Lilium's latest fundraising campaign has been launched as the public company seeks to preserve its listing on New York's Nasdaq market after being notified on April 13 that it was not compliant with the requirement to maintain its closing bid price above $1. A subsidiary of existing shareholder Tencent Holding is ready to contribute $100 million and also a further $75 million if other backers will match this amount.

The latest Revolution.Aero conference offered a reality check for the advanced air mobility sector, which has been referred to as the fourth aviation revolution. Industry leaders from manufacturers, leasing groups, technology innovators, infrastructure developers, the finance community, and independent market analysts mostly advocated for a long-game approach, though the first eVTOL air services are said to be barely 18 months away from launch.

For the past two years, Whisper Aero has been in stealth mode developing what it says will be the quietest and most efficient propulsion system on the market.” Upon closing a $32 million Series A funding round, the company finally broke its silence to reveal some details about its ultra-low-noise thrusters. We now know that Whisper’s proprietary propulsion system is some kind of next-generation electric ducted fan that can be scaled for applications ranging from aircraft to leaf blowers. However, Whisper isn’t ready to divulge exactly what makes its ducted fan quieter and more efficient than anything else on the market.

Joby Aviation is expanding its partnership with Toyota Motor Corporation, which previously invested nearly $400 million in the California-based eVTOL air taxi developer. Under a new agreement, the Japanese carmaker will manufacture key components of the aircraft’s powertrain and actuators before delivering them to Joby’s electronics manufacturing facility in San Carlos, California. Joby engineers will then finish assembling the components and send them to the company’s pilot production facility in Marina, California, for integration into the aircraft.

Both the aviation and automotive industries, as well as the transportation industry at large, are increasingly trending toward electric vehicles to reduce humanity’s dependence on fossil fuels and make transportation more sustainable. However, the lithium-ion batteries on which these industries depend may not be as sustainable as they may seem.

ZeroAvia will convert a Dash 8 Q400 aircraft—donated this week by one of its investors, Alaska Airlines—to use its hydrogen propulsion system. The company wants to be able to support commercial operations by converting regional airliners with between 40 and 80 seats by 2027 and plans to deliver smaller 19-seat aircraft from 2025.

This week, eVTOL aircraft developers Moya Aero and Jaunt Air Mobility secured new prospective customers. ZeroAvia expanded its alliance to put in place the infrastructure to support hydrogen-powered aircraft with the addition of France’s Absolut Hydrogen. And NASA is backing Embry-Riddle Aeronautical University to complete a study of projected noise levels from eVTOL vehicles.

Two years ago almost to the day, AIN published this FutureFlight explainer video in which we tried to understand the frenzied excitement among investors for start-ups that were then promising to get new eVTOL aircraft into commercial service in 2024. Independent expert Sergio Cecutta of SMG Consulting was our valued guide at the time and now he and others are trying to make sense of a very different financial environment for the advanced air mobility sector. With funds now harder to secure, and the difficulty of certifying new aircraft now all too apparent, it is instructive (and somewhat sobering) to reflect on the mood music being played back in the springtime of 2021.