Nobody wants to get on an uncomfortable plane. NASA’s research could help the emerging industry of air taxis (small vertical takeoff and landing aircraft intended for short trips) understand the relationship between comfort and willingness to fly.

That’s where NASA comes in, with data that can help identify how to plan air taxi trips that can make travelers feel good.

NASA was able to gather that data by putting its own employees through some difficult virtual flights. At the agency’s Armstrong Flight Research Center in Edwards, California, volunteers have been placing themselves in a virtual reality motion simulator to experience the sudden shifts and tilts that tomorrow’s air taxis might encounter, showing researchers that those moments are felt from a passenger’s point of view.

Their reactions are giving NASA new insights into how aircraft motion influences comfort and confidence in flight; for example, that certain types of large, sudden movements can be especially annoying. Using that data, the team developed new models that link those sudden movements to passengers’ willingness to fly. The models can help guide future aircraft design and flight operations, allowing producers to know which maneuvers will be too jarring for future air taxi passengers.

Large, sudden movements can also be caused by gusts of wind or landings. NASA data allows researchers to estimate when passengers may begin to feel uncomfortable as movement increases, giving them the ability to shape aircraft designs and operations to minimize the impact of those situations.

“Through this study and others, we are beginning to identify passenger comfort thresholds for aggressive flight movements,” said Curtis Hanson, NASA’s Armstrong principal investigator for this effort. “We can start making predictions about how air taxis should fly so that the majority of passengers enjoy the experience and want to travel again, which will benefit the public and the industry.”

In the simulator, each participant experienced four levels in which their plane pitched up and down, banked side to side, turned, or accelerated rapidly to climb or descend during flights from downtown San Francisco to Alcatraz Island in California. Even moderate changes in these movements reduced comfort for some participants, while others remained comfortable at higher levels. Participants rated each flight on a five-point scale and identified which movements they found uncomfortable.

Participants were asked if they would take a real air taxi flight with movements that were uncomfortable for them. Their responses suggested that today’s travelers may be less tolerant of sudden movements than airline passengers of 50 years ago, based on comparisons with previous NASA research on ride quality.

These latest comments are based on a multi-year NASA study to better understand air taxi passenger comfort. The overall research effort found clear relationships between specific aircraft movements and the comfort people feel during flight.

This work is currently being carried out under the Subsonic Vehicle Tools and Technologies project in NASA’s Research and Technology Mission Directorate and contributes to the agency’s advanced air mobility research.