Why is it called the Jesus nut?
Origin. The term Jesus nut may have been coined by American soldiers in Vietnam; the Vietnam War was the first war to feature large numbers of soldiers riding in helicopters. The term may also have originated with the PBY Catalina, which had two Jesus bolts holding the wing into the fuselage.
Do all helicopters have a Jesus nut?
Now a lot of modern helicopters don’t have a Jesus nut. There are many other different methods of fixing the main rotor to the mast. However, the name is not going to disappear, because people are already using it for other crucial components of other mechanisms.
How strong is the Jesus nut?
Jesus nuts are simply very very big and strong. Some are really big. And here’s a video of the Jesus nut on a Russian MI-8 in flight. It’s holding 13,000 kg together or 14.33 US tons.
What is a mast nut?
Mast is the fruit of forest trees and shrubs, such as acorns and other nuts. The term derives from the Old English mæst, meaning the nuts of forest trees that have accumulated on the ground, especially those used historically for fattening domestic pigs, and as food resources for wildlife.
What does a swash plate do?
A swashplate is a device that is used to transmit the pilot’s commands from the non-rotating fuselage to the rotating rotor hub and blades. The fact that the rotor blades are rotating at a very high speed makes the swashplate mechanism’s task more challenging.
What is auto rotation on a helicopter?
Autorotation. In a helicopter, an autorotative descent is a power-off maneuver in which the engine is disengaged from the main rotor disk and the rotor blades are driven solely by the upward flow of air through the rotor. [Figure 11-1] In other words, the engine is no longer supplying power to the main rotor.
Why does a helicopter has a second rotor on its tail?
A helicopter tail rotor serves two essential functions. It provides a counteracting force to the helicopter’s main rotor; without the sideways thrust produced by the tail rotor, the torque generated by the main rotor would spin the helicopter’s body in the opposite direction.
Why do helicopter blades still appear?
The effect occurs due to the 60 cycle per second flickering of the light, which is normally too rapid for the eye to register. When the blade interval and frame interval are quite different from one another, the blades become blurred and the phenomenon disappears.
How does a helicopter not spin?
Helicopters do use their tail rotor to prevent themselves from spinning, but they use it to stop spinning in the opposite direction as the main rotor. This is called “torque reaction.” A torque is any force that causes something to spin.