机务专业英语简答题

❶简述空气动力There are four aerodynamic forces that act on an airplane in fight; these are lift, drag, thrust and gravity。

关系：Lift opposes weight and thrust opposes drag. lift equals weight and thrust equals drag概念：Gravity constantly pulls the airplane toward earth. Thrust is any force acting in the same direction as the airplane's flight path. Lift acts perpendicular to both the flight path and the wing's span. Drag is any force acting parallel to the flight path but in opposite direction. So for airplanes to fly, the thrust must be greater than the drag and the lift must be greater than the gravity.方向：drag is the backward force; lift is the upward force; gravity is the downward force; thrust is the forward force.❷飞机的控制面Airplane Control SurfacesFor an airplane to be controllable ,control surfaces are necessary. The four main control surfaces are ailerons, elevator, rudder and flaps.Ailerons Located on the trailing edge of the wing, towards the wing tips, the ailerons control the airplane's roll. This movement causes a slightdecrease in lift on the wingtip with the upward moving aileron, while the opposite wingtip experiences a slight increase in lift.The rudde r is located on the back edge of the vertical stabilizer. The air running over the fin now pushes harder against the left side of the rudder, forcing the nose of the airplane to yaw round to the left.The elevators are located on the tailplane, or horizontal stabilizer. Moving the elevator up will cause the airplane to pitch its nose up and climb, while moving them down will cause the airplane to pitch the nose down and dive.Flaps are located on the tailing edge of each wing, between the fuselage and the ailerons, and extend outward and downward from the wing when put into use. generate more drag which slows the airplane down much faster than just reducing throttle power.❸影响ATC 的因素？What problem can influence ATC ?Traffic:problems begin when airlines schedule more arrivals into an airport than can be physically handled ,or when delays elsewhere cause groups of aircraft that would otherwise be separated in time to arrive simultaneously.Weather:Rain or ice and snow on the runway cause landing aircraft to take longer to slow and exit.Fog also requires a decrease in the landing rate.Aircraft will deviate around storms .❹影响飞机安全的因素？What are the relating factors on flight safety ?①Design and ManufactureDuring the design and manufacture of an aircraft great attention is paid to detailed aspects of the design, as well as overall considerations.②Preflight CheckBefore an aircraft departs on a flight it is checked by the ground and flight crews .③Air Traffic ControlWhile the aircraft is in the air or maneuvering on the ground , air traffic control seeks to ensure that it is safely separated from adjacent aircraft.④Technological DevelopmentsTechnological developments are being proposed to improve the crashworthiness of aircraft.⑤Human ErrorHuman error is a factor in many accidents and it is now receiving considerable emphasis.❺黑匣子What is black box ? what is the function of black box ?Flight data recorders(FDRs) and cockpit voice recorders (CVRs) , commonly known as black boxes , are devices used to investigate the cause of an aviation accident .It is Orange-painted and crash-proofed,FDRs and CVRs preserve vital information , such as the airplane’s speed and altitude, and conversations between the pilot, copilot, and air traffic controllers.功能：When an aviation accident occurs, officials usually begin their investigation by attempting to locate black boxes and using the information collected by the FDR to create a computer animation of the accident. Combined with the conversation and noises recorded by the CVR , this animation often assists investigators in reconstructing the events that led to the accident.❻.What weather can affect flight ?1. )Poor visibility: The see and be seen basis of collision avoidance is not possibility in visibility conditions below the VMC minima .And airplan control cannot be properly maintained when a significant part of the horizon is obscured.2.)Thunderstorms: thunderstorms produce meteorological hazard to flying-turbulence ,hail ,icing ,lighting, gusts ,and squalls3.)Turbulence :Severe turbulence causes large ,abrupt changes in altitude and attitude, large variation in indicated airspeed ,and momentary loss of control4.)Windshear and wind Gradient: Windshear and wind gradient is difference in wind speed and direction over a relatively short distance in the atmosphere。