Turbulence will not break up a plane in flight! Well, that is pretty much true. There was 1 recorded case of a BOAC 707 breaking up in turbuulence (+9,-4G) over Mt. Fuji Japan in 1960 but on one knows if broke up due to the turbulence or from an overspeed after a severe turbulence induced loss of control. Weather forcasting has come a long way in 53 years and no modern pilot has an excuse for getting near that kind of shearing force today.
Basically, there are only 4 things that can destroy a modern plane in flight; a bomb/missile (terrorism), a catostrophic maintenance / mechanical failure, a midair collision or a bad pilot.
The safety record of modern airliners is a partly testament to advances in security. This goes from intelligence agencies exposing plots to TSA finding guns. I know none of us have a love affair with TSA but they do catch some stuff we don't want on planes (they find about 2 guns a day nationwide). I am sure they miss plenty of stuff but it is better than nothing. There has also been a change in the way passengers act/react to threats. Try to hijack a plane today and you will likely get the crap beat out of you by the other passengers. Old school 'hijackers for ransom' were put out of business on 9/11 and no terrosist plots have been successful since then in the USA.
13% of accident are mechanical but there hasn't been a major fatal once since Alaska's in 2000. (the AA crash of an A-300 was deemed pilot error and even the Alaska crash was compounded by crew actions of running both electric trims together).
Improved ATC and traffic collision advances (TCAS 'Traffic Collision Avoidance System) and pilot training have greatly reduced the already miniscule threat from a mid air collision. 1986 was the last major fatal mid air in the USA.
Improved pilot training to include Windshear recovery, GRD PROX EGPWS terrain escape manuevers, unusual attitude recovery, wake turbulence seperation/recovery, flight in rarified air, turbulence avoidance and jet upset recovery, GPS/RNAV navigation (which has all but replaced the VOR systems in the airlines), glass cockpits with more info for pilots and gobs of other stuff. The last fatal crash in the USA was a Colgan Air commuter in 2009 due to pilot fatigue, poor training and icing conditions.
This is the case despite the skies becomeing even more jam-packed thanks to something called RVSM.
RVSM airspace (reduces the Required Vertical Seperation Minumum above 28,000 feet from 2,000 feet to 1,000 feet) has opened up a lot of airspace and also increeased safety by tightening requirements for planes flying at FL280 and above (FL-flight level. It is the altitude adjusted to standard barometric pressure of 29.92). Airplanes use local altimeter settings in barometric pressure (which changes with the weather) to insure all pilots are at the correct height. If the outside pressure 29.80 inches of mercury then pilots dial that into a little window in their altimeters (called a Kolsman window). It is like synchronizing watches. Now all airplanes in the local area have identical altimeter read outs (especially important in instrument flying).
Above 18,000 feet planes go to fast to keep up with local settings so when you hit 18,000 feet you dial in 29.92 (standard) into the Kolsman window and everybody is synched up. When you have jets with 1200 mile per hour closure rates and only 1,000 feet vertically between them, you need everyone working form the same playbook. When I am at FL350 and another jet passes overhead going the other way at FL360 (which happens many times per trip), trust me, you want to be sure our altimeters are in synch. BTW, altimeters are allowed about 100 feet of slop at high altitude so we could be only 800 feet apart and still be in compliance. Cheery thought eh?! (show less)
