The helicopter has really changed the way that many things are done since it was invented. Traditionally, the helicopter has a rotor or two up top and a tail rotor. The upside to the design is that it can take off and land vertically. The downside is that a rotorcraft isn't as fast as fixed wing aircraft. Eurocopter has announced that its X3 Hybrid combining rotors with propellers has hit a speed much higher than normal helicopters are capable of. The X3 hit speeds of 232 knots or 430 km/h in testing. This will be a fantastic aircraft for rescue mission where speed is critical.
The helicopter has really changed the way that many things are done since it was invented. Traditionally, the helicopter has a rotor or two up top and a tail rotor. The upside to the design is that it can take off and land vertically. The downside is that a rotorcraft isn't as fast as fixed wing aircraft. Eurocopter has announced that its X3 Hybrid combining rotors with propellers has hit a speed much higher than normal helicopters are capable of. The X3 hit speeds of 232 knots or 430 km/h in testing. This will be a fantastic aircraft for rescue mission where speed is critical.
Most helicopters use turbo jets to propel their rotors.
This, although it might look similar, is a completely different concept
While traveling aa given speed "S", one of the blade edges will travel at S PLUS RS(the rotational speed of the blades), while the other will be at S MINUS RS (the blade is traveling in the opposite sense, so speeds are subtracted).
When one half of your blade suddenly enter supersonic speed, while the other half is much slower, 3 troubles ensues:
- The lift of an heli blade is near zero at mach 1
- The lift of the two blades is strongly asymmetrical
- Shockwaves will tear the blade apart in no time.
That's why the maximum theoretical speed for an helicopter is around 500 km/h. That said, the speed record for an heli is around 400 km/h, so there is a small margin for improvement.