Bivect Air Nymbus (concept design)

(Image credit: Bivect Air)

Nymbus (concept design)
Bivect Air, Inc.
Sainte-Marie-Saint-Raphaël, New Brunswick, Canada
www.gary-gress.pixels.com

Gary Robert Gress, a Canadian mechanical engineer and lifelong aviation innovator is the sole principal of Bivect Air. Gress has has developed multiple two propeller passenger electric vertical takeoff and landing (eVTOL) for advanced air mobility. His approach to aircraft design blends decades of aerospace engineering experience with a deep curiosity for vertical takeoff and landing (VTOL) history—from early helicopter concepts to modern gyroscopic control systems. In addition, Team Bivect Air participated in the GoAERO competition in the United States (2024-2027) but was unfortunately not a Stage 1 or Stage 2 winner. Gress plans to enter the GoAERO Stage 3 contest.

Some background information about Gress
After retiring around 2012, he returned to school to complete his M.Sc. and Ph.D. in Mechanical Engineering at the University of Calgary, with the goal of fully understanding the control of hovering aircraft. His design teacher, who was not in the aerospace industry, taught Gary an invaluable lesson that has spurred him to continue even when he confronts seemingly insurmountable barriers. He once said to the class: "It takes a lot of work to make something simple," he remembers. "I think that is so true and it applies everywhere.," Gress said.

Transitioning eVTOL Aircraft with Augmentative Cross-Modal Elements White Paper
Gress presented "Transitioning eVTOL Aircraft with Augmentative Cross-Modal Elements" at Forum 80, sponsored by the Vertical Flight Society, May 7–9, 2024, Montréal, Québec, Canada. His proposition boiled down, is that two propellers are the right amount of propellers for an eVTOL aircraft with respect to weight and drag considerations. That is, each addition propeller increases weight and drag for the aircraft. In addition, Gress states that two propellers are sufficient for hovering due to what is called active tilting. Active tilting involves the use of the propellers’ gyroscopic, momentum-wheel and drag-torque moments which keeps the aircraft stable during hovering. Three of several aircraft that he cites in the paper are his own prototype aircraft, the AW609 tilt-rotor and the Agusta-Westland Project Zero.

Numbus scalable passenger eVTOL tilt-propeller (concept design)
The Numbus is a scalable one passenger eVTOL tilt-propeller used for short local personal trips, business trips or for recreational flying. The aircraft has a canopy over the cockpit with room for the passenger's luggage. A 3-D subscale model of the concept design aircraft is above. Since this is a scalable concept design aircraft, the specifications would change for a two passenger aircraft.

The cruise speed for the aircraft is approximately 161 km/h (100 mph). The flight time at minimum power is estimated at 70 minutes. The flight time at maximum power is expected to be 29 minutes. The aircraft has two counter-rotating propellers, two electric motors and is powered by lithium-ion batter packs. If a prototype aircraft would be made, the aircraft would most likely look much different than the model and would include wings and have smaller propeller nacelles. The aircraft has a rear T-tail. The fuselage is made from carbon fiber composite to give the aircraft a high strength to low weight ratio. The aircraft has fixed skid landing gear.

Specifications:

• Aircraft type: Scalable passenger eVTOL multicopter (concept design)
• Piloting: 1 pilot with luggage
• Cruise speed: 161 km/h (100 mph)
• Flight time (minimum power): 70 minutes
• Flight time (maximum power): 29 minutes
• Propellers: 2 counter-rotating propellers
• Electric motors: 2 electric motors, 60 kW rate each
• Power source: Li-Ion batteries
• Fuselage: Carbon fiber composite
• Window: Canopy over the cockpit
• Tail: T tail
• Landing gear: Fixed skid landing gear
• Safety features: Distributed Electric Propulsion (DEP) uses multiple propellers or electric ducted fans, each powered by electric motors, to increase safety through redundancy. If one or more components fail, the remaining ones can still ensure a safe landing. There are also redundancies of critical components in the sub-systems of the aircraft providing safety through redundancy. Having multiple redundant systems on any aircraft decreases having any single point of failure. Has shrouded propellers for additional safety.

Related Aircraft:

• Bivect Air Air Rider (concept design)
• Bivect Air Ariel (concept design)
• Bivect Air Odyssey (concept design)
• Bivect Air Rogue (concept design)
• Bivect Air Tandem-X (concept design)
• Bivect Air Twister (concept design)

Company Insights:

• Bizapedia

Resources:

• Gary Robert Gres website
• Gary Robert Gress Facebook
• Gary Robert Gress YouTube
• Gary Robert Gress LinkedIn