Washington (CNN) - The U.S. Senate went on summer recess Tuesday night without taking action to fully fund the Federal Aviation Administration, all but assuring that almost 4,000 furloughed FAA workers will remain jobless for the next five weeks and preventing the agency from collecting $1.2 billion in aviation taxes.

The only sliver of hope for furloughed FAA employees and laid-off airport construction workers rests with the fact the Senate scheduled nine "pro forma" sessions during their break, giving the Senate opportunities to consider the funding bill. But Senate leaders gave absolutely no indication they would do so.