时间:2011-04-05 11:37来源:蓝天飞行翻译 作者:航空 点击:次
To view this page ensure that Adobe Flash Player version 9.0.124 or greater is installed. Searching for an overdue aircraft in low light conditions causes lots of problems, and route planning should take account of this. Otherwise, it’s much the same as for day, though there are some aspects that demand some thought. Plot your route on the chart in the normal way, but navigate with electronic aids or features that are prominent at night, such as town lighting, lighted masts or chimneys, large stretches of water (big black holes), aerodromes, motorways, etc. One of the optical illusions you might come across is the apparent motion of a stationary object which isn't helped by rain on the windscreen. Apart from reducing visibility, it's a particular threat when fixing your position by a single light source. When little or no light is on the surface and a prominent one comes into view, it may seem that the light is above the horizon, which could lead you to pitch into a steep attitude in keeping with the resulting false horizon. Sometimes the effect is not much more than an uncomfortable climbing sensation even when you're straight and level, but an obscured windscreen could make objects appear lower than they really are. This will be more apparent with high intensity runway lighting, which may also give you the same effect that actors have on stage, where they can't see the audience through the bright lighting. The lack of normal contrast will also upset your altitude perception, making you feel further away and higher than you are. As a result, on a final approach you could find yourself too low and fast. The solution is to use every piece of sensory information you can, including landing lights and instruments. Problems will arise if several of the above factors affect you at once, especially if the landing point is sloping—this is where more frequent cross-referencing of altimeters is important. Helicopter landing sites must be checked out in daylight on the same day as they are to be used at night. Preflight checks should allow for night flying—carry a torch, and 2 landing lights are preferred. Permission to enter the rotor disc is given by flashing landing lights. |