For the past week, military helicopters have been swarming the skies over Dallas-Fort Worth, often in formation.

Preshelle Clay from Garland noticed the aircraft and asked Curious Texas: "Tuesday, March 26 just after noon, I saw six solid black unmarked helicopters flying fairly low and in a group over Garland. Why?"

Clay wasn't the only one who was puzzled by these choppers.

Jorje Cruz from Irving also asked Curious Texas about the helicopters flying over Irving since Sunday. We were unable to get in touch with Clay or Cruz after their initial questions, but we attempted to satisfy their curiosity.

Their questions were submitted as part of Curious Texas, an ongoing project from The Dallas Morning News that invites our readers to join our reporting process. The idea is simple: You have questions and our trained journalists can find the answers.

As it turns out, the helicopters aren’t unique to Irving, though its residents have been ever-present on social media. They’ve been flying over most of the Dallas-Fort Worth metroplex for two weeks now.

Irving police said the flights are part of a routine training exercise being conducted by the Department of Defense in conjunction with local law enforcement.

The drill began March 18 and ends Saturday, after which local residents are likely to see far fewer helicopters buzzing over their cities.

Irving police tweetedThursday morning that the helicopters were part of a routine training after they said officers saw residents' many questions on social media.

There have been many questions & posts surrounding the military helicopters that have been seen flying around Irving. The Department of Defense is conducting a routine training in the DFW area until March 30th. pic.twitter.com/r3lR3MaOPg — Irving Police Dept. (@IrvingPD) March 28, 2019

We spoke with Cmdr. Pat Coffey, operations officer at the Naval Air Station Joint Reserve Base in Fort Worth, to learn more.

Coffey said the helicopters are flying over residential areas to address a specific need, one that calls for a specialized operation. He did not disclose what that need was, citing safety concerns while the drill is ongoing.

Coffey said that some areas like Irving may be seeing more flights because of how resources are allocated.

He said military officials are aware that the flights cause concern, so they will communicate with areas around bases and local homeowners' associations to notify residents of the routines.

"There are operations that have to be conducted and that are potentially going to make folks aware, so what happens is meetings months in advance," Coffey said. "Government agencies, including civil authorities, are notified and in agreement."

Coffey said he values the relationship the military has with people living in Dallas-Fort Worth, and would do nothing to jeopardize their trust.

The helicopters fly out of multiple bases around the area, Coffey said, including his in Fort Worth.

The Department of Defense did not allow any media or public viewing of the event for safety reasons.

More from Curious Texas

Tell us:

What do you wonder about the culture, people and institutions of North Texas -- and the rest of our great state? Help us investigate stories that matter to you.

No question is too big or too small. Let's get started!