![]() The CMIP5 ensemble has been shown to represent extreme temperature events relatively well ( Sillmann et al. The 737-800 is one of the most common short-to-medium-range aircraft, operating 426 789 flights in 2013 ( The trends we find here hold with some variation for other commercial aircraft types. We use the period May–September rather than the standard June–August in order to capture the vast majority of weight-restriction events in the future. Here we investigate how the number of days per summer (May–September) on which a Boeing 737-800 must be weight restricted may change during the twenty-first century as a result of climate change. Airlines respond by removing either passengers or cargo to decrease the aircraft’s weight and thus lower its takeoff speed. For each airport and aircraft type, there is a temperature threshold above which the airplane’s minimum flying speed at its maximum takeoff weight is too high to reach on the available runway, and the airplane must be weight restricted. Barometric pressure variations are used in day-to-day flight planning, but since weather-related pressure changes are usually less than 30 hPa at all airports worldwide, this is a much smaller factor than temperature and is not considered here all performance data assume a standard pressure of 1013 hPa. As a result, on warm summer days, commercial airplanes have higher takeoff speeds ( Anderson 1999). As air warms at constant pressure it becomes less dense, and an airplane wing traveling through this thinner air will produce less lift at a given speed than in cooler, thicker air. Here we quantify the expected impact of increasing mean and extreme temperatures on aircraft performance. ![]() Thus far, few studies have investigated the effects of climate change on aviation-relevant weather parameters ( Williams and Joshi 2013). 2002) and costing airlines hundreds of millions of dollars per year in lost revenue ( Lan et al. Weather is the most significant factor affecting aircraft operations, accounting for 70%–80% of passenger delays ( Rosenberger et al. ![]() 2010), with potentially larger changes in the magnitude of extreme events ( Fischer et al. As climate change progresses, temperatures are projected to increase, with approximately 4°–5☌ of mean warming expected by 2100 under the RCP8.5 emissions scenario ( Hartmann et al. Extreme temperature events have been observed to increase more rapidly than the mean, with changes of 1°–1.5☌ over much of the continental United States ( Brown et al. 2009), with the most significant changes occurring in the central and eastern United States ( Walsh et al. Temperature increases exhibit spatial variation ( Portmann et al. Surface temperatures over the United States have increased by approximately 0.8☌ since the start of the twentieth century, with most of that change occurring after 1980 ( Walsh et al. Planning for changes in extreme heat events will help the aviation industry to reduce its vulnerability to this aspect of climate change. Increased weight restrictions have previously been identified as potential impacts of climate change, but this study is the first to quantify the effect of higher temperatures on commercial aviation. These performance reductions may have a negative economic effect on the airline industry. For a Boeing 737-800 aircraft, it was found that the number of weight-restriction days between May and September will increase by 50%–200% at four major airports in the United States by 2050–70 under the RCP8.5 emissions scenario. These changes will negatively affect aircraft performance, leading to increased weight restrictions, especially at airports with short runways and little room to expand. Climate change is projected to increase mean temperatures at all airports and to significantly increase the frequency and severity of extreme heat events at some. The number of summer days necessitating weight restriction has increased since 1980 along with the observed increase in surface temperature. For a given runway length, airport elevation, and aircraft type, there is a temperature threshold above which the airplane cannot take off at its maximum weight and thus must be weight restricted. Temperature and airport elevation significantly influence the maximum allowable takeoff weight of an aircraft by changing the surface air density and thus the lift produced at a given speed.
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