There are several conspiracy theories that involve aviation. The most famous of these involve the aliens of Roswell and the tragic events of September 11th. However, there is one conspiracy theory that has a measurable amount of believers that is easily refuted with the simple laws of science and statistics. This is, of course, chemtrails.

Those who subscribe to the Chemtrail theory believe that the entire aviation industry, military and civilian, are tasked by the U.S. government to spray artificial clouds high above the ground in our atmosphere with the intent of altering our climate or inoculating the population with inhalable drugs. This theory is based on the visible identification of the common aircraft contrail, and a reliance on the fallacy that it can be identified as something else.

So in a final sweeping motion, what do you say we explain-away this whole chemtrail thing after all, shall we?

The Science & History

When an organic material is burned, it will produce different compounds: soot, smoke, and various oxides. What is produced will vary depending on the material that was burned and the process in which it was burned. However there are two things that are generally universal in the burning of organics; water and carbon dioxide.

Generally, neither of these can be seen with the naked eye unless temperatures are cold and the steam condenses into visible water vapor. This is common from smoke stacks, the tailpipes of automobiles, or even your breath in the winter months.

The gasoline engine creates about one gallon of water for each gallon of gasoline consumed. When the engine is shut down, the remaining water oxidizes (or rusts) the exhaust and the engine’s cylinders. This limits the life of the exhaust system and the engine, but is not a major problem and is accepted as part of the normal process and life cycle of the internal combustion engine.

This water, seemingly innocuous, became lethal in the Second World War for the crews of the Boeing B-17 bomber. The four Wright turbocharged engines in the B-17 allowed it to climb above 30,000 feet. The humid exhaust of the engines quickly froze in the minus 40 degree air (temperatures become significantly colder at higher altitudes) leaving long white clouds behind the bombers indicating their presence and precise location to the German fighters. The safety of being at altitude was compromised by these telltale condensation trails, or contrails.

The military worked to find a solution and discovered that certain acidic compounds injected into the exhaust eliminated contrails. This solution became available after the conclusion of the war and was immediately obsolete with the advent of radar, which allowed airplanes to be “seen” regardless of the time of day or weather. This idea was later briefly resurrected with the Northrop B-2 stealth bomber, though ultimately not incorporated into the design.

The Commercial Jet Age

The post-war, high altitude commercial airliners typically operated around 25,000 feet. Only the low production Boeing 377, though still propeller-driven, could climb above 30,000 feet and was most commonly operated as an intercontinental airliner. Because of this, contrails were rarely seen in the United States prior to the 1960s.

The year 1958 was a watershed year in commercial aviation. Boeing introduced the 707 and Douglas the DC-8, while a year later Convair debuted the 880. The turbojet engines on these airliners thrived in the cold thin air found above 30,000 feet and they were routinely operated in these flight levels. In the 1960’s, contrails became commonplace across the United States, especially along designated jet airways between ground based navigation aids. When the temperature is low enough and the humidity high enough, the 1,500 gallons of water produced every hour by these jetliners was transformed into four cirrus clouds.

When the humidity is very high, the contrails will remain for hours. In moderate humidity the contrails may last only a few seconds as the ice is absorbed into the atmosphere in a process known as sublimation. If the humidity is very low, the water vapor will immediately be absorbed into the atmosphere leaving the sky clear of contrails. Although the engines are producing numerous chemical compounds from the combustion of jet fuel, the only one that can be seen at altitude is H 2 0 in a frozen state.

The fuel burned in these engines is Jet-A, similar to kerosene, diesel fuel, and home heating oil, but formulated specifically for aviation use and the extreme environmental conditions that are routine on every flight. Turbojet engines will generally run on any petroleum fuel including gasoline, but are optimized for Jet-A and derivatives. The other chemical compounds from the combustion process include CO 2 , soot, and various other monoxides and dioxides very similar to that of diesel exhaust. The difference is mostly limited to water exhausted, which as explained, at altitude turns to ice.

These man made cirrus clouds reflect sunlight during the daytime and cool the planet. At night these clouds reflect the escaping heat and limit the drop in overnight temperatures. During the week after September 11, 2001 when all air traffic was grounded in the United States, there was some very limited data available on the extent of this effect for scientists to analyze.

On rare occasions at low altitude when the humidity is at or near 100%, an aircraft may generate another kind of contrail. This one is commonly seen on airliners that are landing in poor visibility conditions with high humidity:

The wing generates a low-pressure area above its surface which is a component of the lift that it produces. Beneath the wing is a higher pressure area which often escapes to the wing’s surface at the wingtips and between the sections of the flaps. When this occurs, a vortex is generated, which is also the source of wake turbulence. The air pressure in these vortices is below that of the surrounding atmosphere, and with a drop in air pressure, there will be a corresponding drop in temperature. If the temperature drops below the dew point, the water will come out of solution, i.e. condense, and will have the appearance of a cloud or fog (via feller at dhead inc). The dramatic result is a tubular like cloud coming from between the flaps. It can also occasionally be seen at the wingtips, propeller tips, or blanketing the top of the wing in the low-pressure area.

The Conspiracy Theory

The chemtrail movement considers contrails not to be by-products of the jet engine (or wing), but deliberate action by the United States government to modify the climate or inoculate the population. The conspiracy is by the government’s behest, and implemented by the military, the nation’s airlines, the petroleum companies, and the tens (or hundreds) of thousands of employees of each entity.

This movement terms these man-made cirrus clouds “chemtrails”, and claims to be able to identify the difference between them and contrails. It identifies days that the program is in operation, areas of focus, and proof of additionally installed equipment on aircraft.

The movement is a group of people that wishes to be deceived, and fueled by very small group that enjoys the deception. Doctored photos of static wicks, pictures of lavatory and galley plumbing presented as chemtrail applicators, and stories from people claiming to be mechanics, pilots, and ramp workers all stoke the fires these people hold true. Some have even created “chemtrail forecasts” based off of actual weather data.

People living in rural areas near ground based navigational aids feel they are being targeted. However, the volume of aircraft overhead, and thus the potential for contrails, is primarily due to their proximity to the aforementioned navigational aids. Others claim to feel immediate effects from these chemtrails six miles above. However in reality, the condensation is quickly being blown clear of the area by winds in the upper atmosphere that typically blow at around 100 miles per hour.

And above all they notice all these minute details, yet fail to see how impossible it is to maintain a conspiracy when hundreds of thousands of people would need to be involved, several airlines, and at least two departments of the United States. They also ignore the contrails that are found outside the United States.

The deception isn’t by the government and all the bodies involved, but by a distinctly small group of people relishing in the enjoyment of a game, and fueling the world’s largest conspiracy that isn’t.

John Steffen is a former airline pilot and aviation expert and historian currently residing in New York.

Phil Derner founded NYCAviation in 2003. A lifetime aviation enthusiast that grew up across the water from La Guardia Airport, Phil has a background in online advertising and airline experience as a Loadmaster, Operations Controller and Flight Dispatcher. You can reach him at [email protected] or follow him on Twitter at @PhilDernerJr.