eVTOLs Gone in the Wind?
Headwinds, Tailwinds, and Crosswinds Key Concerns for Uncrewed Aerial Vehicles
If you’ve ever flown on a commercial airliner, you might have heard the pilot announce there was some turbulence ahead and consequently, the crew in the flight deck would adjust their route to minimize its effects on the ride.
In an urban environment – such as the ones passengers onboard eVTOLs and other, uncrewed aerial vehicles (UAVs) will face – wind will be a considerably larger factor than in conventional air travel. Urban flight corridors are tight; updrafts, downdrafts, and crosswinds require better forecasting and strategies to cope with rapidly shifting wind patterns.
How eVTOLs Will Outwit the Wind
To get ahead of the winds eVTOLS will face, NASA funded “Demonstration of the In-Time Learning-Based Safety Management for Scalable Heterogeneous AAM Operations,” a study to better understand the challenges and propose viable solutions to wind hazards.
Researchers from George Washington University, Vanderbilt University, University of Texas at Austin, and MIT Lincoln Laboratory looked at three aspects of how wind conditions will impact eVTOLs: (i) adverse weather with a special focus on winds, (ii) eVTOL vehicle and component level faults/degradation, and (iii) AAM corridor incursion by non-cooperative aircraft. Individually, each of these factors pose unique challenges; collectively, any two, or all three hazards, pose additional factors for the safe operation of eVTOLs in urban environments.
Building on findings from the Single European Sky ATM Research (SESAR), the research team analyzed wind hazard impacts on the aircraft and the surrounding airspace. They considered operational performance, component faults and degradation, nonconformance, and non-cooperation. Each aspect impacts performance, but they also have the potential to lead to a cascading degradation effect on the entire system. Battery degradation, such that it requires an eVTOL to swap out batteries, for example, can cause unexpected delays leading to intended landing pads becoming temporarily unavailable.
Sudden, unexpected, severe wind conditions might result in the need to close off regions of airspace. That could result in delays for departing aircraft and the need to redirect eVTOLs already enroute to a different vertiport. The team broke down hazards into three types: mission-level hazards, vehicle-level hazards, and airspace-level hazards.
To address these needs, the team proposed an in-time learning-based aviation safety management system (ILASMS) suitable for scalable heterogeneous AAM operations.
Looking at data from 2003-2007, a FAA study concluded that 53.6% of crewed, weather-related aviation accidents were caused by wind – a factor 35% higher than any other cause. The prominent role wind plays in adversely affecting safety – especially when it comes to lighter-weight aircraft with smaller propulsion capabilities (i.e., eVTOLs) – means the importance and urgency of this type of research and its findings will only increase as urban/advanced air mobility moves from futuristic concept to commonplace reality, safely and efficiently.
[Read the full paper here.]