直升机教员手册 Helicopter Instructor’s Handbook
时间：2014-11-10 08:35来源：FAA 作者：直升机翻译 点击：次
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To view this page ensure that Adobe Flash Player version 9.0.124 or greater is installed. After reaching a hover, take care to avoid hitting the ground with the tail rotor. If an upslope wind exists, execute a crosswind takeoff and then make a turn into the wind after clearing the ground with the tail rotor. Common Student Difficulties Eager to get the helicopter back into a level attitude, the student may use excessive cyclic into the slope or apply up collective too rapidly. Emphasize that smoothness is essential to a safe, comfortable takeoff. Cyclic should be positioned into the slope before the collective is raised. The rotor disk should be checked visually to see that it is level with the natural horizon or inclined slightly toward the slope. Increasing the collective slowly enables the pilot to remove the lateral cyclic input so the helicopter is level when the upslope skid leaves the ground. Antitorque pedal input is gradually increased as the cyclic is raised, preventing a turning tendency. Caution the student to stabilize the hover before beginning the climb. Confined Area Operations A confined area is an area in which the flight of the helicopter is limited in some direction by terrain or the presence of obstructions. For example, a clearing in the woods, a city street, road, parking lot, or a building roof or medical landing pad can be regarded as a confined area. [Figure 11-9] Generally, takeoffs and landings should be made into the wind to obtain maximum airspeed with minimum groundspeed. This is a comprehensive exercise that may require more than one session of preparatory ground instruction. Another critical aspect of confined area operations involves the student’s ability to estimate the size of the confined area as it relates to the helicopter. Tips on how to visualize the placement of the helicopter in the confined area are very helpful. A good exercise for obstruction judgment is to hold a broom around the edges of the rotor disk, not just the front. WIND Figure 11-9.If the wind velocity is 10 knots or greater, expect updrafts on the windward side and downdrafts on the lee side of obstacles. Plan the approach with these factors in mind, but be ready to alter plans if the wind speed or direction changes. Blade strikes usually occur on the side of the helicopter. Ask the student if the blades would miss the broom to help build judgment. As training progresses, the instructor should point out wires and dead tree limbs hiding in plain sight, invisible under most circumstances when airborne. If there is a shortage of suitable confined areas in the local training area, consider planning cross-country navigation exercises to locations that may have more suitable training areas. When introduced to this exercise, most students require more than one orbit of the area to obtain all the information they require. Encourage cutting down this number as proficiency increases, until experience reduces it to a practical minimum. Instructional Points Approach and Landing There are several things to consider when operating in confined areas. One of the most important is maintaining a clearance between the rotors and obstacles forming the confined area. The tail rotor deserves special consideration because in some helicopters it cannot always be seen from the cabin. This not only applies while making the approach, but while hovering as well. Exercises in distance and size estimation can assist the student in creating a reference base for the dimensions needed to land in a confined area. Simple cues such as the known dimensions of a football field (50 × 120 yards) can give the student a large-scale reference. An automobile parking space (9 × 18 feet) can help the student judge smaller distances as they correlate to the footprint of the helicopter. Ask the student for the size of the confined area while he or she is conducting the high reconnaissance. This provides information about the student’s ability to capture this information. Keep in mind that wires are especially difficult to see, but their supporting devices, such as poles or towers, serve as an indication of their presence and approximate height. If any wind is present, expect some turbulence. Consider the availability of forced landing areas during the planned approach. Think about the possibility of flying from one alternate landing area to another throughout the approach, while avoiding unfavorable areas. Always leave a way out in case the landing cannot be completed or a go-around is necessary. A high reconnaissance should be completed before initiating a confined area approach. Start the approach phase using the wind to the best possible advantage. Keep in mind areas suitable for a forced landing. It may be necessary to choose between an approach that is crosswind but over an open area and one directly into the wind but over heavily wooded or extremely rough terrain where a safe forced landing would be impossible. If these conditions exist, consider the possibility of making the initial phase of the approach crosswind of the open area and then turning into the wind for the final portion of the approach. Always operate the helicopter as close to its normal capabilities as possible considering the situation at hand. In all confined area operations, with the exception of the pinnacle operation, the angle of descent should be no steeper than necessary to clear any barrier in the approach path and still land on the selected spot. Always make the landing to a specific point and not to some general area. This point should be located well forward, away from the approach end of the area. The more confined the area, the more essential it is that the helicopter be landed precisely at a definite point. Keep this point in sight during the entire final approach. Use forward and lateral cues near the termination point to assist in maintaining the desired glidepath. When flying a helicopter in confined areas, always consider the tail rotor. A safe angle of descent over barriers must be established to ensure tail rotor clearance of all obstacles. After coming to a hover, take care to avoid turning the tail into obstructions. |
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