Thankfully, no one was injured when a large hole was ripped in an engine of a China Eastern Airlines plane an hour after it left Sydney bound for Shanghai this June. Although the incident was certainly scary for those on board, the Airbus 330-200 showed it was more than capable of flying and landing safely with just one of its two engines operational.
Although you might be alarmed every time you hear of an accident involving an airplane, it might be comforting to know that 2016 was the second safest year in aviation history, after 2013, according to the latest figures from the Aviation Safety Network. It worked out at around one death per 10,769,230 passengers flown.
Since the 1970s, the worst decade for fatal accidents involving passenger aircraft, there has been a steady and persistent decline in accidents, thanks to advances in technology and increased safety precautions. Here are some of the things that have contributed to airline safety.
Pilot training and redundant aircraft systems
Pilots undergo rigorous training to obtain their Commercial Pilot Licence, followed by yet more training if they want to be the captain of a aircraft or be part of a flight team on a large plane. Then there are regular multi-day courses of simulator training on the latest machines, to learn how to deal with things like engine failures and fires, hydraulic and brake malfunctions, blown tires and crosswind landings.
Once flying a plane the pilot is backed up by redundant aircraft systems – duplicates of things, just in case one fails. These can include separate primary and backup flight instruments, multiple hydraulic systems, and primary and emergency landing gear.
Safety checks and aircraft maintenance
Every pilot of a commercial airline completes a thorough pre-flight check, sometimes with the help of a maintenance crew. As well as checking that things like on-board instruments and wing flaps are working, he or she will also walk around the plane to see if things look like they should do. They check for things like fluid leaks, dents and dings, and that the pitot tubes (which measure airspeed) are not covered.
Maintenance staff check the aircraft daily, and then on a schedule laid out by the aircraft manufacturer. It’s a never ending cycle of inspections and services which is determined by things like flight hours, and how the aircraft is operated.
Deliberate passenger or aircrew action
Hijacking, or attempts by passengers to bring down a plane, have been a threat for decades, but thanks to improved airport and aircraft security this is less likely to happen than in the past. Fingers crossed. These days your hand luggage is checked on most flights, and sometimes your shoes too. You might even have it swabbed to detect for explosives. Then you walk through a through a metal detector, or a full body scanner.
A body scanner uses either non-ionizing electromagnetic radiation to detect objects in and around your body, or X-rays to do the same thing. There’s debate about the safety of both these methods. In Australia you can be banned from flying if you refuse to undertake a full body scan.
Following the 9/11 attacks cockpit doors on commercial aircraft are now locked. The cockpit can be accessed by a code, but in ‘locked’ mode the entry code is ignored for five minutes (which is repeatable). This could prevent unauthorised people entering the cockpit if they obtained the code from a flight attendant.
The Germanwings tragedy in 2015, when a suicidal co-pilot deliberately crashed his plane, killing all on board, heralded a rule requiring two people to be in the cockpit at all times. The rule is not mandatory, however, and in April this year Swiss International Air Lines announced it was doing away with it.
A bit of rocking and bumping is part of most people’s experience of a flight, but for some anxious passengers even light turbulence can feel like being trapped in a nightmare. Will the wings fall off? No. Will the plane plummet so far that it will hit the ground? No. Will an engine fall off? No, once more. Planes are designed to take an awful lot of punishment from turbulence. Light turbulence is normal. Moderate turbulence happens from time to time. Severe turbulence is very rare. Extreme turbulence can sometimes cause structural damage, but most pilots never experience it during their entire flying career.
If injuries do occur in powerful turbulence they are usually caused by flying or falling objects, or to people being flung about thanks to not having their seatbelt fastened. Pilots try to minimise the effects of turbulence by varying their speed, or avoiding the worst of it. They try to fly at an altitude reported as smooth by other pilots, and use radar to help detect the most turbulent areas of a storm.
A technology called LIDAR can detect Clear Air Turbulence, which gives no clues to its existence until you hit it. However, LIDAR is not installed on most aircraft as yet.
You can download an App here to measure turbulence on your flights.
Accidents caused by birds
You have probably heard of Captain “Sully” Sullenberger, the pilot of US Airways Airbus A320 that landed in New York’s Hudson River in 2009 after both engines failed. The incident was caused by a flock of Canada Geese that were sucked into the engine shortly after take off.
While this was a high drama at its best, a so-called ‘bird strike’ is a rarely dangerous, unless you are a bird of course. Aircraft are designed to withstand most bird strikes and pilots undergo rigorous training to deal with the situation. Incidents like the one Sully had to deal with are extremely rare. Although bird strikes happen in Australia, there have been no fatal civil aviation accidents due to bird strikes here.
But, how do you prevent it happening in the first place? Well, airports in New York now cull Canada Geese. While culling is sometimes necessary other methods are employed at airports, including firing flares, using distress calls and even using birds of prey.
Avoiding volcanic ash
When all four engines on a British Airways Boeing 747 shut down in 1982, the captain had no idea why. Without its engines the plane, which was flying from London to Auckland, had become a giant glider. It took several attempts and 15 minutes to get the engines started again, by which time it had glided from 37,000 feet to 12,000 feet. It took two days for experts to deduce that ash from an erupting volcano south east of Jakarta in Indonesia was the cause. The plane had flown through an ash cloud and the tiny particles had ground away the tips of the turbine blades.
Seven years later another Boeing 747, operated by KLM, suffered the same fate en route from Amsterdam to Tokyo. Again, an ash cloud – this time from a volcano in Alaska – caused all four engines to stop. It took many attempts to get them all started again.
So what safety measures were put in place? Well, in 1991 the aviation industry set up Volcanic Ash Advisory Centres so that meteorologists, volcanologists and the aviation industry could work together to help prevent future incidents. Today, airspace is temporarily closed if volcanic ash is detected above an upper limit. European flights can be badly affected, thanks to the Eyjafjallajokull volcano in Iceland that refuses to stop erupting.
Getting rid of ice
If you fly out of airports in Europe or America in winter you might be in for a treat. On snowy and very cold days your plane might pull up to a de-icing zone before take off, where a machine sprays the aircraft with an orange or white fluid. It’s done to prevent a build up of snow and ice on ‘critical areas’ of the plane, including the wings, horizontal stabilisers and the vertical stabiliser. These have to be free of snow and ice in order for a safe take-off.
Not only does ice and snow add to the airplane’s weight, it can also affect the movement of wing flaps and ailerons (panels near the tip of the wing that allows the pilot to roll the aircraft to the desired angle). It can also disrupt airflow, which reduces lift. Don’t do it and your plane might end up like an Air Boeing 737 which crashed into the icy Potomac River in Washington in 1982.Compare flights to Bali