What is angle of incidence helicopter?
Angle of incidence (AOI)—the angle between the chord line of a blade and rotor hub. It is usually referred to as blade pitch angle. For fixed airfoils, such as vertical fins or elevators, angle of incidence is the angle between the chord line of the airfoil and a selected reference plane of the helicopter.
How likely are you to survive a helicopter crash?
The probability of surviving the hypothetical 20-year career is 0.999982 to the 20,800th power (205220) or 0.68869%. The fatality rate is 10.6880. 312 or 31%.
What is the typical cause of death in a helicopter crash?
Results: A review of 84 autopsies revealed that blunt trauma was cited as the primary cause of death in 88.1% of these cases. The most commonly occurring bony injuries were fractures of the ribs (73.8%), skull (51.2%), facial bones (47.6%), tibia (34.5%), thorax (32.1%), and pelvis (31.0%).
What is the formula for angle of incidence?
It is given that the light ray is making 10° with the surface. Therefore, the angle of incidence is 90°-10°=80°. From the law of reflection, we know that the angle of incidence is equal to the angle of reflection.
How do you find the angle of incidence?
In the reflection of light, the angle of incidence is equal to the angle of reflection, measured from the normal (the line perpendicular to the point of impact).
What percentage of helicopter crashes are pilot error?
Today that statistic has reversed. Approximately 80 percent of airplane accidents are due to human error (pilots, air traffic controllers, mechanics, etc.) and 20 percent are due to machine (equipment) failures.
Are helicopter crashes more common than plane crashes?
According to the National Transportation Safety Board (NTSB), helicopters crash at a higher rate than airplanes. The crash rate for general aircraft is 7.28 crashes per 100,000 hours of flight time. That means helicopters have a 35 percent higher risk of crashing compared to airplanes.
What happens to the human body in a high speed plane crash?
Explosive Decompression Can Tear The Body Apart When an explosion tears a hole in the plane and the cabin’s pressure bubble bursts, however, something called “explosive decompression” takes place. In short, the pressure difference rushes at a person so fast, it tears their body apart.
Which angle is the angle of incidence?
The angle of incidence is the angle between this normal and the incident ray; the angle of reflection is the angle between this normal and the reflected ray. According to the law of reflection, the angle of incidence equals the angle of reflection.
How is the angle of attack on a helicopter determined?
Angle of Attack. It is defined as the angle between the airfoil chord and its direction of motion relative to the air (resultant relative wind). Several factors may cause rotor blade angle of attack to change. Some are controlled by the pilot and some occur automatically due to the rotor system design.
What is the difference between angle of attack and angle of incidence?
Angle of attack is one of the primary factors that determines amount of lift and drag produced by an airfoil. Angle of attack should not be confused with angle of incidence (blade pitch angle). Angle of incidence is the angle between the blade chord line and the plane of rotation of the rotor system.
How does takeoff and climb affect helicopter performance?
Takeoff and climb performance is greatly affected by wind. When taking off into a headwind, effective trans lational lift is achieved earlier, resulting in more lift and a steeper climb angle. When taking off with a tailwind, more distance is required to accelerate through translation lift.
When does translational lift occur in a helicopter?
Translational lift occurs any time there is relative airflow over the rotor disk. This occurs whether the relative airflow is caused by helicopter movement or by the wind. Assuming a headwind, as wind speed increases, translational lift increases, resulting in less power required to hover. The wind direction is also an important consideration.