FAA, and we were able to show the FAA has done this process wrong. It needs to come to a halt.”

The FAA plans to announce its decision of record in August, and have the implementation of the plan started by the middle of next year.

The redesign would change flight paths at the airport, bringing jetliners over the homes of several Delaware County neighborhoods. The goal is to maximize efficiency at the airport and reduce flight delays.

Residents have turned out by the thousands at informational meetings organized by the FAA. The public outcry was considered in the GAO’s decision, according to Sestak.

“The public should take a lot of the credit,” he said.

The plan was also argued to be flawed because the FAA could not provide a financial cost estimate for its implementation, the agency did not consider the effects of increased noise on the residents, and the best case scenario was shown to be a decrease of just three minutes in flight delays, Sestak said.

“We told them (Thursday), look at all the costs they don’t know: financial, health, education and a benefit, at most, of three minutes. Why are we doing this?” Sestak said.

Sestak credited a study sponsored by Andrews and himself, and the study conducted by Delaware County Council, as providing sufficient evidence for the GAO to start their own investigation.

The results of that study are not binding, but give Congress a tool it can use to “implement certain aspects of change,” Sestak said.

“We had to have enough evidence for an expert panel to say this was important,” Sestak said.

Meetings held with residents, coupled with the studies conducted by Sestak, Andrews and County Council, convinced other members of Congress to back the fight against the redesign.

The congressional backing was another factor taken into consideration by the GAO, according to Sestak.

“We’re hoping this is the beginning of the end,” he said.