Ive watch every mayday episode and tons of crashes are caused by like a simple screw being put back wrong after maintenance, how the hell do all these planes get good enough inspections done even fly several hours without failing and falling out of the sky?
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Redundancies, double- and triple-checks. Most plane-related disasters are generally a culmination of multiple things that have gone wrong, any of which, if done correctly, would’ve prevented the accident. Good maintenance and good pilot training and procedure can make planes extremely safe and reliable. Most systems on a modern aircraft have at least one or two backups. Properly trained pilots know how to diagnose and troubleshoot problems in the air; if one gauge is giving a suspicious readout, they know how to interpret the other gauges to determine what the true situation is.
> To my understanding, there are millions of wires and pieces that all have to be working perfectly to keep a plane in the air
This is incorrect because aircraft have redundancy on critical systems. They don’t have to be perfect to fly, in fact they’re even allowed to take off in some situations despite known existing faults. That’s not to say that a single screw missing can’t eventually cause a crash in very rare circumstances.
In short, aircraft are designed, to the extent possible and economical, to keep flying and save lives even in the event of a fault.
I’ll add to the other answers this: Many many years of testing and refinement.
When a problem happens, especially a fatal accident, the FAA, NTSB, the manufacturer, airline and probably others do an extensive investigation. This adds to the body of knowledge about what can go wrong. If it’s at all possible, procedures or technology are put in place to prevent that particular problem in the future.
Airplane regulations are written in blood. Whenever there is an accident it gets investigated to find all the events leading up to the accident and then these are all fixed so that similar issues will not happen in the future. And even lots of mishaps that did not cause any accidents gets reported and investigated in a similar manner. One of the reasons why there are so many pieces and wires all over the airplane is that all of the critical systems have multiple redundant systems. So even two failures in separate systems should not cause anything bad to happen. But this means that you have a lot of systems installed on the aircraft all at once. Another concept is that everything is made as simple as possible. This means fewer failures. There are limits to how simple you can make systems on large modern airliners but they could have made them much simpler. So where you for example in a car have a few big computers controlling everything an airliner is mostly mechanical systems and independent smaller computers. But that also increase the parts count a lot.
On a commercial flight, several things are true:
– Your pilot has had well over 1000 hours of training.
– Your pilot is sober.
– Your pilot is well-rested (ideally, if the airline is following best practices).
– Your pilot has multiple other people, all under those same conditions, watching their work.
– The plane has been serviced regularly, which includes checks every 100 hours.
– There aren’t any other planes nearby – the approach, runway and flight path are all clear.
Compare this to a car:
– You can get a full license without a ton of supervised, formal training.
– You might be slightly, or highly inebriated.
– You might be tired.
– There’s probably not someone else watching too closely; if there is, they can’t access the controls.
– Your car might have been last serviced months ago, or longer.
– You are sharing the same little space with dozens of other drivers, all of whom share the same conditions.
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Also, when you see all those cases of “a screw was put back wrong and it caused catastrophic consequences”, you’re getting confirmation bias. You’re not seeing all the times that a screw was put back wrong but nothing happened and it was fixed at the next maintenance, or all the times that a screw was put back wrong but someone else fixed it.
>To my understanding, there are millions of wires and pieces that all have to be working perfectly to keep a plane in the air
That’s not true, but even if it was, so what? Why do you think planes should crash more? You haven’t articulated any reason why you think that other than complexity, which is not a reason. Lots of things are complex and don’t crash/fail/explode all the time. So why exactly do you think planes should crash more often than they do?
Due to the inventions of the Black Box Flight Recorder and the Cockpit Voice Recorder.
Planes used to crash a lot. Lots of people died (even Qantas used to have fatal crashes). So the two above mentioned devices were invented and eventually fitted to commercial aircraft.
The black box flight recorder records various bits of information about the the plane. How much power to the engines, what position are the flaps in. Etc, etc, etc, etc. The Cockpit Voice Recorder records conversations in the cockpit.
This means that when commercial planes crash and these two devices are located a lot of data can be examined regarding the crash and the time before it.
