Killian Page/Reliable Robotics
California-based Reliable Robotics has flown a Cessna Caravan without a pilot on board for the first time. It's just one example of how autonomous vehicles are slowly making their way towards widespread use. Look through the gallery to see more.
HD Hyundai
HD Hyundai says its Prism Courage was the first large ship to cross the Pacific Ocean autonomously. In 2022, the 134,000-ton commercial tanker traveled from the Gulf of Mexico through the Panama Canal to South Korea's western Chungcheong Province in 33 days.
Ben Stansall/AFP via Getty Imagess
Fitted with six AI-powered cameras and 30 onboard sensors, the Mayflower 400, an autonomous research vessel designed to commemorate the 400th anniversary of the original Mayflower transatlantic voyage, sailed from Plymouth, UK, across the Atlantic Ocean to arrive in Massachusetts, US, in 2022.
Dubai RTA
The Dubai Roads and Transport Authority (RTA) has conducted trials of an autonomous Abra ferry, a wooden boat with a capacity of eight passengers, shown in this rendering. It's part of efforts to make a quarter of journeys in Dubai self-driving by 2030.
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All of Dubai's extensive metro (pictured here carrying passengers in November 2023) system is completely automated and driverless, and has been since 2009.
Jonathan Nackstrand/AFP via Getty Images
In 2022, Swedish firm Scania said it became the first in Europe to use an autonomous truck to deliver commercial goods.
Carlos Barria/Reuters/File
The age of driverless cars has been slow to materialize, but progress is being made, with autonomous taxis being trialed in a number of cities. A fleet of Zoox robotaxis, like the one pictured, is being road-tested in Las Vegas, Nevada.
Robert Perry/Getty Images
Operated by Scottish transport group Stagecoach, the UK's first full-sized driverless bus started carrying passengers in May 2023. With five buses in total, the small fleet will travel on designated roads at a maximum speed of 50 miles per hour (80 kilometers per hour), and despite the "driverless" name, two staff will be onboard to overlook operations.
CNN  — 

One of the world’s most widely used cargo planes completed an entire flight with no one on board for the first time.

Lasting approximately 12 minutes in total, the flight departed from Hollister Airport, in Northern California, and was operated by Reliable Robotics, which has been working since 2019 on a semi-automated flying system in which the aircraft is controlled remotely by a pilot.

The company recently announced that the 50-mile flight took place in November. The plane was a Cessna Caravan, a robust single-engine aircraft that is a popular choice for flight training, tourism, humanitarian missions and regional cargo.

“Cessna has made 3,000 Caravans — it’s the most popular cargo plane you’ve never heard of,” says Robert Rose, CEO of Reliable Robotics. “Pilots will tell you it’s the workhorse of the industry.

“But the challenge with this aircraft is that it flies at lower altitudes and more adverse weather conditions than many large aircraft do today. So operating it is much more dangerous, and automation is going to go a long way to improve the safety of these operations.”

Consultancy firm AviationValues told CNN there are currently 900 Caravans in active service, and FedEx — which has been using the type since 1985 — is the largest operator with about 200 of them. Reliable Robotics is now working with the Federal Aviation Administration to certify its technology for commercial operations, and expects that process to be complete in as little as two years.

Not a video game

The remote operator — a real pilot who must be certified to fly the aircraft exactly as if they were sitting in the cockpit — sends commands to the plane via encrypted satellite signals, but does not pilot the aircraft in real time nor gets any visual feed from the plane itself.

The interface they use is closer to those used by air traffic controllers than drone pilots. “This is not a video game,” says Rose. “There’s no joystick and you don’t have the ability to hand-fly the plane remotely. There’s no video feed that gives you real-time feedback. The way they control the aircraft is essentially a menu of options: you can think of it like a ‘choose your own adventure’ based on where the aircraft is, and there’s a set of buttons to allow the pilot to redirect the plane somewhere else.”

Each command sent to the plane includes all instructions required to land, so the aircraft always knows what to do even if communications are lost. “You could say that the aircraft is autonomous,” Rose explains. “If you tell it to do nothing else, or if you lose communications with it, it’s going to do the last thing you told it to do, which is the definition of autonomy. It has no direct human control.”

01:52 - Source: CNN
Cargo plane flew with no pilot on board. Hear what aviation expert thinks

Compared to a traditional autopilot, the Reliable Robotics system is able to perform all phases of a flight, including moving out of the gate and towards the runway, as well as taking off and landing. But as far as other aircraft or air traffic controllers are concerned, this is just like any other plane, Rose says, because the remote operator will respond to radio calls and handle voice communications in such a way that it’s impossible to tell they’re not aboard.

What if something goes wrong? According to Rose, there’s at least one advantage in handling emergencies remotely: if a pilot loses control of the plane, they can immediately inform air traffic control of its position and last command. “In many ways this is better than the way aircraft operate today, because if you’re flying around in the sky and you lose radio communications, or something goes wrong with the plane, you have to do something and air traffic control has no idea what you’re going to do. So they have to clear the airspace all around you because nobody knows what your intentions are.”

Larger planes

Once the system becomes commercially available, other security measures will come into effect, including a smart card that will be required to operate any aircraft. In addition, pilots will work from a control center where other people will be watching over them.

