Two recent flights, using the Boeing 737 max eight aircraft crashed due to similar altitude fluctuations, killing everyone on board. We tend to hear that flying is extremely safe But why do some planes crash and is there a safest seat that you can choose or a safest time of day to fly? Commercial flights are incredibly safe. In 2017, there was one fatal accident for every 16 million flights. But small private planes crash at rates similar to cars. The majority of the accidents are due to the pilot losing control or controlled flight into terrain, meaning the pilot didn’t see the ground a mountain or another obstacle until it was too late. In general amateur pilots have significantly less training and looser rules than commercial pilots. For commercial flights, according to the Bureau of Aircraft Accidents archives, there were 1,182 accidents between the years 2010 to 2018. The reason for these accidents can be broken down into four main categories: human error, weather, mechanical error, and sabotage. Human error is the cause of the majority of crashes. Using data from 1,020 commercial flight accidents these errors were predominantly skill based errors and decision errors. Skill based errors include not conducting proper visual scans, accidentally turning on or off switches, and not complying with checklists. A pre-flight checklist is a list of tasks to be performed by the pilot and crew before takeoff and this can significantly reduce risk. A 2014 crash that killed seven people could have been prevented if they had completed the pre-flight checklist and released a piece of equipment, the gust lock, before takeoff. Decision errors are conscious choices that result in poor outcomes. For example, once the pilots of that same flight realized the problem with the gust locks, they unsuccessfully tried to disengage the equipment, instead of stopping the flight. Human error can be minimized with adequate sleep. For example, a study of 435 pilots found that 90% experienced fatigue and another study found an increased probability of accidents as the duty time increased. A separate study of American plane accidents from 1982 to 2013 found that a quarter were related to weather. The most fatal weather conditions are precipitation, low cloud cover, and fog all of which impact visibility. The most lethal months to travel are December and January. One of the deadliest crashes occurred in 1977, when two Boeing 747s collided into one another on the runway during a period of thick fog; 583 people died. Other studies have found that these weather conditions often involve pilots pushing the aircraft and themselves beyond their limit; for example, Scud running, where a pilot lowers altitude to avoid flying in the clouds, or get-home-itis, where the pilot desires to get home quickly and overrides their sound decision-making. Mechanical errors are involved in 23% of fatal accidents. The main problem being engine failure. However, this is far less likely to occur in large jet aircrafts than in smaller propeller planes. For example, an Air France Airbus crashed killing all 228 passengers and crew due to a frozen pitot tube. Pitot tubes are sensors on the side of the plane, used to measure airspeed but when they froze over, they gave inconsistent readings. Not knowing the speed of your plane can result in deadly outcomes where you might under-speed, which can lead to stalling, or over-speed, where the aircraft will start to break apart as the structure isn’t meant for such high speeds. Finally, the most unlikely cause of a crash is sabotage, accounting for 7% of airplane fatalities. These do include the September 11th terrorist attacks. However, these types of incidents were the highest in China. Is there anything you can do to increase your chance of survival if you were in a crash? A 2007 article by Popular Mechanics analyzed every commercial plane crash in the United States since 1971 and found that those in the back of the plane had a 69% chance of survival compared to a 49% chance when you’re sitting at the front. In 2012, an uncrewed Boeing 727 filled with crash test dummies found similar results. The front wasn’t the best place to sit. This is why we have the black box, a highly protected box resistant to fire and explosion that records data and cockpit audio, and it’s located at the back of the plane. This data has been very helpful in linking the tragic Ethiopian Airlines flight 302 to the Indonesian Lion Air flight 610, where in both cases altitudes fluctuated sharply. Learning from these black boxes helps minimize these horrifying events and, though devastating, it is important to remember that air travel remains our safest means of transportation. Thank you so much for watching. You can click over there to watch our video what would happen if your plane door burst open mid-flight? It’s horrifying. Also, if you want to keep up to date on the latest science news and scientific takes on controversial topics, make sure to check out our podcast sidenote. We put links over there and in the description as well. Our latest episode was about vaccines. Make sure you subscribe for more science videos every Thursday and we’ll see you next week.