GOP Jet-setters in Climate Denial: It is getting too Hot for your Plane to take Off

By Ethan Coffel | (The Conversation) | – –

Hot weather has forced dozens of commercial flights to be canceled at airports in the Southwest this summer. This flight-disrupting heat is a warning sign. Climate change is projected to have far-reaching repercussions – including sea level rise inundating cities and shifting weather patterns causing long-term declines in agricultural yields. And there is evidence that it is beginning to affect the takeoff performance of commercial aircraft, with potential effects on airline costs.

National and global transportation systems and the economic activity they support have been optimized for the climate in which it all developed: Machines are designed to operate in common temperature ranges, logistical plans depend on historical weather patterns and coastal land development is based on known flood zones. In the aviation sector, airports and aircraft are designed for the weather conditions experienced historically. Because the climate is changing, even fundamental infrastructure elements like airports and key economic sectors like air transportation may need to be redesigned and reengineered.

As scientists focused on the impacts of climate change and extreme weather on human society and natural ecosystems around the world, our research has quantified how extreme heat associated with our warming climate may affect flights around the world. We’ve found that major airports from New York to Dubai to Bangkok will see more frequent takeoff weight restrictions in the coming decades due to increasingly common hot temperatures.

Climate changes flights

There is robust evidence that extreme events such as heat waves and coastal flooding are happening with greater frequency and intensity than just a few decades ago. And if we fail to reduce greenhouse gas emissions significantly in the next few decades, the frequency and intensity of these extremes is projected to increase dramatically.

The effects on aviation may be widespread. Many airports are built near sea level, putting them at risk of more frequent flooding as oceans rise. The frequency and intensity of air turbulence may increase in some regions due to strengthening high-altitude winds. Stronger winds would force airlines and pilots to modify flight lengths and routings, potentially increasing fuel consumption.

The July heat-related Phoenix flight cancellations happened at least in part because airlines’ operational manuals didn’t include information for temperatures above 118 degrees Fahrenheit – because that kind of heat is historically uncommon. It’s another example of how procedures may need to be updated to adapt to a warmer climate.

Flying in the heat

High air temperatures affect the physics of how aircraft fly, meaning aircraft takeoff performance can be impaired on hot days. The amount of lift that an airplane wing generates is affected by the density of the air. Air density in turn depends mostly on air temperature and elevation; higher temperatures and higher elevations both reduce density.

Hot air is less dense than cooler air. That affects the amount of lift an airplane can generate.
The Conversation (via Piktochart), CC BY-ND

The lower the air density, the faster an airplane must travel to produce enough lift to take off. It takes more runway to reach a higher speed, and depending on how long the airport’s runway is, some airplanes might risk running out of room before reaching sufficient speed. When this occurs, the only immediate option is to reduce the aircraft’s weight to lower its required takeoff speed – by removing passengers, luggage and cargo. This is referred to as a weight restriction.

Weight restrictions happen now, especially in hot places like Phoenix and Dubai and at airports with short runways like New York’s LaGuardia and Washington, D.C.‘s Reagan National, but our research suggests that they may become much more common in the future.

Global temperatures have been steadily rising for decades, and they will almost certainly continue to do so. In some regions, there is evidence that the hottest temperatures may increase at a faster rate than the average, further stacking the deck in favor of extreme heat. These hotter temperatures will reduce air density and make it much more likely weight restrictions are needed for flights taking off during the hottest parts of the day.

The frequency and magnitude of weight restrictions is projected to increase – in some locations, the number of days requiring at least some amount of weight restriction for certain aircraft could double or triple, perhaps covering 50 or more days per year.

The economics of adaptation

On most affected flights, the amount of cargo, passengers and fuel that must be removed to allow for takeoff will usually be small – between 0.5 percent and 4 percent of the total load. That means fewer paying customers on airplanes, and less cargo on board. When those restrictions add up across the global air transport system, the costs can be significant.

Carrying just a fraction of a percent fewer passengers or less cargo can add up to millions of dollars in lost revenue for an airline over years of operation. That makes even small weight restrictions a concern in such a highly competitive and optimized industry. These limits could disproportionately affect long-haul flights, which require large fuel loads and often take off near their maximum weights.

There are ways that airlines could mitigate increasing weight restrictions. The most feasible is to reschedule some flights to cooler hours of the day – although with air traffic increasing and many airports already operating near capacity, this could prove difficult.

