A helicopter with a tail rotor is safer or not?

Question

A helicopter with twin main rotors on top such as KA50 were design with a system that will replace the traditional functions of a a tail rotor which could halt due to system malfunctions. Why many helicopter manufactures still went on with the tail rotor eventhough they knew the hazards very well?Any ideas boys and gals...

Answer 1

You've got some good answers there, and here are some of my comments:

1. Helicopters equipped with tail rotors are by far the most common, efficient, and proven design around today. In a hover in a calm wind, a conventional tail rotor uses about 18% of total engine power produced.

2. Helicopter designs without tail rotors include 2 rotor designs (such as Kamov, K-Max, Boeing BV234), NOTAR (MD design operates mainly by Kawanda effect and low pressure air nozzle, NOT by a second engine as suggested above), and tip jets (experimental only). A tail rotor-less design is more efficient becuase there is no pwer "robbed" from the main rotor, but the design is incredibly complex.

Certainly a helicopter without a tail rotor is safer in theory, but they have mechanical design challenges and performance limitations. As a helicopter pilot, my biggest worry is for somebody to walk into the tail rotor as they are pretty well invisible. The pilot has to operate the helicopter in accordance with its limitations and therefore I would say that neither design is safer than the other. And as already pointed out by another response, the tailrotor-less helicopters are also prone to mechanical failures - every helicopter needs an anti-torque device to counter Newton's third law - for every action there is an opposite and equal reaction. A helicopter literally has thousands of moving parts - tailrotor or not.

I think the MD NOTAR system used on the 520, 530, 600, and 900 helicopters is brilliant and probably the best of the systems, but they are twitchy at high speed. Also its too bad all those MD designs have such a cramped cockpit which limits their appeal to a lot of customers. They are quieter and in theory eliminate tail rotor strikes, but give me a real tail rotor in difficult cross wind conditions any day.

Answer 2

There have been precious few "advances" in aircraft technology which haven't come with costs. When those advances come, they are almost universally adopted. (You'll notice that nobody uses rotary engines or wire-braced structures, and just about everyone has seat belts, engine starters, and flapping hinges.)

It is fair to say that designs such as the Kamov avoid the tail rotor, but it's not fair to complain that the tail rotor is a problem because it is subject to "malfunctions." Having a second main rotor requires another gearbox takeoff, another drive shaft, another set of pitch-control hardware, and so forth. These are just as likely to fail if attached to a second main rotor as they would be if attached to a tail rotor. To be fair, every dynamic system of the helicopter could break.

The greatest danger with the tail rotor is tail rotor strike, as has been pointed out. But, this is not a flaw in the helicopter; rather it is pilot error. There's only so much a designer can do to anticipate and counter the pilot's possible mistakes.

Answer 3

The mechanical problems of the twin rotor helicopters are well documented. You have nearly twice the moving parts as a tail rotor equipped helicopter, plus the second rotor requires a huge amount of the available power. I have been flying in helicopters for years and the only crash I have been in involved a dual rotor CH 47 with failure to one of the rotor control systems. Fortunately we were on final approach and were able to bet the bird down safely. The best design so far is NOTARS, the no tail rotor ducted fan system. As far as lift capacity, try and out do the Sikorsky Sky crane or CH53. Both are single rotor heavy lift machines.

Answer 4

Helicopter are unsafe to look at ,on paper they can't fly but they do, the tail rotor as always been a concern to pilots cause they cannot see it and when hovering by tree top';s often they hit the trees,(in Vietnam many choppers went down from this as well) so there is a chopper called No Tar
stands for no tail rotor uses a second jet motor and directs the air to stabilize the aircraft has been around 12 or so years nothing new, The Nascar Driver The Late Great Davey Allison Died In a helicopter, landing is hello at a race track and the tail rotor hit the fence it was to close and flipped the aircraft on his side he died from head trauma, great loss to Bobby Allison (father)and the Nascar racing community

Answer 5

The tail rotor is an anti torque rotor. Although the KA50 had two main rotors. They rotated in opposite directions eliminating the need for a tail rotor. They just traded off one for the other.

Answer 6

I wish your question was better stated.
I personally like the tail rotor, I beleve it has a little more authority, but it does take power away from the main rotor.
The twin rotor is probebly a little more efficent when it comes to power useage but it has to be a little higher off the ground and the blades are closer to peoples heads.

Answer 7

As an aside, the main purpose of the tail rotor on a helicopter is pilot cooling - watch him (or her) start to sweat if it quits working.

Answer 8

it is safer to have a tail rotor on a helicopter

Answer 9

Check the aerodynamics of the twin main rotor configuration/concept ...explains it all.

"Risk vs. benefits"

Answer 10

Simply 'cause:
Turning two set of blades takes twice as much power than just one. So putting just one it has twice as more torque/shp (shaft horse power). Besides, it is more complicated= more $$$ and space.
It doesn't take much (power) away from the engine(s)to turn the tailrotor(s) in comparison to the extra main one.