Amazon boss Jeff Bezos revealed in late 2013 during a segment on news program 60 Minutes that his company was actively developing an autonomous drone delivery system. A few days later, UPS said it was also looking into the matter.

In the more than three years that have elapsed, both companies (as well as a host of others) have made great strides in the market with Amazon conducting its inaugural Prime Air drone delivery a couple of months back. Now, we can add “Brown” to the list of couriers that have successfully pulled off an aerial drone delivery.

In partnership with Ohio-based battery-electric truck and drone developer Workhorse Group, UPS said it used a Workhorse HorseFly UAV delivery drone to make a delivery while a UPS truck driver continued down the road to make another delivery in person.

The drone in question docks on the roof of the truck and has a cage that hangs below. Through a hatch in the truck, the driver can load a package into the drone’s cargo hold and send it on its way. The drone, which features a 30-minute flight time and a top speed of 45 miles per hour, can carry a package weighing up to 10 pounds and recharges itself while docked atop the UPS truck.

As per current FAA rules, the drone had to maintain line-of-sight with a pilot and it flew a pre-programmed route for the sake of the test.

A bit concerning is the fact that, as TechCrunch highlights, a second, unofficial demonstration of the drone didn’t go very well. Some sort of interference, possibly from the broadcast reporters’ cameras, caused issues with the drone’s compass. The drone aborted its launch, the publication said, and tried to land on top of the UPS truck but fell to the side and was nearly crushed by the still-closing lid of the vehicle. Oops.