Can Toyota Teach Aviation How to Build at Scale?

Joby and Toyota’s manufacturing alliance points to one of eVTOL’s biggest challenges: building aircraft at a scale traditional aviation has rarely needed.

For years, the biggest questions surrounding eVTOL have focused on the technology. Could batteries provide enough range? Could distributed electric propulsion deliver the reliability aviation demands? Could an electric aircraft transition safely from vertical to forward flight while carrying a useful payload? After years of development and flight testing, the leading manufacturers have answered many of those questions. Their aircraft fly. The challenge now is turning those aircraft into products that can be manufactured consistently and in meaningful numbers.

On June 30, Joby Aviation and Toyota Motor Corporation announced the initial phase of a strategic manufacturing alliance intended to prepare Joby’s electric air taxi for commercial-scale production. The partnership brings together two companies with very different backgrounds. Joby has spent more than a decade developing and certifying a new category of electric aircraft. Toyota has spent generations refining one of the world’s most influential manufacturing systems. If eVTOL is going to become a meaningful form of transportation, that manufacturing expertise may prove just as important as the technology that gets the aircraft into the air.

Modern aviation manufacturing is extraordinarily sophisticated, but its volumes are tiny compared with the automotive industry. Even the most successful commercial aircraft programs produce numbers that would barely register at a major automobile plant. There are good reasons for that. Aircraft are expensive, complicated and tightly regulated. Components must be traceable, manufacturing processes carefully controlled and changes thoroughly documented. A defect in an automobile can create an expensive warranty problem. In aviation, a manufacturing defect can become a safety-of-flight issue.

That approach has helped make commercial aviation remarkably safe, but eVTOL presents manufacturers with a different production problem. Advanced air mobility depends on having far more aircraft in operation than most traditional aviation business models require. A useful urban or regional network could eventually need hundreds or thousands of aircraft flying repeatedly throughout the day. Producing aircraft in those numbers starts pushing aviation into territory where the automotive industry has considerably more experience.

Toyota is an especially interesting partner because its influence extends far beyond automobile manufacturing. The Toyota Production System helped establish practices such as just-in-time production, standardized work, continuous improvement and designing production processes so that problems are identified rather than buried farther down the line. Toyota and Joby have already spent years working together, with Toyota engineers supporting Joby’s manufacturing efforts and the company supplying key powertrain and actuation components. The new alliance formalizes and expands that relationship as Joby prepares for commercial production.

There are limits to the automotive comparison. A certified aircraft cannot simply be treated like a Corolla with propellers. Automakers routinely make running changes to components, suppliers and manufacturing processes as they improve a vehicle or reduce costs. Aviation requires much tighter configuration control. The provenance of components matters, manufacturing processes can become part of the certified product, and changes may require extensive documentation or regulatory approval. Regulators need confidence that an aircraft coming off the line months or years after certification meets the same standards as the aircraft originally evaluated.

This is where Toyota’s involvement becomes particularly relevant. Automotive manufacturing is built around achieving consistency at enormous scale, while aviation manufacturing is built around achieving consistency under extraordinary scrutiny. eVTOL manufacturers will need elements of both. They need the efficiency and repeatability required to increase production without abandoning the traceability and quality control required of certified aircraft. Toyota has spent decades studying production variation, process control and quality at volumes the aviation industry rarely encounters.

Manufacturing also can’t be separated neatly from aircraft design. A component that’s difficult to produce consistently becomes a production problem. Production variation becomes a quality problem, and in aviation, quality problems can quickly become certification problems. For eVTOL manufacturers, these relationships are especially important because many of the technologies involved are relatively new to high-volume certified aviation. Electric motors, battery packs, high-voltage systems, lightweight composites, distributed propulsion and sophisticated flight-control systems all have to be manufactured, installed and tested with extraordinary consistency.

For much of the past decade, competition within eVTOL has been easy to see. Manufacturers have proposed different numbers of rotors, wing configurations, approaches to transition flight, ranges, speeds and passenger capacities. As the leading programs move closer to certification, some of the most important competition is moving inside factories and supply chains. Production rates, cost control, supplier reliability, quality assurance, fleet support and access to capital will increasingly determine which companies can turn successful aircraft programs into sustainable businesses.

That makes the Joby-Toyota relationship significant beyond either company. It reflects a broader shift in eVTOL from proving that the technology works to figuring out how an industry can be built around it. Aviation history is full of technically successful aircraft that never became commercially significant. A viable transportation system requires far more than a machine capable of flight. The aircraft has to be produced economically, certified, maintained and supported throughout its operating life.

Joby has already demonstrated that its aircraft can fly. Toyota’s contribution addresses the considerably less glamorous work that comes next: making sure the same aircraft can be built again and again without sacrificing quality as production increases.

If eVTOL eventually becomes part of everyday transportation, the milestone that matters most may not be the first aircraft carrying passengers over a city. It may be the thousandth aircraft rolling off the production line.

Making number 1,000 as well as number one is a problem Toyota knows something about.