The Vertical Flight Society (VFS) addressed the recent shakeups in the eVTOL arena on Monday afternoon at Verticon. Several high-profile players in the nascent market are either being sold at fire sale prices or being forced to throw in the towel altogether.

According to Mike Hirshberg, the group’s director of strategy and former executive director, “The last several months has resulted in several companies now in insolvency.” He specifically noted Volocopter’s breaking announcement that a Chinese company has agreed to buy it for €10 million—an amount he described as essentially nothing—as it ran out of funding needed to cross the certification finish line after 15 years of development.

“There is a huge gap between designing aircraft, building aircraft, flying aircraft, and then getting to production.” Hirshberg added that there are still several potential OEM pushing for certification but cautioned, “Just because you have a good idea doesn’t necessarily mean you are going to be successful in the business.”

He explained what he describes as the Hirshberg Principle: “You need about a billion dollars, 10 years, and 1,000 engineers to field a new aircraft.” For eVTOLs, he said to add 50 percent to those totals. “New technology takes a long, long time and a lot of money.”

VFS maintains a registry of the world’s eVTOL aircraft designs, and as of this week it has listed nearly 1,100, which it describes as ranging from the silly to the serious.

Among them, it breaks down the designs—from more than 400 companies— in vectored thrust (387), lift and cruise (200), wingless multi-rotors (321), hoverbikes/flying devices (111), and eHelos and gyros (76). Of those, Hirshberg predicts maybe five will be certified over the next half-decade.