After operating in stealth mode for the last four years, San Francisco-based Xwing said in a news release last week it has carried out a number of passenger-carrying flights from take-off to landing remotely using a Cessna 208B Grand Caravan.

Xwing’s Auto-flight System retrofits existing aircraft into optionally piloted vehicles by integrating with on-board flight control systems that allow the aircraft to navigate, take off and land autonomously. This ensures a more cost-effective operation for logistic companies.

 The system is supervised by remote operators who work with air traffic controllers to ensure safety throughout the flight.

Instead of building autonomous helicopters and planes from the ground up, Xwing is focused on the software stack that will enable pilotless flight of existing aircraft. The company raised $10 million in new funding

Xwing has completed a large volume of testing on its Caravan with thousands of simulation runs, software system tests, and flight tests that include low and high-speed ground taxi tests, take-offs, navigation, detect-and-avoid tests, and landings.

The Cessna 208B Grand Caravan, a utility aircraft that has historically been used for cargo, flight training and humanitarian missions, will be the initial center-piece of its plan to operate commercial cargo flights. The plan is to have a regional focus and operate within a 500-mile range with flight paths over unpopulated areas.

Since July, Xwing has completed more than 70 hours of engine time for ground and flight tests, and more than 40 hours of automated flight time.

The Auto-flight System is designed to be aircraft agnostic, and it still is, Xwing said in a recent phone interview. “The Cessna 208B Grand Caravan is just the beginning.”

Xwing says it has obtained a Part 135 Air Carrier certificate and wants to begin commercial cargo flight operations in the coming months. Xwing expects to deploy its technology to market more quickly by operating its own fleet, but it’s open to future partnership and licensing opportunities with other operators to make the technology more widely available.

The company says its business model increases aircraft operator utilization by 3 times, equating to a 20 to 30 percent cost savings in for the $142.4B US air cargo transportation market.