The first ever scheduled commercial air passenger flight took place in 1914 in the US. The flight was 23 minutes long and flew the distance from St. Petersburg to Tampa. Only one seat was available in this aircraft, and it was auctioned for $400 USD (over $5,000 today). Since then the aviation industry has come leaps and bounds, especially in terms of technology and safety, for which it is often held up as a leading example.
Today, aviation is considered as one of the safest modes of transportation. In fact, year 2017 has been the safest for aviation so far. There were 4,093 million air passengers in 2017 with absolutely no recorded commercial passenger jet deaths.
So, when we look at safety records across different industries today, you cannot but wonder the following: how has flying become so safe?
This blog post is the fruit of my curiosity. A few weeks ago, I was on a domestic flight on my way from Mexico City to Guadalajara. This was one of the most uncomfortable journeys I’ve ever experienced in the air, with a two hour delay in departure, constant turbulence, and to top it all off, a thunder storm surrounding us 80% of the time. After about 15 minutes in the air, our aircraft was hit by lightning (I was assured by cabin crew that this was very common in the region), which to my surprise caused very little disturbance to the plane. The lights in the cabin flickered a few times as we saw and felt the lightning flash.
After getting over my panic mode and landing safely as planned, I became curious about what happens when an airplane is hit by lightning, and whether this natural phenomenon can cause a plane to crash.
As a result of my research, I was surprised not only by how safe it is to fly but also by what the most common causes for aviation accidents actually are.
In aviation, lightning strikes are actually very common. In the US, it’s estimated that each commercial plane is hit by lightning at least once every year.
Lightning is most common near the equator, whereas the least lightning activity occurs over the oceans and polar areas. Lightning is also more likely to strike in near zero temperatures and in the presence of rain. Most lightning strikes take place during the climb and descent phases of the flight as lightning activity is more prevalent in the altitude between 5,000 and 15,000 feet (1,524-4,572 meters).
The worst commercial plane crash caused by a lightning strike took place in Peru in 1971 when lightning hit one of the fuel tanks and tore the right wing of the plane off. The flight crashed on the ground in the middle of the Amazon rainforest and killing all 91 passengers except one. Today, airplanes go through rigorous testing to make sure they’re safe and prepared for such events. Aircrafts are equipped with highly advanced lightning protection, which should prevent any serious incident from happening.
Smaller aircrafts that don’t carry passengers are not as vulnerable to lightning because their skin is made of aluminium and they don’t contain computerized engine and flight controls.
When lightning strikes the aircraft, it’ll first attach to an extremity; the nose or wing tip, for example. All the surfaces of an aircraft are bonded, which makes the electricity current travel through the exterior skin and structures of the aircraft, and exit to the air from another extremity. (see image)
Image from Boeing’s website: http://www.boeing.com/commercial/aeromagazine/articles/2012_q4/4/
Although protected from lightning strikes, airplanes can be damaged by them. After a lightning strike the aircraft is inspected, and damage such as scratches to the skin of the aircraft will be repaired. Follow up actions (such as inspections, testing and clearance) after this type of incidents are vital.
To prevent lightning from causing damage to the essential equipment of the aircraft, a lightning engineer makes sure that they’re well-protected. Lightning (conductor) engineers work not only in aviation but also in other industries. In the UK, the British Standard 6651-1000 specifies the code of practice for protection of structures against lightning.
The aircraft’s nose cone is protected with lightning diverter slips that are applied on the outer surface of the area. The cone contains radar and other essential flight instruments and must therefore be well-protected.
In the fuel system even the smallest spark can cause a disaster. Consequently, the skin around the fuel tanks in the wings is made extra thick so that it can withstand a burn-through. The lightning protection engineer must also make sure that interior equipment (wires, computers and other instruments that control the aircraft) is protected from the current. Nowadays, it is also common to use fuels that produce less explosive vapours.
All essential equipment in an aircraft must be verified by the manufacturers to be protected against lightning in line with regulations set by the authority of the aircraft’s origin (such as the Federal Aviation Administration).
Aviation technology has come a long way. The worst ever airplane crash took place in Tenerife, Spain in 1977. 583 people lost their lives when two aircrafts (KLM Boeing 747 and Pan Am 747) collided in the runway. The KLM flight was attempting to take-off without clearance whilst the Pan Am aircraft was landing. Foggy weather conditions, pilot error and poor radio communication from the tower have been cited as the main reasons for the incident; however, human error can also added to the list as the pilot should have waited for clear orders despite the bad radio connection to the tower.
So, although factors such as bad weather, ice and snow, and failed engines might be the first things in your mind when thinking of reasons why planes crash, it’s in fact human error that is the most common cause of airplane incidents. According to the FAA, “80% of accidents and events are contributed to human error”.
And this statistic shouldn’t be surprising. According to SHP Online, around 90% of all “industrial accident reports indicate a failure on the part of the injured person or a co-worker”. Also, an injury investigation study by the University of California concluded that 73% of trips and falls (OSHA’s most reported incident type) were caused by the subject being either inattentive or distracted.
The worst mid-air collision in 1996 occurred due to the pilot of Air Kazakhstani flying below the advised clearance altitude. This caused the plane to crash with another commercial flight above India. No passengers survived.
