Implications of Wind Changes and Cross Wind Hazard Exposures at California Airports for Regional Air Mobility

California has a large number of public airports, including single-runway general aviation airports and small commercial airports. Because of anticipated changes in future temperature and precipitation in California (CA) and their effect on airports, our study raises a related question: will airports in CA experience any significant changes in wind direction and speed? This issue is especially important to address at single-runway airports where the occurrence of crosswinds exceed 10.5kn. Under such crosswind conditions, it is not safe for smaller/lighter aircraft to land and take-off. Conducting wind analyses by using historical data to estimate trends in wind speed and direction can provide deeper understanding of safety of operations. Because the concept of Regional Air Mobility (RAM) will focus on operations of smaller aircraft at regional (i.e. smaller) airports, it is important to evaluate the impact of crosswind on safety of RAM operations. Because each aircraft has unique maximum demonstrated crosswind characteristics, as set by the FAA, we conduct the following analyses/tasks: (1) probability of crosswind occurrences that include speeds greater than or equal to 10.5kn at CA airports on individual runways; (2) probability of crosswind occurrence greater than or equal to 10.5kn at single-runway airports, and demand for each relevant aircraft design group and aircraft approach speed; and (3) probability of aircraft incidents during higher than allowed crosswind speeds for corresponding aircraft design group and aircraft approach speed. Our analysis results for task (1) reveal a significant California's crosswind hazard exposure at the runway level. Analysis results for tasks (2) and (3) indicate that out of 65 runways assessed, six have probabilities of incident greater than 0.005, while single-runway airports CRQ and SMO are prone to crosswind incidents given their A-I fleet. In addition, the probability of crosswind incidents at airports with B-I fleet mix is much higher than those for A-I fleet mix. Therefore, a crosswind hazard exposure at the runway and airport level in CA will negatively impact operations of RAM fleets.