Update: Zipline Flies Without Ground Observers Under ‘Holy Grail’ of Drone Approvals

Trick question—the FAA requires commercial drone operators to station humans on the ground, called visual observers (VOs), to keep an eye on every flight. So, the aircraft technically aren’t allowed to fly where no one sees them.

That is, unless you have a waiver, like the one drone delivery provider Zipline secured in September. On Friday, Zipline, which primarily delivers medical cargo such as blood, vaccines, and prescriptions in the U.S. and abroad, used that approval to complete what it says was the first beyond visual line of sight (BVLOS) drone flight in the U.S. without VOs.

Human observers were replaced by Zipline's detect and avoid (DAA) system, which is integrated onboard its drones. The company is a defendant in an ongoing patent infringement lawsuit disputing its use of the tech, filed in August 2022.

The drone delivery giant had already flown BVLOS under prior FAA exemptions. But last week was the first time it—or any other firm in the U.S.—has flown without VOs along the route. There is no video of the flight, since no one was there to see it.

“This is widely considered the holy grail of approvals for scaling drone delivery operations,” said Okeoma Moronu, head of global aviation regulatory affairs at Zipline. “We thank the FAA for their leadership and support throughout this process.”

BVLOS refers to flight beyond the view of the pilot or operator. But in the U.S., the FAA requires VOs to keep an eye on BVLOS drone flights. In other words, these flights are not truly beyond the visual line of sight, and they’re often limited to small service areas as a result. 

Removing the VOs, therefore, can greatly expand the scope of a drone delivery provider’s operations beyond where it’s able to station humans on the ground.

“This exemption from the FAA represents a monumental shift for logistics and equitable access in the U.S.,” Liam O’Connor, chief operating officer of Zipline, said in a blog post. “It builds the foundation for Zipline to scale to deliver food, medicine, consumer goods and other supplies to millions of Americans on demand, and to do so in an environmentally conscious way, resulting in 97 percent fewer emissions per delivery than a gas-powered vehicle.”

Zipline flew its Platform 1 (P1) drone without VOs in Salt Lake City within an hour of receiving the all-clear from the FAA. Ground-based personnel were replaced by onboard perception technology, including the company’s DAA system. DAA functions like a bat’s echolocation, detecting aircraft as far as 2 miles away using acoustics.

“This system has been tested by flying tens of thousands of real-world miles around the globe and through tens of thousands of test encounters with aircraft,” said O’Connor. “It has been designed to operate with the highest level of safety regardless of visual observers along flight routes.”

Zipline’s use of DAA tech is in dispute. In August 2022, technology innovator Scientific Applications and Research Associates (SARA) filed a lawsuit accusing the drone delivery provider of patent infringement.

SARA’s patent, entitled “Acoustic Airspace Collision Detection System,” describes a system that relies on sound to detect nearby aircraft or obstacles, similar to Zipline’s. It was awarded in 2009. The company’s complaint alleges Zipline breached a confidential non-disclosure agreement between the firms and relied on portions of SARA’s patented design in the development of its own DAA system. The case remains active, and Zipline has denied all claims.

“Our revolutionary Detection and Avoidance system uses proprietary technology that more than 100 Zipline engineers independently developed specifically for our aircrafts,” a Zipline spokesperson told FLYING. “This lawsuit entirely lacks merit and we will vigorously defend ourselves.”

A spokesperson for SARA gave its counterpoint statement, telling FLYING the company “will continue to vigorously defend our intellectual property in the legal proceedings now underway.”

Nonetheless, the FAA in September deemed Zipline’s onboard perception system, combined with a hefty helping of operational restrictions, to be just as safe as placing VOs along the company’s routes. Those limitations require Zipline to fly below 400 feet; maintain a list of aircraft components; submit a collision and avoidance plan for all operational locations; and steer its drones well clear of other aircraft.

The regulator’s approval allows Zipline to fly without VOs in Bentonville, Arkansas, and Salt Lake City, where the company is now delivering to customers without the requirement. It plans to expand the approach across its U.S. operations.

“Earlier this year, Zipline became the first company in U.S. history to receive approval from the FAA to leverage an onboard perception system to enable autonomous long-distance drone delivery flights, and [Friday], we made history doing just that,” said Moronu. “This means that Zipline can now go from serving a few thousand homes to serving hundreds of thousands of homes within the U.S.”