Another potential solution is to build longer runways. But that’s not always possible: Some airports, like New York’s LaGuardia, are on coastlines or in dense urban environments. Even where a longer runway is technically possible, buying the land and expanding an airport’s physical area may be expensive and politically difficult.

Aircraft could be optimized for takeoff performance, but redesigning aircraft is extremely expensive and can take decades. Manufacturers are always working to build planes that are lighter and more fuel-efficient. In the future, those efficiency improvements will be necessary just to maintain today’s performance.

Broader implications

These changes are merely examples of the countless procedures, processes and equipment requirements that will have to be adjusted for a changing climate. Even if those adaptations are successful, they will take effort and money to achieve.

The ConversationMany sectors of the economy, including the aviation industry, have yet to seriously consider the effects of climate change. The sooner, the better: Both airport construction and aircraft design take decades, and have lasting effects. Today’s newest planes may well be flying in 40 or 50 years, and their replacements are being designed now. The earlier climate impacts are understood and appreciated, the more effective and less costly adaptations can be. Those adaptations may even include innovative ways to dramatically reduce climate-altering emissions across the aviation sector, which would help reduce the problem while also responding to it.

Ethan Coffel, Ph.D. Student in Earth & Environmental Sciences, Columbia University and Radley Horton, Associate Research Scientist, Center for Climate Systems Research, Columbia University

This article was originally published on The Conversation. Read the original article.


Related video added by Juan Cole:

ABC15 Arizona: “Why can’t planes fly when it’s so hot?”

3 Responses

  1. Trump’s NASA budget, a $561 million decrease over previously enacted levels which significantly reduces the number of Earth science climate study missions is also eliminating the agency’s education office. And as ordained by bigotry, do away with Obama administration plans to robotically retrieve a piece of Martian asteroid as a precursor to eventual landings on Mars.

    link to

    But there is funding for a Planetary Protection Officer, a candidate with a SECRET security clearance to ensure that alien life, or “organic-constituent and biological contamination” does not become a resident on Earth. The position will pay: $124,406 to $187,000 annually. 

    link to

    NASA funding to better understand climate change, strangled. Funding for a person with a SECRET security clearance to protect us from alien invasions, no problem.

    This is not satire.

  2. Flying into Phoenix, Las Vegas and other desert airports has always been a “thrill ride” during the summer due to the uneven heating of the surfaces leading to invisible thermal towers causing lift shear in the flight paths. The additional heating is causing the “thrill ride ” to become worse.

    As for the lift problem, it can be very hard to deal with. Many years ago I was working for the USAF at Hill Field near SLC. The altitude is about 5000 feet and during the summer we had lots of problems getting DC-9 air freighters launched. The birds would arrive empty all day long and get loaded. Even though we had 2.6 mile runway (~13.5K feet – enough for a B-52), the planes could not get enough lift if the surface temperature was over 90F, so the planes were parked on the old B-52 parking spots until the sun went down. Then we would drive the length of the runway taking the temperature to calculate the air density. once the air density was sufficient to launch a bird, we sent one off. The aircraft would taxi to the extreme north end of the runway, put on their brakes and run up the engine to max power. When the tires started to skid, the brakes would be released and the aircraft would travel toward the houses at the south end of the runway. The pilot would hold the aircraft nose down to maximize the speed then just before the south fence, the pilot would gently raise the nose to just clear the fence and houses and slowly fly off. This is know as a combat take-off and airlines only use it at a few airports due to the fear it induces in the passengers. When I was flying much smaller and lighter aircraft in Vietnam we used a similar technique to get as high as possible, as fast as possible, to minimize aircraft damage from ground fire – it was always a “fun ride.”

    Some technical notes . . .

    – The newer wings on commercial aircraft are already optimized for lift and economy, so there is very little that can be done to improve the aircraft wing performance in low density air. Buying new aircraft or replacing the wings will not be a good economic option.

    – Not only is lift lost , but so is propulsion. the turbofan engines lose a lot of power when the intake air temperature is so high. At altitude where the air is often near or below freezing the performance will be better, but the aircraft has to go through a lot of hot air to get there.

    – As noted, runways are difficult to extend, BUT note that Hill field has a very long runway and we still had to wait until after sundown to launch the birds and used the ENTIRE length of the runway to get loaded DC-9 freighters into the air.

    – The only viable option for the airlines is to limit weight by leaving some passengers or freight behind or under-fueling the aircraft and adding a fueling stop to a normal non-stop.

    The bottom line is more expensive travel to hot areas.

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