You might have also heard of another very recent incident involving a British Airways flight heading to Mauritius. In January 2018, the pilot was removed from the plane before take-off as it was suspected that he was under the influence of alcohol.
These examples demonstrate that pilots are only humans, and that without the technological advancements and the research and development put towards aviation safety, flying wouldn’t be as safe as it is today.
Although the emphasis here is put on human error, let’s not forget about all those flights that have been saved by the pilot.
In 2009, the US Airways Airbus A320 made an emergency landing to New York’s Hudson River. The pilot, Chesley Sullenberger was able to make a safe landing along the river just minutes after taking off from La Guardia airport after the left engine of the aircraft was disabled by a flock of birds. No technological advancement could have saved the aircraft from crashing in the middle of the city.
In April 2018, a Southwest Airlines flight, that took off from the same airport (La Guardia), was forced to do an emergency landing in Philadelphia. The incident was caused by an engine failure, causing a piece of fuselage to break loose before breaking a cabin window. Tragically, the passenger was partially sucked out of the window and suffered fatal injuries. The captain of the plane, Tammie Jo Shults, managed to bring the plane down safely 40 minutes after the explosion. The pilot was then lauded as a hero, but she said she was just doing her job (pilots are well aware that they are responsible for the safety of hundreds of souls, both the crew and passengers).
A lot of effort and research goes towards improving human performance and reducing human error in aviation. This could be something that all industries should focus on.
The Human Factors Division of FAA “provides scientific and technical support for the civil aviation human factors research program and for human factors applications in acquisition, certification, regulation, and standards.” The department conducts research on human factors and human performance, which is then applied to equipment, systems, procedures, jobs, environments, training, facilities, and so on (Role of Human Factors in the FAA).
In this video, we can see the different departments, people, skills and effort that goes into keeping aviation safe: https://www.faa.gov/tv/?mediaId=1831. It’s impressive how many job roles there are and how specific the knowledge and skills are that they each require.
Although airplane accidents are rare, not all countries have had the same level of regulatory enforcement, and incidents are more common in certain regions. For example, Russia has hosted its fair share of global air traffic incidents. The country doesn’t lead the charts, however.
Since the year 1945, the United States has had the most accidents and fatalities in its air traffic. Russia is in second place followed by Brazil, Canada, Colombia and the UK (6th place). Although, the order of the list doesn’t take into consideration the number of flights that take place in the country: the US has the busiest commercial air travel globe in the world, which contributes to the number of accidents it’s had.
Despite the excellent advancements in safety, not all accidents are unintentional.
In July 2014, a Malaysian Airlines flight MH17 was hit by a Russian missile in the eastern conflict part of Ukraine. The event spurred a politically heated discourse; however, the aircraft’s black box was able to demonstrate that before it crashed down, all engine parameters were normal. This indicates that it was the missile (proven to have been manufactured in Russia) that took the plane down.
Other well-known intentional incidents in the aviation industry include the airplanes involved in 9/11 and the crash of a Pacific Air Lines flight 773 (1974) caused by a passenger shooting the pilot.
A retired pilot John Cox says that it is the continuous effort each department has put to improve safety that has made the industry so safe.
Learning from past events and mistakes is one of the main reasons why the industry has been able to improve its performance year after year. The black box is one of the key contributors to the wide range of data aviation has been able record from its incidents.
Aviation is also squarely on the public’s radar, which might be one of the reasons the industry has invested in safety excellence. Air traffic incidents impact hundreds of people and get lot of publicity in the media, so company reputation is hugely at risk. Additionally, there is heavy investment in and reliance on the industry by global companies who couldn’t conduct international business nearly as easily without aviation’s success in safety. In other words, stakeholders have significant influence over the aviation industry as millions worldwide are directly impacted by it, which will likely have contributed to the stringent safety procedures in the sector.
The black box is the golden key to an incident investigation. This orange “box” is in fact a cylinder consisting of two parts: a flight data recorder (FDR) and a cockpit voice recorder (CVR). These are placed at the rear of the plane. Black box records parameters from the flight systems (e.g. airspeed, fuel flow etc). The impact of an event, such as the effects of a lightning strike, is recorded by the FDR. The CVR records all speech in the plane’s cockpit and the interphone communications including public address messages from the crew to the passengers. It’s obligatory to have a black box on all commercial flights and corporate jets.
All critical data from the black box has allowed investigators to study the leading cause(s) to an incident. This data is then being used for monitoring and learning.
Learning and investigating past events has allowed aviation to improve safety, and it’s one of the key points health and safety in other industries can learn from. By following the effort aviation puts towards improving its safety practices, other industries can follow suit to change the odds of an incident occurring:
“You're more likely to be killed by a strike of lightning, a dog attack, an earthquake, and even an asteroid impact across your lifetime than in an airplane crash.” (Business Insider UK)
With strict regulations and technical improvement, planes have become the safest mode of transportation. Every incident, error and near miss is recorded, and changes are made to prevent these from happening again. With critical data in their hands, the industry has made travelling easy and less time-consuming, and it has elevated international trade to a whole new level.