737飞机震动空中处置

kiteland · 发表于 2013-10-30 19:41:09

Modern commercial jet airplanes provide smooth,comfortable travel that typically is free of vibration.Some types of vibration can be expected from time to time and are considered normal. However, isolated cases of abnormal vibration require prompt flight crew response and subsequent timely maintenance action.

Occasional airplane vibration during flight is not unusual. There are many causes of airplane vibration, including landing gear extension and retraction, extension of speed brakes, free play in movable surfaces, and systems malfunctions. Flight crews need to understand the causes and effects of airplane vibration so that they can take appropriate action to maintain flight safety and prevent excessive wear or airframe damage. In addition, flight crews can contribute to accurate reports of in-service events that will facilitate troubleshooting and maintenance activities.Understanding the possible sources of vibration and the information needed to isolate and correct vibration problems requires knowledge of the following:
1. Types of vibration and noise.
2. Causes of airplane vibration.
3. Detection of airplane vibration.
4. Flight crew response.
5. Maintenance troubleshooting.

1.TYPES OF VIBRATION AND NOISE
The following engineering definitions differentiate various forms and types of vibration and noise:
Vibration is oscillating, reciprocating,or any other periodic motion of a rigid or elastic body forced from a position or state of equilibrium. If the frequency and magnitude of vibration are constant,the vibration is said to be harmonic.When the frequency and magnitude vary with time, the vibration is random.

Buffet is a form of vibration usually caused by aerodynamic excitation. It usually is random and associated with separated airflow.For example, buffet may be felt during the extension of speed brakes or during air turbulence.
Flutter is an unstable condition in which unsteady aerodynamics excite the natural frequencies of the structure over which the air flows. The resulting vibrations can grow to a magnitude that causes the structure to fail.
Noise is a vibration that excites the air and can be heard. When the vibration is random, the noise is unmusical or confused. When the vibration is harmonic, the result is a tone like that produced by a musical instrument. It may sound like the whistling of a drain or a slight leak in a door.
英文版本，拓展知识，英文技术两不误。