The Future of Advanced Air Mobility

Joby Aviation, established in 2009, started developing a two-seat S2 eVTOL model but more recently seems to be focusing its efforts on the four-seat S4. Beyond this, there appear to be plans for a still larger S5 model.

However, in May 2020, the secretive company somewhat clarified its program plans by describing the S4 model as a "Generation 1" prototype. In a late September interview with Aviation Week, it further clarified that this version is referred to internally as the 1.0, with a larger, five-seat version for now designated as 2.0, or "Generation 2." Evidently, the 2.0, which has an increased maximum gross takeoff weight of 4,800 pounds and a new forward-swept V-tail, began flight testing at some point during 2019.

As of May 2020, the 1.0 aircraft had completed more than 200 flights (after an earlier subscale model had done more than 700 flights). Joby reported that at some point during 2019, it started flight testing a version that it now describes as its "passenger capable Generation 2" aircraft, which may or may not be the same design as the S5. The company has also referred to this model as a "production prototype."

On January 15, 2020, California-based Joby announced the completion of a Series C funding round that raised $590 million in new capital, including $394 million from Japanese automaker Toyota. Other investors included private Saudi Arabian business Abdul Latif Jameel through its investment division Jameel Investment Management Company.

Joby says that its first production eVTOL aircraft will be certified and ready to enter commercial service by the end of 2023. Having applied to begin FAA Part 23 type certification in 2018, it is reportedly one of four eVTOL developers currently working on this process with the U.S. agency. The company told Aviation Week that it is "somewhere between 70 and 80 percent complete" in defining the means of compliance for certification, covering both the airframe and the electric propulsion system.

In December 2019, Joby and ride-share group Uber announced a partnership through which Joby will operate the aircraft as part of the Uber Air air taxi network. This makes Joby the first of Uber's eight prospective manufacturing partners to announce firm plans to begin commercial operations with an eVTOL aircraft.

In the January announcement, Joby said that between 2014 and 2017 it (secretly) conducted "hundreds" of piloted flights with full-scale examples of the S4. Flight testing of a production prototype began in 2017 and that year the company also initiated the type certification process with the U.S. Federal Aviation Administration.

As of early 2020, Joby was completing the construction of a manufacturing and test facility at Marina, California. Toyota will provide advice on manufacturing and quality control.

Power for the all-electric aircraft family is based on the distributed electric propulsion system that Joby has developed as part of earlier work with NASA through its LEAPTech program. This consists of six five-bladed propellers powered by separate electric propulsion units, with four located on its wing and the other two on the tail.



first delivery

Joby Aviation has said that, having completed type certification, it will begin commercial operations with the S4 eVTOL aircraft by the end of 2023 in partnership with Uber.

type certification applied

On an unspecified date in 2017, Joby Aviation applied to begin type certification of its S4 eVTOL aircraft.

test flight

Between 2014 and 2017, Joby Aviation says it made "hundreds" of flights with full-scale examples of the S4 eVTOL aircraft. On an unspecified date in 2017, the company began flight testing a full-scale production prototype.

program launched

Joby Aviation was founded during 2009.


Our objective assessment of this program’s probable success.

FutureFlight assesses the probability of success for a new aircraft program by considering the following criteria:

  • Total investment funds available in proportion to the anticipated cost of getting an aircraft certified and in service
  • A company’s in-house capability (in terms of numbers of engineers, technical staff, and customer support teams)
  • The past experience of the company and its senior leadership in developing aircraft
  • The caliber and past experience of key program partners
  • Whether key aircraft systems have been selected and are available for use
  • Whether the preliminary design review has been completed
  • Whether the design for the full-scale prototype has been completed
  • Whether the type certification process has been formally initiated with an appropriate regulator
  • Whether the company has achieved a first flight with a full-scale prototype
  • The number of hours logged in a flight test program
  • Whether type certification has been achieved
  • The number of orders and commitment received for the aircraft
  • Whether the company has adequate facilities to begin series production of the aircraft
Our Methodology

The credibility of Joby Aviation's plans took a big leap forward on January 15, 2020, when it announced the completion of a Series C funding round that raised an additional $590 million. The main investor is Japanese auto giant Toyota, which sees this as a strategic move into aviation and will provide advice to the startup on manufacturing and quality control. Joby, which was formed back in 2009, has now raised a total of $720 million.

The announcement also marked, hopefully, the end of a deafening silence from Joby on its plans. It now says that it has been flight-testing since 2014 and filed a type certification application back in 2017. The company has publicly committed to being ready to begin commercial operations with its partner Uber in 2023. 

Joby would now appear to be one of the more credible entrants into the urban air mobility market and it has now spent just over 11 years advancing its plans. That said, the next 24 months will be critical in determining whether it can deliver on its ambitious program timeline.

Only during 2020 has Joby's management team begun to lift the veil of secrecy around its work, perhaps prompted by expectations from investors of greater transparency. The very limited public briefings provided do appear to confirm that Joby's engineering team is adequately resourced and experienced to be one of the first eVTOL pioneers to complete FAA certification. What remains unclear is how exactly it intends to transition to operating the aircraft since the company still appears intent on retaining control at the point of commercial service entry, rather than marketing the aircraft to experienced operators.

Joby eVTOL Models

Joby S4 Specifications

local vtol Lift + Cruise


  • Passenger Capacity
  • Range
    172 mi
  • Cruise Speed
    150 mph
  • Powerplant Type
  • Power Source
  • Endurance
  • Max Altitude
  • Takeoff Distance
  • Landing Distance
  • Empty Weight
    4,800 lb
  • Payload Weight


  • Length
    21 ft
  • Width
  • Height
  • Wingspan
    38 ft

The five-seat S4 prototype is electrically powered and uses Joby's LEAPTech distributed electric propulsion system developed as part of early programs with NASA. The S4 represents what Joby calls its "Generation 1" eVTOL aircraft. At some point during 2019, it started flight testing what it called its "Generation 2" aircraft, which the company has indicated is capable of carrying passengers. This appears to be closer to the final production aircraft than earlier iterations. No performance details and specifications have been released about this model.

The S4 prototype is an all-electric-powered aircraft featuring six sets of propellers—four mounted on the wings and two aft—with a cabin optimized for ride-sharing operations and easy passenger ingress and egress. Capable of reaching a speed of 200 mph, it will have a range of 150 miles on a single charge. It also will be 100 times quieter than conventional aircraft during takeoff and landing, and nearly silent in forward flight, Joby claims. Electrical power is stored in multiple Lithium-nickel-cobalt-manganese-oxide batteries.


Total Amount Invested: $394m

Key Personnel

JoeBen Bevirt is founder and CEO of Joby Aviation.
JoeBen Bevirt

Chief Executive Officer (CEO), Founder

Paul Sciarra
Paul Sciarra