The Future of Advanced Air Mobility

Baaz Banks On Folding Wings and Ducted Propellers to Overtake eVTOL Rivals

German start-up Baaz is working on an all-electric eVTOL aircraft that it says will significantly overtake the range provided by rival designs with the ability to fly up to 350 km (219 miles). The distinctive design for the B5 model features folding wings to give it more flexibility operating in urban areas, as well as a novel propulsion system built around five ducted propellers.

The company, which was founded in September 2019 by Hossein Malek Zadeh, a former senior engineer with automotive technology group Siemens-Valeo, is aiming to have a prototype ready to fly within two years, as well as an iron bird ground test unit. It anticipates completing type certification, which will initially be under EASA’s Special Condition VTOL CS-23 rules, by the end of 2025.

According to Baaz, the 13.5-meter (44 foot) wingspan plays a big part in delivering what it says will be market-leading range. The structure will fold in from the ends to reduce the span to 7.8 meters. The aircraft will be able to takeoff and landing in conventional STOL mode as required.

Four of the ducted propellers are positioned high and horizontally in each corner of the fuselage, i.e. two in the front and two at the rear. The rear propellers can swivel up to provide extra push for cruise flight, and a fifth propeller is encased within the rear fuselage. Baaz claims the ducted propellers will have a lower noise profile than propulsion systems on similar aircraft, with the configuration displacing the noise tonality.

According to chief marketing officer Jacques Gatard, the fifth ducted propeller is a significant safety feature in that it can compensate for the loss of power and balance if one of the external ducted propellers fails. It also spreads the weight more effectively across the airframe.

At face value, the B5’s folding wings and tilting rear propellers might seem to be quite challenging from an engineering and certification point of view. Leonardo and Bell Boeing faced significant challenges in developing their respective AW609 and MV-22 tiltrotor designs, but the Baaz engineering team claims that with both of these aircraft much larger sections of the wings and engines rotated and that it's moving parts have a much lower mass. It also maintains that the elevated position of the B5’s propellers does not interrupt the airflow over the wing.

The B5’s cabin features three seats in the rear section behind two seats in the front for the pilot and another passenger. Since the rear seats can be removed, this configuration allows space for a stretcher to be fitted for medical support operations or cargo loaded for logistics flights, such as resupplying ships or offshore installations.

Baaz intends to outsource manufacturing of many of the B5’s individual components and systems, with its role focused on the overall design and technology integration. Final assembly of the aircraft will be conducted at the company’s headquarters at Erlangen in southern Germany. The town is a major center for electrical engineering group Siemens, which has extensive expertise in electrification and automation.

Currently, the company is entirely funded by Malek Zadeh. He previously ran the Siemens-Valeo group’s electric powertrain operation, working on programs for carmakers Daimler, AMG and VW and establishing a new test center.

CFO Arne Lehmkuhl said that Baaz, which is the Urdu word for a falcon, will seek further direct investment and loans to support the program. “We don’t expect to make the same mistakes as other start-ups, but avoiding the costly trial and error phase,” he told FutureFlight.

The company has already filed patent applications covering the propulsion system and folding wings. It also intends to patent its own battery cooling system.