I was reading that Jet Engines are among the most simplest type of engines there are. (Compared to plane or car or train etc). Therefore they are amonst the safest and are least likely to have things go wrong.
Now I being afraid to fly, was wondering if that is true or just the Airline industry trying to promote itself.
Jets are pretty simple when compared to an internal combustion engine like an automobile has.
HowStuffWorks has an excellent article on jet engines:
Jet engines are simple, mechanically speaking, though probably not as much as a Wankel, which is pretty much the epitome of internal combustion engine simplicity. The problem is, there’s a lot more stuff that can go wrong with an airplane than just having an engine conk out. In fact, on almost any modern commercial passenger aircraft, losing power on a single engine should not be catastrophic, except perhaps just before/after takeoff.
That said, commercial air travel is much, much safer than auto travel. Nearly everything remotely critical is redundant, and the maintenance standards are much higher than most people apply to their personal vehicles. And it takes a lot more time and money and effort to get a pilot’s license than a driver’s license. Speleophile speaks from personal experience here.
I have to add that since I got my pilot’s license, a lot of the fun went out of commercial air travel. Even though I’m not qualified to fly big jets, I’m no longer completely comfortable in any airplane unless I’m sitting in one of the front seats - preferably the left one! Any other doper pilots feel this way?
Well, a jet engine is basically a fan to suck air in, and another on the same shaft to turn the first, and something to squirt in fuel and ignite it in between, all stuffed into a tube. In the most simplified version, there’s just one moving part, the shaft with all the blades on it. And all it does is spin.
In contrast, in an internal combustion engine, such as a car engine, each cylinder has a piston moving up and down inside it, and two valves opening and closing to let fuel in and exhaust out, as well as some sort of linkage between the piston and the crankshaft. The valves and the sparkplug have to be timed to the movement of the piston, which is constantly being pushed up and down.
So yeah, it makes sense to say that the jet engine is simpler. It is somewhat misleading, as jet engines require incredibly tight tolerances, and are designed very precisely around complex fluid dynamic properties of the air and fuel involved. It really doesn’t take much of a failure to become catastrophic. Luckily, jet engines are built to be incredibly sturdy.
But the simplicity argument seems silly. A glass is simple. A car engine is not. However, the glass is more likely to break if you hit it with a hammer.
makes for an excellent beer cooler too:
Pull the stick up, the houses get smaller, push the stick down, the houses get bigger. Any questions?
I always found pulling back on the stick had more efect than pulling up, but then maybe I had it wrong. That whole house big house small thing goes out the window a little if you hold the stick back for too long.
While it is true that you can make an extremely simple ram jet or pulse jet, those devices bear only passing resemblance to the jet engines used in commercial aircraft. The engines used in aircraft are incredibly complex with turbines, movable nozzles, controls, etc.
I can’t give an off-hand count of moving parts or tolerances in comparing a commercial jet engine with a car engine, but I’d like to point out that the premise that a jet engine can be very simple does not necessarily lead to the conclusion that air travel is safer. The engines that are used are not simple, so the premise is irrelevant. It’s a fact that air travel is safer than highway travel, but that has very little to do with the engines used.
The fact that I can make a ramjet out of a pipe, a nozzle “machined” with a ball-peen hammer, and a can of fuel has no bearing on the airline industry any more than putting a firecracker under a tin can and calling it a piston affects the automotive industry.
OK it is true that a modern turbo fan engine is not necessarily simple in it’s systems and in the tolerances required in manufacturing, but the finished working engine is very simple. The beauty of them is that they have very few moving parts and all moving parts are rotational so there are no push/pull forces being imposed, and no sudden changes in velocity.
Also piston engines can have problems with shock cooling where retarding the throttle too quickly can cause the cylinders to cool too quickly and crack. Turbines on the other hand operate hot all the time and the power levers can be reduced from maximum power to flight idle as quickly as you like with no ill effects for the engine, this allows the most hamfisted pilots to operate them with ease 
The reliability of the turbine engine is such that some countries are allowing single engine turbine aircraft such as the Cessna Caravan to operate in a commercial passenger carrying capacity in Instrument Meteorological Conditions (IMC) ie, at night and/or in cloud.
Statistically (can’t provide a cite sorry, looking) you are safer in a single turbine engine aircraft than in a twin piston engine aircraft