• +1-703-684-6777
  • info@evtol.news

NASA Side-by-Side (concept design)

NASA Side-bySide passenger eVTOL concept design helicopter (Image credit: NASA)


Side-by-Side (concept design)
Washington, D.C., USA

Established in 1958, the National Aeronautics and Space Administration (NASA) is an independent agency of the U.S. federal government responsible for the civil space program, aeronautics research and space research. NASA is headquartered in Washington, D.C. and has 10 major field centers. NASA has made space ships, explored space, the moon, launched satellites, gathered data about Earth from space, made the Skylab Space Station, explored Mars, studied our solar system using space probes and more. (Image credit: NASA)

NASA started researching distributed electric propulsion (DEP) electric vertical takeoff and landing (eVTOL) and hybrid-electric VTOL aircraft in 2009. DEP was introduced to the world in November 2009 when Mark Moore, while still at NASA, unveiled the Puffin, a personal an all-battery eVTOL concept design aircraft. For the first time, the world caught a glimpse at how electric propulsion might transform everyday flight. In 2010, according to one website, the first eVTOL aircraft flown was NASA's Puffin subscale eVTOL tailsitting aircraft.

In 2014, NASA built both eVTOL and fixed-wing DEP technology demonstrator aircraft. Some of the key design features for NASA's advanced air mobility (AAM) common reference vehicles is to increase safety exponentially, reduce the complexity of the aircraft, decrease the cost of manufacturing, minimize maintenance costs, lower the final ticket cost to the consumer, lessen or have no carbon footprint for the aircraft and decrease the noise level for the general public.

NASA has continued making passenger eVTOL concept designs, technology demonstrators and research eVTOL aircraft for any company that wants to take advantage of NASA's research. In addition, NASA is now making eVTOL and hybrid-electric eVTOL aircraft to explore planets and their moons, in our solar system. As of 2024, NASA's space probes have not traveled to any other solar systems in the Milky Way galaxy, yet.

Mark Moore, Co-Founder and CEO of Whisper Aero (formerly a Principal Investigator and Chief Technologist for On-Demand Mobility, NASA and Engineering Director of Aviation, Uber Elevate) at the Vertical Flight Society's 7th Annual Electric VTOL Symposium, Jan. 21-23, 2020 in San Jose, California, USA, stated concerning advanced air mobility (AAM), "There has not been this pace in aeronautics since the Wright Brothers."

NASA Side-by-Side passenger eVTOL concept design helicopter
The NASA Side-by-Side is a six person eVTOL concept design transverse-rotor helicopter that can accept all-batteries as a power source or use a hybrid-electric power source. A transverse-rotor helicopter is where there are two main rotorblades that are mounted side by side. NASA calls this concept design aircraft an Urban Air Mobility (UAM) reference vehicle, also known as a common reference model. The aircraft is either piloted or uses autonomous piloting. The aircraft has a typical helicopter windshield and windows.

The helicopter has two transverse or side-by-side rotorblades and they are intermeshing counter-rotating rotorblades. The rotorblades turn in opposite directions which cancel out each other's torque and therefore, there is no need for a tail rotor. The advantage of two main rotorblades is they can be shorter than a helicopter with one main rotorblade. This helicopter design can carry heavier payloads than a helicopter with one main rotorblade. In addition, all the power can be used for lift since there is no tail rotor. The rotorblades are powered by electric motors and the power source can be all-batteries or use turbine engine to create the electricity to power the entire helicopter.

NASA recommends to use Airbus Helicopters' Blue Edge rotorblades. These swept-back tip Airbus Helicopters' proprietary rotorblades reduce reduce rotorblade noise, reduce vibration, reduce fuel consumption and improve the aerodynamic efficiency of the rotorblades. The tail of the helicopter has two downward angled horizontal stabilizers. The two rotorblades will travel in opposite directions cancelling any torque that a helicotper with one main rotorblade would have. Therefore, no tail rotor is needed for this helicopter to fly correctly.

While the cruise speed of the rotorcraft is unknown, the estimated range of helicopter is 86 m (138 km). NASA recommends to have enough reserve cruise power for 20 minutes. The maximum payload weight is intended to be 1,200 lb (544 kg). The fuselage is made from carbon fiber composite for a high strength and low weight ratio. The helicopter has one inverted V tail and has fixed tricycle wheeled landing gear.

NASA advanced air mobility (AAM) aircraft research areas:

  • Aircraft Design
  • Noise and Annoyance
  • Operational Effectiveness
  • Performance
  • Propulsion Efficiency
  • Rotor-Rotor Interactions
  • Rotor-Wing Interactions
  • Safety and Airworthiness
  • Structure and Aeroelasticity

NASA's advanced air mobility (AAM) facilities and capabilities include:

  • Air Traffic Operations Lab
  • Airspace Operations Lab
  • Ames UAM Lab
  • CERTAIN Range
  • Cockpit Motion Facility
  • Cognitive Engineering Lab
  • Computational Fluid Dynamics
  • Developmental UAM Simulator - Flyer
  • Dryden Aeronautical Test Range
  • Exterior Effects Room
  • Flight Loads Lab
  • Future Flight Central
  • Icing Research
  • Landing and Impact Research Facility
  • Low Speed Aeroacoustic Wind Tunnel
  • Mobile Acoustics Facility
  • Mobile Operations Facility
  • Research Flight Deck
  • Testbed Virtual Infrastructure
  • UAS Flight Test Control Room
  • Vertical Motion Simulator
  • X-57 Maxwell
  • 12' Tunnel-Low-Cost Exploratory Facility
  • 14 by 22 Foot Subsonic Tunnel

In February 2023, NASA published an article title, "NASA is Creating an Advanced Air Mobility Playbook." NASA is working with academia, government agencies, industry, cities and tribal nations to make advanced air mobility (AAM) a reality. NASA's areas of support include accessibility, automation, cargo delivery, emergency response, future airspace, healthcare, infrastructure, noise, ride quality, safety, travel time, vertiports and more.

NASA Side-by-Side Urban Air Mobility (UAM) Reference Vehicle helicopter orthographic view illustrations (Image credit: NASA)

NASA Side-by-Side Urban Air Mobility (UAM) Reference Vehicle helicopter orthographic view illustrations (Image credit: NASA)


  • Aircraft type: Passenger eVTOL concept design helicopter
  • Piloting: Piloted or autonomous
  • Capacity: 6 total people
  • Cruise speed: Unknown
  • Range: 86 m (138 km)
  • Reserve cruise power: 20 minutes
  • Maximum payload weight, estimated: 1,200 lb (544 kg)
  • Rotorblades: 2 rotorblades that are side-by-side
  • Electric motors: 2 or more electric motors
  • Power source: All batteries or a hybrid-electric power source
  • Fuselage: Carbon fiber composite
  • Windows: Conventional helicopter windows
  • Tail: 1 inverted V tail
  • Landing gear: Fixed tricycle wheeled landing gear
  • Safety features: Distributed Electric Propulsion (DEP) means having multiple propellers (or electric ducted fans) and multiple electric motors on an aircraft so if one or more propellers (or electric ducted fans) or some electric motors fail, the other working propellers (or electric ducted fans) and electric motors can safely land the aircraft. DEP provides safety through redundancy for passengers or cargo. 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.

Company Insights: