As AFWERX Agility Prime celebrates two years, partner Joby Aviation announces acoustic data from NASA testing

Published May 17, 2022
By Katie Milligan
AFWERX

WRIGHT-PATTERSON AIR FORCE BASE, Ohio (AFRL) – AFWERX Agility Prime partner Joby Aviation, a California-based company developing an all-electric vertical take-off and landing (eVTOL) aircraft, recently completed developmental testing with NASA to help understand Joby’s vehicle’s performance characteristics and acoustics profiles during normal operations of take-off, landing, and overflight.

This announcement coincides with the two-year anniversary of the Agility Prime program, which launched April 27, 2020. In the past two years, Agility Prime has awarded over 250 contracts for research and development (including Joby’s current SBIR Phase III) along with four airworthiness certifications. The program has flown over 250 flight tests among its partners.

Joby’s eVTOL is a piloted, four-passenger aircraft that has a maximum range of over 150 miles powered fully by electricity, with a maximum speed of over 200 miles per hour and zero operating emissions. (Courtesy photo/Joby Aviation)

Joby Releases Data Following NASA Testing

Since Joby intends their vehicle to be used as an air taxi for commercial use in urban areas, its acoustic signature is key for public acceptance. Critics of eVTOL technology argue that a vertical takeoff method of transportation that can operate in an urban environment already exists: the helicopter. However, helicopters are expensive in fuel and maintenance and have been the subject of noise complaints.

In September 2021, Joby became the first eVTOL company to fly in NASA’s Advanced Air Mobility (AAM) National Campaign, focusing on aircraft operations and acoustic measurements for two weeks of flight testing. NASA engineers deployed their Mobile Acoustics Facility and over 50 pressure ground-plate microphones arranged in a grid to measure Joby’s sound emissions from all directions.

On May 10, Joby released a few initial results from that study: the company’s full-scale aircraft measured the equivalent of 45.2 A-weighted decibels (dBA) from a distance of 1,640 feet (500 meters) at 100 knots airspeed, a sound level which Joby is confident will barely be perceptible against the ambient environment of cities.

NASA engineers also measured the aircraft’s acoustic profile during take-off and landing operations representative of planned operations to be below 65 dBA at a distance of 330 feet (100 meters) from the flight path.

NASA also released more information about how these measurements were collected and analyzed. Both Joby and NASA will release further details on procedures and measurements in technical papers to be presented at industry conferences this summer.

This testing demonstrates the potential of distributed electric propulsion aircraft – when designed with acoustics in mind – to achieve an acoustic footprint that is orders of magnitude smaller than most rotorcraft aircraft in service today. With six five-blade propellers and high-torque motors, the Joby aircraft is able to achieve the lift necessary for flight with low rotor blade tip speeds, reduced even further in cruise by transitioning to wing-borne flight.

Joby’s full-scale pre-production prototype eVTOL, which features six electric motors powering propellers placed around the model. (Courtesy photo/Joby Aviation)

Joby’s history of collaboration with NASA began in 2012, when the entities worked together on various electric flight initiatives such as the Leading Edge Asynchronous Propeller Technology (LEAPTech) project and later on with the design of NASA’s X-57 Maxwell’s motors and cruise motor controllers.
Additionally, Agility Prime and NASA maintain a strong partnership, sharing data between their organizations in order to encourage progress in the AAM sector.

Joby’s Mission

Joby’s goal is to launch an aerial ridesharing service in congested cities around the world through partnering with rideshare services like Uber and constructing landing infrastructures near where people live, work, and want to go. After over ten years of development, Joby is currently conducting flight testing on what the company calls its full-scale pre-production prototype eVTOL, with six electric motors powering propellers placed around the airframe. It is a piloted, four-passenger aircraft that has a maximum range of over 150 miles powered fully by electricity, with a maximum speed of 200 miles per hour, zero operating emissions, and the ability to perform vertical take-off and landing.

Additionally, in December 2020, Joby completed an initial airworthiness assessment and received approval from the Air Force to support and operate their prototype test aircraft during U.S. Government-sponsored flight testing, becoming the first eVTOL company to do so. A year later, in December 2021, Joby received the same approval on their second prototype.

In the past year, Joby reached several milestones on their road to commercial operations. The company’s initial pre-production prototype made its first flight in conjunction with Agility Prime on March 26, 2021. A few months later, on July 14, 2021, the team proved the aircraft’s range with a record 154.6-mile flight. Then, in February 2022, Joby’s eVTOL achieved a new speed milestone, flying the aircraft in excess of 205 knots (235 miles per hour) and more than 11,000 feet above mean sea level – both believed to be records for eVTOL aircraft to date.