For now, Reliable Robotics is looking to certify the system for the Caravan, but is already testing it on a larger aircraft with the US Air Force — the KC-135 Stratotanker, a military refueling plane based on the old Boeing 707 — and hopes to start testing on jet cargo aircraft within five to 10 years.

According to Rose, remotely controlled regional cargo planes would have positive effects on both safety and the ongoing pilot shortage. “The pilot shortage is putting pressure on smaller aircraft operations, because the larger planes are sucking up all the pilots, and it’s becoming much more difficult to sustain operations with smaller aircraft fleets.

“We see remote piloting as a way to solve that problem in the near future.” He adds that airlines will be able to streamline their operations because layovers will no longer be required, as pilots will be able to work from a single location.

Killian Page/Reliable Robotics
The crew preparing the Cessna Caravan for the unmanned flight.

As for safety, Rose says that the system will prevent common types of accidents that are linked to human error, such as “unintentional collisions with terrain” and loss of control in flight, which account for the majority of fatal crashes. Rose explains that the Reliable Robotics system has been designed to prevent them, for example by cross-checking against a terrain and obstacle database in case the plane is erroneously programmed to fly into something.

“Significant milestone”

The history of pilotless aircraft goes back to the early years of aviation, with the first examples of unmanned planes developed in the US and Britain during World War I. Most unmanned aerial vehicles today are categorized as drones, performing a range of functions from military action to search and rescue and photography.

Merlin Labs and XWing, both in the US, and Volant in the UK, are among the companies developing similar systems to Reliable Robotics, with a similar attention to the cargo sector.

In recent years, the concept of pilotless air taxis has also gained interest, with a first historic flight performed by German company Volocopter in Dubai in 2017; the Emirate is now planning to inaugurate its first “vertiport” for flying taxis within three years, albeit using vehicles manned by human pilots. In China, urban air mobility company EHang was the first to obtain, in October, full certification from the local authorities to fly a pilotless passenger-carrying UAV — the result of over 40,000 test flights.

Foster + Partners
Architects Foster + Partners has created a concept for a vertiport for vertical take-off and landing vehicles in Dubai, shown in this rendering.
XPENG AEROHT
Dubai has long planned for a flying taxi service. The XPeng X2 electric flying car completed its first public test flight in Dubai at the Gitex technology expo in October 2022.
GITEX 2022
Chinese company XPeng Aeroht hopes to have a flying vehicle available for public use in small regulated urban areas within just five years.
KARIM SAHIB/AFP/AFP via Getty Images
The XPeng X2 is just one of dozens of flying cars currently in development. SkyDrive's single passenger flying car, designed to be a zero-emission flying craft, was also on display at Gitex 2022.
JOE KLAMAR/AFP/AFP via Getty Images
Another air taxi in development is this vehicle from Chinese company Ehang. After several successful public test flights, it's hoped the Ehang 216 will be ready by 2025, when the Chinese government plans to have flying taxis in the air.
ALEXANDER NEMENOV/AFP/AFP via Getty Images
Hoversurf's Drone Taxi prototype took its first test flight in 2021, and the company hopes to have it in city skies by 2025. Hoversurf is also working on plans for a Drone Ambulance.
ANTHONY WALLACE/AFP/AFP via Getty Images
The German Volocopter 2X takes a different approach to the flying car challenge. Technically a multirotor electric helicopter, the vehicle is intended to act as an aerial taxi in built-up urban areas.
LIONEL BONAVENTURE/AFP/AFP via Getty Images
The CityAirbus NextGen prototype is an all-electric vertical take-off and landing (eVTOL) vehicle. What sets it apart from many other vehicles for urban flight is that it has room for four passengers rather than one or two.
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The Lilium Evtol Jet is designed to be a hovering minibus. It takes off vertically but cruises through the air on wings and uses electric jet propulsion.
Mathieu Lewis-Rolland/Getty Images North America/Getty Images
Israeli-founded company Eviation Aircraft has developed and successfully flown Alice, the world's first electric passenger aircraft intended for commuter travel.

According to Jack W. Langelaan, a professor of Aerospace Engineering at Penn State University, who’s not involved with Reliable Robotics, the company has achieved a significant milestone by completing a flight from hangar to hangar without an on-board pilot.

“There are lots of hard things in robotic aircraft,” he told CNN. “Two of them are dealing with the unexpected and fitting into the existing air traffic control system. The unexpected includes things like mechanical and sensor failures.

“We can’t anticipate everything and we need to prove that the robotic ‘pilot’ is at least as competent as a good human pilot. Fitting into the air traffic control system is also tricky: at the moment it’s managed by humans talking to each other by radio, so Reliable used a remote pilot to manage this aspect of the flight. And of course, the human remote pilot was also ready to step in to deal with the unexpected.”

Gary Crichlow, head of commercial analysts at consultancy firm AviationValues, agrees that the technology to enable uncrewed operations is impressive. “That being said, the jump between crewed operations and uncrewed operations on a global scale is an extremely large one,” he cautioned. “It’s not just about the technology, it’s also about the economics and politics of replacing a highly skilled group of people with that technology. If anything, I’d expect those barriers to be even more difficult to overcome than the technological hurdles.”