MIDDLETOWN, Calif. -- A Cotati man has been identified as one of two pilots killed when their planes collided in midair over Lake County late Saturday morning, authorities said Monday.

The crash happened at about 11 a.m. as both pilots, one flying a Schleicher glider and the other in a single-engine Piper Pawnee, were headed for Crazy Creek Gliderport in Middleton, Calif., Federal Aviation Administration spokesman Ian Gregor said.

The pilot of the glider has been identified as 63-year-old Harold Harvey Chouinard of Cotati, Lake County sheriff's Capt. Jim Bauman said.

Bauman identified the other pilot as 44-year-old Robert Sean Boylan of Lake County.

Gregor said the FAA and the National Transportation Safety Board are investigating the crash.

“There were a couple eyewitnesses at the scene. It appeared they were both trying to use the runway at the same time and didn't see each other,” said CAL FIRE Battalion Chief Rob Sonsteng.

Paul Franklin, a local pilot who also had been towing gliders up that morning saw the crash happen.

“I was helping the gliders launch and having a conversation with people here and saw the accident,” said Franklin. “Both aircraft just collided -- spun down.”

Sonsteng was one of the first responders on the scene.

“The same time as the medics. We had one medic go to one plane, one to the other, unfortunately the findings were they both were probably deceased on impact,” said Sonsteng.

The field is considered uncontrolled, meaning there is no air traffic control tower and pilots are encouraged but not required to use radios.

“Generally the pilots in an operation like this would be in contact with each other on a common radio frequency to let each other know where they were and what their plans were,” said Laura Brown, a FAA spokeswoman.

Winds at the time were estimated to be between 15 and 20 miles per hour. The FAA and NTSB are investigating if wind played a role, as well as if something mechanical may have gone wrong.