On top of this if possible the plane is recovered and if needed rebuilt as much as possible. Everything is gone over as much as possible for things that the recorders can’t record. Investigators can tell the difference between did a piece break due to impact or did it wear out over time. They can go through maintenance logs, etc.
All of this means that not only have planes been redesigned but flight practices have evolved (such as banning anything but immediate flight talk below certain altitudes) as have maintenance practices. After a crash airlines and aircraft manufacturers may be required to modify not only planes that are being built but also ones in service.
It is now rare that a single piece of a commercial airliner failing resulting in a crash. Almost all commercial airliner crashes are pilot error.
I have an Insane fear of flying based on losing someone super close to me in a plane crash when I was four. As a result, I’ve researched and done classes to try and get over it. The short answer is, most of it is computer regulated and as long as the computers don’t screw up- you should be fine. Also, anytime an accident happens, they learn so much that It’s basically impossible for the
Same thing to occur. The longer we fly, the safer it gets. That being said, new aircraft, and minor errors do happen and that’s what still terrifies me. One time a plane crashed because a mechanic replaced a window with bolts that were 1mm too short. 😯
One of the main factor is that all those wires you see, are built to aviation standards. For example: The aviation standard connectors and plugs are used in professional cameras and other devices because those are that much more reliable than any other on the market. Fireproof, waterproof, tolerant to oil, heat, corrosion. You can take a plug like that, dip it in salt, put it in a oven, the. Submerge it into saline water and it will come out completely damaged but still working.
Then every important thing is doubled or tripled, so if you lose one, you have another to keep fly the thing.
Last, there are statistics, example: you build the engine computer so it will never crash or fail. Still it will do something crazy every million hour. Perfect. Then you got the engine with two computers, and two complete sets of sensors. Now, once in a million hours, one of the two will fail, actually one every 500000 hours, because you doubled the chances to make it happen by doubling the equipment. Ok. Back on statistics, every 500k hours the channel A fails. You have one chance in 500k to lose the second channel and therefore lose that engine completely. Well done, if you land within an hour, you have 1/500k chances to lose the engine. If you lose that engine,which is 1/ 500k x 500k, so 1/250000 million!!!!!! (Yes, once every 250 billion hours) you can still glide the plane to a safe spot. You may be over a mountain and die, ok, that’s gonna happen 1% of your flight time. So one hour every 25 thousand billion hours you risk to die.
That’s how they are kept safe. And consider that 99% of the aircraft systems are not vital points. Except engine and flight controls, there’s not much that can make you crash. Not without a massive warning. You basically need to have multiple failures and be stubborn enough to not declare emergency and land, keep going for a while and deliberately fly into obstacles, to actually crash.
-I’m an aircraft mechanic.
Note:I have to fix a lot of broken stuff every day, in 20 years,I saw maybe 2-3 critical parts with damage. Everything else was no consequences, just repair it to go back to safety standards.
In the simplest possible terms: aircraft (and every single component used in their manufacture) are designed to a certain set of rigorous standards.
Those standards require that the chance of any type of failure happening must be below a certain threshold (this is proven by testing every part of the design both as an individual unit and after being integrated into the system)
The degree of testing required for any component or device to be used on an aircraft is huge. It is very difficult to understand without experiencing the industry yourself.
If the result of a component failing is an event that causes a hazard to the aircraft or occupants then it will have at least one redundancy.
If the total chance of any failure or combination of failures that may cause loss of life is above a certain threshold (Think 1 in a billion per flight hour, that’s not an exaggeration) then additional redundancy is required until the chance of dying in a fiery crash is below the acceptable level.
The chance of these failures is a known quantity and there are millions of very smart people (and also me apparently) who have been paid to prove that each tiny individual component (down to single lines of code) of this massive machine is reliable enough to meet the lofty standards set by commercial aviation.
Then more people are paid to critically review the work done (with extreme prejudice) to ensure it is correct.
The process of designing and maintaining commercial airliners is incredibly thorough. That’s why it’s the safest way to travel (per mile at least).
* assurances about safety are null and void when management overrides engineers in matters of safety.
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