Joby Aviation and Lilium have both marked new progress toward meeting key goals on their paths to type certification and commercialization, building on a string of positive momentum that has led investors to bid up shares of air-taxi companies in recent weeks.

Joby on July 6 announced it had submitted all of its certification plans to the FAA, part of the third stage of the five-step type certification process in which OEMs identify the tests and analyses they will conduct to prove compliance with aircraft-specific safety regulations spelled out in their second-stage Means of Compliance.

Joby’s submissions include about a dozen Area-Specific Certification Plans covering hardware and software aspects of every system aboard the five-seat S4 electric vertical-takeoff-and-landing (eVTOL) air taxi, including flight controls, energy storage and distribution, and propulsion systems, according to the company. Other covered areas include safety and cybersecurity.

Before the third stage of the process can conclude, however, the FAA still must sign off on all of Joby’s submitted certification plans. As of early May, the agency had approved 63% of the required submissions, according to the company’s first-quarter shareholder letter.

The progress from Joby comes after it in late June rolled out the first partially conforming prototype from its Marina, California-based pilot production line, which was granted special airworthiness certification by the FAA to perform company flight testing. Following those not-for-credit tests, the prototype will head to Edwards AFB, California, to be operated by Joby under its contract with the U.S. Air Force’s Agility Prime Program.

Adding to the good news, Joby announced in early July it had executed a $100 million equity sale to South Korean wireless carrier SK Telecom, building on Joby’s industry-leading balance sheet, which stood at $978 million at the end of March.

Lilium, meanwhile, announced on July 6 it had completed the fourth and final audit required to receive its Design Organization Approval (DOA) from the European Union Aviation Safety Agency (EASA). Receipt of the DOA is a requirement for European aircraft OEMs. It demonstrates they have the necessary organization, procedures, competencies and resources to design and certify aircraft safely.

With its final EASA audit completed, Lilium now enters the final DOA phase, in which it will follow up with the agency and work to close out all outstanding actions and administrative steps. The company said it expects to satisfy all requirements and receive its DOA certificate “later this year.”

The announcement also adds to recent positive developments from the German startup, which announced in late June the FAA had approved its application to begin negotiating the certification basis for its electric air taxi, the first step in the type certification process. Receipt of the G-1 from the FAA is a necessary step for Lilium to achieve concurrent validation in the U.S. of its EASA-issued type certification, a process spelled out under the Bilateral Aviation Safety Agreement between the EU and U.S.

Lilium also has seen its financial outlook improve in recent months after it announced in early May it had begun a new equity campaign for up to $250 million led by shareholder Tencent of China.

The positive news from Joby and Lilium, as well as from other publicly traded eVTOL companies like Archer Aviation, has sent their shares on a big rally this summer after declining for most of the early months of the year.

Shares in Joby this week briefly traded above their initial-public-offering price of $10.90 for the first time since September 2021, although the stock has pared gains in recent sessions. Lilium’s shares also reached a recent high of $1.90 on July 3, marking a sharp rebound since bottoming out at below 40 cents this spring amid concerns about the company’s financial runway.