Why are helicopters prone to failure?
In: Engineering
Helicopters aren’t really more dangerous than other aircraft, but what I think you’re talking about here is that fact that when something goes wrong on a helicopter, it’s game over, there’s usually no way to somehow save the aircraft or control it.
Airplanes have wings, and these wings work even when the engines don’t. The wings will work when pretty much anything else has failed, because they’re fixed. This means that when an engine fails on an airliner, it can glide an astounding distance, or when the aircraft is somehow structurally compromised it still has a chance to glide and land. With helicopters, everything kinda has to work all the time. If the rotors fail, you’re pretty much done for, if the tail breaks, you’re done for, and so on. This means that there usually isn’t much of a failsafe for when shit hits the fan.
You can kind of compare it to sailing boats and engine-driven boats. If the engine fails on a motorboat, there’s not really a plan B, you just have to wait for help or paddle or something. If the engine fails on a sailing boat, the engine is gone which is a problem but the sails still work, so that means that the boat can still sail.
This is changing though. Helicopter manufacturers are taking advantage of the helicopter’s compactness and adding things like parachutes for when the main rotor fails.
They aren’t more than any other machine. However, when their drivetrain fails for whatever reason, it does have a higher tendency to be catastrophic. When an airplane loses both engines, they can still steer and glide to safety; not ideal, but planes are made to fail in such a way that they can still glide. Helicopters don’t really have that because their propulsion /is/ what keeps them airborne. There are some techniques that can try to slow the fall, but ultimately, without power, a helicopter is going to fall quite quickly.
Contrary to what some others are saying, helicopters can [autorotate](https://en.wikipedia.org/wiki/Autorotation) and glide down to a landing on failure. However, they need suitable airspeed and altitude for it. If they are, as they often may be when things go wrong, near the ground or obstacles, there’s just not enough time and room to recover.
>Helicopters are typically used in dangerous situations where airplanes are unable to fly such as taking crews to and from ocean-based oil rigs, hovering in precarious rescue situations and flying low near obstacles like electrical wires and buildings. All of these situations put helicopters, their passengers and people on the ground at risk. This is why helicopter pilots are required to be very well-trained as they often encounter extremely dangerous situations.
Crashes are often listed as pilot error, but helicopters are hard to control in the first place and in the conditions they often operate, the pilot may only have a couple of seconds to regain control, find a safe spot to land, and make an emergency landing, if that’s even possible.
As for needing more maintenance – there are just a lot of moving parts. Rotors don’t just spin, they adjust pitch and angle and so on. And there’s not much capacity for redundancy, so there are a lot of potential single points of failure. If something goes wrong on a 4 engine jet, it can still fly ok. If something goes wrong on a one-rotor, one-gearbox helicopter, it’s going down.
That said, they’re not particularly prone to failure. It’s just that when they do fail, the odds of a safe landing are relatively low.
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