The buzz of rescue crews and TV cameras flying helicopters overhead the Hurricane Harvey disaster zones have become familiar noises, but planes with a different purpose have been flying above flooded neighborhoods as well.

Louisiana's Civil Air Patrol has been flying over the southwestern part of the state and capturing photos that are helping the Governor's Office of Homeland Security and Emergency Preparedness determine the extent of floods that swamped some coastal areas.

Four Civil Air Patrol flights — each manned with a pilot, observer and photographer — circled above Cameron and Calcasieu Parishes as some people on the ground fled to shelters after rising floodwaters forced them out of their homes.

The Civil Air Patrol is an auxiliary for the U.S. Air Force, which provides their planes. Those who fly are volunteers. Some are military veterans, while others are commercial pilots or hobbyists who simply enjoy being in the air. Search and rescue work is their "bread and butter" on a day-to-day basis, said their Louisiana Wing Chief of Staff, retired Lt. Col. Amos Plante.

But during natural disasters, these fliers are frequently called in to photograph, rather than help with search and rescue. Plante has helped with flights in the past to photograph the devastation from Hurricane Katrina, the 2016 Baton Rouge floods and at other times when weather disasters struck the state.

"They take pictures of targets that they deem to be damaged and affected by the flood and the rain," Plante said. "They're looking for places where human life is at stake."

Mike Steele, the communications director for the Governor's Office of Homeland Security and Emergency Preparedness, called the Civil Air Patrol a "fantastic asset" during crises like Harvey.

Law enforcement usually feeds GOHSEP information on where flooding might be the worst, and that is then used to direct the Civil Air Patrol on where to take photos.

Some of their recent photos captured the extent of Harvey's flooding in the Grand Lake community in Cameron Parish and along a saltwater control structure north of Lake Charles.

"We either love flying or want to contribute back to the community and this is our way to do it," Plante said.

Follow Andrea Gallo on Twitter, @aegallo.​