Pilots report sharp increase in close calls with drones

SAN JOSE, Calif. (KGO) -- Pilots are reporting a sharp increase in close calls with at least 70 drones this month. Two of those incidents occurred near Mineta San Jose International Airport.

It's not the number of close calls that has people concerned, but also the altitude at which these drone encounters are happening. The incidents occurred over a no-fly zone of over 400 feet.

Pilots of two single engine planes reported close calls with drones in the vicinity of Mineta San Jose International Airport two Sundays in a row.

The pilot of a Diamond DA40 saw one at 2,600 feet about eight miles southeast of the airport on August 9. And on August 16, a pilot of a Cessna C172 reported seeing a drone passing just 500 feet beneath the plane at 3,800 feet, nearly seven miles southwest of Mineta San Jose International.

Pilots say a mid-air collision with a drone could be catastrophic. "If it were to hit in the elevator for instance, you would lose the pitch of the airplane. If you were to hit it on an aileron on the edge of the wing, you'd break a piece of the wing off, you couldn't control the roll of the airplane," Dick Deeds said.

The altitude at which these drones are flying is a big concern. Off-the-shelf drones have software code to prevent drones flying above 400 feet. "It could be they're custom building it and you could override the software if you custom build your own drone," Century Helicopters spokesperson Victor Duran said.

General aviation pilots are used to scanning the horizon for other small aircraft, but a drone is small and drone operators on the ground might not see a pending collision. "If you're on the ground, there could be a building or a tree or an obstruction and you don't see an aircraft coming in and that could pose a threat," The Flying 20 Flight Club President A.J. Borade said.

Mineta San Jose International and the FAA did not release a comment.

Borade says single-engine planes are the most vulnerable. "Especially for a smaller aircraft, you can definitely have much more significant damage. Some of these airplanes have only one engine. If that goes out, they're a falling rock," Borade said.