Contents
What is the function of undercarriage in aircraft?
The main functions of landing gear, undercarriage to the primary structure of the aircraft, are to enable the aircraft for a taxi, safe landing and takeoff, and to support the aircraft in the rest of the ground operation.
How is the sound controlled in aircraft?
Passive control involves reducing the radiated noise by energy absorption, while the active method involves reducing the source strength or manipulating the acoustic field in the duct to get noise reduction. There are significant sources of noise in the fan or compressor, turbine and jet or exhaust jets.
What causes vibration in an aircraft?
Aerodynamics, mechanical malfunctions, and external factors such as atmospheric turbulence can cause airplane vibration. Other vibrations are detected by sight, sound, or feel and may depend on flight crew experience for analysis. Normal vibration. Each airplane has a unique signature of normal vibration.
What is airframe noise?
The noise from such aeroplanes during approach is largely dominated by airframe noise, i.e. the noise generated by the interaction of flow and those aircraft components deployed for landing, such as the landing gears and the wing high-lift devices.
What is wheel well in aircraft?
: a recessed compartment on the underside of an airplane for the reception of a wheel of a retractable landing gear.
What are the possible causes of propeller vibration?
Causes of vibration: propeller Vibration originating from the propeller is usually caused by a mass imbalance. A mass imbalance is when the center of gravity of the propeller is not in the same location as the center of rotation of the propeller.
What is engine vibration in aircraft?
Engine vibration is one of the important factors for aircraft to ensure flight safety. High Cycle fatigue with alternating stress caused by excessive vibration or resonance will accelerate parts damage, then make the structure failure, at last reduce the engine life.
How is the noise level of an airplane determined?
The FAA publishes certified noise levels in the advisory circular, Noise Levels for U.S Certificated and Foreign Aircraft. This advisory circular provides noise level data for aircraft certified under 14 CFR Part 36 and categorizes aircraft into their appropriate “stages.”
Why do we need noise certification for aircraft?
The noise certification ensures that the latest safe and airworthy noise reduction technology is incorporated into aircraft design and enables the reductions in noise experienced by communities. As noise reduction technology matures, the FAA works with the international community to determine if a stronger noise standard is needed.
How does the FAA regulate the noise level?
The FAA regulates the maximum noise level that an individual civil aircraft can emit through requiring aircraft to meet certain noise certification standards. These standards designate changes in maximum noise level requirements by “stage” designation.
When did the aviation noise and Capacity Act start?
In 1990, Congress passed the Aviation Noise and Capacity Act, which required that by the year 2000 all jet and large turboprop aircraft operated at civilian airports be Stage 3. All certified aircraft flying in the United States need to be Stage 3 or quieter.