As part of the speed and altitude expansion campaign, Joby tested its aircraft’s performance at speeds significantly faster than its intended maximum and subsequently experienced a component failure during remotely-piloted testing over uninhabited land. Following a pause on flight testing introduced by Joby’s internal safety review board, the company has since returned to flight testing with its second pre-production prototype aircraft and continues to work with the FAA and the National Transportation Safety Board to investigate the accident.

In parallel with these flight testing accomplishments, Joby is also working with the Federal Aviation Administration (FAA) to certify its aircraft. Joby entered the implementation phase of the certification process for the first time in February and soon after announced the completion of its first Systems and Compliance Reviews with positive feedback. In May, the company announced its first area-specific certification plan was accepted by the agency.

Joby and Agility Prime: A Strategic Investment

In October 2020, AFWERX Agility Prime entered an agreement with Joby Aviation to gain insight into and ultimately support flight testing and FAA certification of the Joby eVTOL aircraft. This agreement supports Joby’s commercial business goals while simultaneously assessing utility against a variety of future Government use cases.

Joby hopes to debut its air taxi for commercial service as soon as 2024, offering a clean and quiet method of aerial transportation that tackles the twin problems of congestion and pollution in major metropolitan regions. Joby’s eVTOL aims to provide significant improvements in cost, reliability, and acoustics through the use of a distributed electric propulsion architecture and Simplified Vehicle Operations (SVO) technology.

Joby and Agility Prime have an ongoing contract to support flight testing of the company’s aircraft with an aim to further explore its flight envelope and drive greater understanding of the operations, reliability, and maintenance of eVTOL aircraft. Other government entities, including potential future customers, are currently in conversations with Joby.

The agreement between the Air Force and Joby is a symbiotic relationship. Joby gains access to unique test resources, such as wind tunnels and environmental testing facilities, while also benefiting from the knowledge of flight test experts from Agility Prime.

Likewise, the military is making a strategic investment that will provide the opportunity to evaluate Joby’s product (and eVTOL technology in general) for military utility. Joby’s aircraft could, for example, assist in mid-mile and last-mile logistics by delivering parts across a base, increasing speed and efficiency of maintenance actions while reducing operating costs. Additionally, the eVTOL could be an optimal tool for security forces and emergency response, including evacuating personnel from a disaster area. These aircraft could also be used for personnel transport between bases and military test and training ranges.

Joby, Uber, and the Air Taxi Mission

Some eVTOL companies intend to sell their aircraft to leasing companies or airlines, much like Boeing and Airbus do today. Joby instead plans to remain heavily vertically integrated and offer the transportation its aircraft enables as a commercial service: electric aerial ridesharing.

Joby has designed this service for everyone, not just those with deep pockets. Joby aims to set the price per mile significantly below today’s cost of helicopter transportation and move toward parity with current ground transportation as the service scales. Lower operating costs and reduced pilot training requirements will make these lower pricing options possible.

“Joby's marketing strategy isn't targeting the wealthy,” said Michael DeRespinis, AFWERX Agility Prime Program Manager for Joby. “They intend to make their service available to the same income population that would typically utilize Uber or Lyft service.”

While Joby hopes to launch their product for commercial use in 2024, that might be an optimistic timeline. There has been early and continuing engagement with the FAA on this new class of vehicle, and in 2020 Joby received a stage four G-1 Certification Basis from the agency, laying out the safety rules that apply to its aircraft – a major step toward certification. However, the FAA ensures the continued safety and efficiency of the commercial airspace through rigorously applied safety standards, and the agency will require Joby’s aircraft and other eVTOL aircraft to meet these standards in order to receive certification and operate commercially in the National Airspace System (NAS).

“The FAA is an inherently risk-averse organization, and for good reason,” DeRespinis said. “So while Joby will be required to meet these civil certification standards, as one of the leading eVTOL manufacturers in the US, Joby also has the obligation to support the FAA in determining where these standards need to be.”

However, innovations like Joby’s will benefit both civilians and the nation at large. The United States will become increasingly self-sufficient, able to manufacture and supply the resources necessary to stay ahead.

The possibilities are endless for both commercial and military use of the eVTOL. What about a rural mailman using a Joby aircraft to cut his delivery time in half?
As eVTOL technology progresses, Agility Prime will assist and monitor these exciting developments alongside companies like Joby as they reach and exceed their goals, one of which being reduced gridlock and increased productivity through harnessing cleaner energy sources.

“There are many companies that are currently posturing for market entry with their own eVTOL/hybrid eVTOL solutions in the personnel and cargo movement arena,” said DeRespinis. “When you take a close look at the resources currently involved in these two market sectors, then integrate eVTOL capability and the supporting infrastructure, then you can begin to see how this technology can radically change the world we live in. As an Air Force Program Manager for Agility Prime, I’m excited that the USAF has chosen to partner with industry in this journey.”