Mistakes by air traffic controllers put planes too close together in the sky 10 times in just 30 days recently at DFW International Airport.
Those controller errors prompted the Federal Aviation Administration to temporarily suspend on-the-job training of some new controllers at DFW Airport last week.
An FAA memo to controllers obtained by NBC5 said, because of the recent errors, "...we must stop and regain our focus."
The Union that represents air traffic controllers said training of new hires has become a distraction at DFW, where more than one-third of all controllers are now in some level of training.
"We're at the point in the tower where that's about all you do is train. We can't train this number of people all at once," said Rick Loewen, Union spokesman. "It's crazy."
The FAA said the majority of errors have been made by fully certified controllers, and not trainees.
In a statement the agency said, "We continue to work with all staff to determine the causes of these events, and to work toward continued error reduction."
Monday marked the start of one of the busiest travel weeks of the year.
Told of the recent controller mistakes, airline passenger Kim Huskey said, "It scares me. I'm not a great flier to begin with and it sure doesn't put a lot of confidence when you hear things like that."
