With the Boston bombings fresh on her mind, Cathy Critser of Summerville said she was terrified Wednesday when a small plane swooped over her on the Arthur Ravenel Jr. Bridge.

“It scared the daylights out of me. I thought he was going to run into the bridge,” she said.

The plane was a Charleston County mosquito control aircraft operating within established guidelines, the county said.

On Wednesday, Charleston County Mosquito Control Division's aerial contractor, Williamsburg Air, was conducting a standard flight near the Ravenel Bridge, the county said.

“The plane was operating within the FAA guidelines, which enable us to exist in a restricted category so we can fly low to treat mosquito larvae,” the county said in a press statement.

Critser said the plane came toward her from the downriver side of the bridge as she was traveling northbound before reaching the towering overhead support cables.

She thought the aircraft would hit street lights on the Charleston side of the bridge. Drivers were pulling over and stopping on the span because of the aircraft, she said.

“This plane looked like it was coming right at us,” she said.

After passing over the bridge, the pilot headed toward a tree line, which Critser thought the plane might hit. She called 911. She said that she was told many others had called about the same thing.

The incident happened at about 3:30 p.m., she said.

Guy McClary, owner of Williamsburg Air, said no one was in danger because of the aerial spraying operation in the area of the bridge, which has happened twice before this year without complaint.

“Everything that's going on in this country, I can understand people being concerned,” McClary said.

He said the plane was 300 feet above the bridge.

“We're high enough across that bridge,” McClary said.

Williamsburg Air has contracted with the county for aerial mosquito control for seven years, he said.

The plane was near the bridge while treating both ends of Drum Island, a spoil area that is a notorious breeding ground for mosquitoes, the county said.

“It's important to emphasize that the pilot was not doing a 'fly-by' over the bridge, but was following normal protocol within our safety guidelines in order to conduct targeted mosquito treatment,” the county said.

Under protocol, the county notifies police in advance that such a plane will be in their area.

“This is all part of a very detailed and routine process to keep the mosquito population in Charleston County under control,” the county said.

YouTube video by Ted Childress (used with permission):