Calling it the holy grail may sound dramatic, but the removal of VOs should have a significant effect on Zipline’s operations. 

Its drones are capable of flying nearly twice as far as previous approvals permitted. And without the need for VOs, the door is open for the company to operate much longer routes in the U.S., similar to those it flies in Africa. The reduced reliance on human capital also figures to decrease operating costs.

Other companies should be excited about Zipline’s new permissions too.

In lieu of a permanent rule for BVLOS operations, the FAA awards temporary waivers to certain regulations. In September, the agency gave BVLOS permissions to four firms, including Zipline. 

Another recipient, UPS Flight Forward, was permitted to replace VOs on BVLOS routes with remote operations centers, which could be tens or even hundreds of miles away from its actual operations. Phoenix Air Unmanned was also authorized for BVLOS operations without VOs.

However, the permissions are not permanent. The FAA uses waivers to collect data on BVLOS flights, which it hopes will inform its proposed rule on BVLOS regulations, published in the Federal Register in May. The proposal is based on recommendations from the agency’s BVLOS Advisory Rulemaking Committee, a coalition of industry stakeholders tasked with building the framework for a final rule.

The waivers are rare—only a handful of drone operators have obtained them, and nearly all come with significant restrictions. But the FAA expects September’s round of approvals will open things up.

“Our goal is to work towards summary grants as we continue towards rulemaking,” said David Boulter, FAA associate administrator for aviation safety, at the Commercial UAV Expo in Las Vegas that month.

Summary grants are essentially streamlined authorizations for “copycat” companies with similar infrastructure, aircraft, and technology to those who have already been approved. 

The FAA intentionally picked applicants with four different use cases to simplify the waiver process for a wide spectrum of operators. A medical drone delivery provider, for example, could look to Zipline’s approval as a blueprint for the operational requirements needed to secure its own BVLOS permissions.

For now, though, only a handful of operators can routinely fly commercial BVLOS drone flights, and many of them are using waivers that are several years old. 

Out of the five companies that have been awarded FAA standard Part 135 air carrier certificates, Zipline and UPS Flight Forward now have the longest wait before their BVLOS permissions expire. Amazon Prime Air, Alphabet’s Wing, and Flytrex partner Causey Aviation Unmanned are the other three firms authorized for commercial operations under Part 135.

Those companies certainly have a leg up on the competition. But with the removal of VOs, Zipline may have the entire field beat. The company says it makes about 10,000 commercial deliveries per week, equating to about one every 70 seconds. Already, it’s completed more than 815,000 deliveries across seven countries, dwarfing all other competitors—Wing is the next closest with about 350,000 as of October.

“Zipline can now have the kind of positive impact in the U.S. that we’ve had in other countries where we can fly more than 140 miles round trip, beyond the visual line of sight of any observer, all day every day,” said O’Connor. “We have flown over 50 million commercial autonomous miles around the world, carrying everything from blood, pharmaceuticals, vaccines, educational materials, food, and convenience items to tens of millions of people.”

The next step for Zipline will be the introduction of its Platform 2 (P2) system, which it says will make 10-mile deliveries in as little as 10 minutes. P2 will introduce several new pieces of tech, including a delivery droid that will replace P1’s parachute delivery system; easily installable docking and charging stations; and what is essentially a drone drive-thru window.

P2 emphasizes automation, with the only human involvement coming from the employees loading orders and remote pilots overseeing each flight. The system is expected to debut next year, though the company plans to continue P1 operations in certain markets.

It’s unclear, however, whether Zipline’s VO permissions extend beyond P1 operations. The FAA identified the company’s Sparrow drone, or P1 Zip, which it uses to conduct P1 flights, as the approved model. The new system will rely on a slightly different model, the P2 Zip. Zipline did not immediately respond to FLYING's request for comment.

As the FAA relaxes VO requirements for other drone operators, Vance Hilderman, CEO of aviation consultancy AFuzion, told FLYING there will likely be new problems for the regulator to solve.

Specifically, urban air mobility (UAM) aircraft, such as electric vertical takeoff and landing (eVTOL) air taxis, will increasingly share the airspace below 500 feet with drones, creating the potential for intersections with drone delivery routes—and collisions. Hilderman suggested the adoption of publicly published UAM routes, which could ensure drones are not in the path of other low-flying aircraft.

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