直升機教員手冊 Helicopter Instructor’s Handbook
時間：2014-11-10 08:35來源：FAA 作者：直升機翻譯 點擊：次
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To view this page ensure that Adobe Flash Player version 9.0.124 or greater is installed. Prior to takeoff, the instructor should discuss with the student how the wind velocity aloft are greater than those reported on the ground and may possibly shift. If the winds are known, the instructor can have the student calculate the amount of wind crab necessary to track the boundaries. This allows the student more insight to the use of crab angles to track courses. Not enough emphasis can be placed on always knowing which way the winds are coming from and how to be vigilant in seeking ground cues for hints of a wind change. S-Turn The S-turn is another training maneuver that requires a student to compensate for winds. [Figure 10-14] This maneuver requires turns to the left and right. Choose a road, a fence, or a railroad for a reference line. Regardless of what is used, it should be straight for a considerable distance and should extend as close to perpendicular to the wind as possible. An S-turn is a pattern of two half circles of equal size on opposite sides of a reference line. A standard radius for S-turns cannot be specified, since the radius depends on the airspeed of the helicopter, the velocity of the wind, and the initial bank chosen for entry. The maneuver should be performed at a constant altitude. While S-turns may be started at any point, it may be beneficial during early training to start the maneuver with the helicopter flying into the wind. Turns Around a Point This training maneuver requires the student to fly constant-radius turns around a preselected point on the ground, using a bank of approximately 30° while maintaining both a constant altitude and the same distance from the point throughout the maneuver. [Figure 10-15] The objective, as in other ground reference maneuvers, is to develop the ability to control the helicopter subconsciously while dividing attention between the flightpath, how the winds are affecting the turn, and ground references, while still watching for other air traffic in the vicinity. A reason to perform turns around a point, other than for proficiency, is high reconnaissance, photography, survey, and search and rescue. Great care should be exercised to remain clear of obstructions and other low-level traffic during ground reference maneuvering. The factors and principles of drift correction that are involved in S-turns are also applicable in this maneuver. As in other ground track maneuvers, a constant radius around a point requires the student constantly to change the angle of bank and make numerous control changes to compensate for the wind. The point selected for turns around a point should be prominent and easily distinguishable, yet small enough to present a precise reference. Common Student Difficulties Failure To Plan Properly Ensure the student plans properly for the ground reference maneuver to be flown, that should include checking the current and forecasted weather. Students often fail to take the wind into consideration when setting up to perform a maneuver. Point out that winds can be determined by observing ground cues, such as flags, ripples on a pond, or smoke. The student should be able to explain, prior to takeoff, how to maintain desired ground track while in flight. Coordination Remind the student that each control input causes something else to change. Remember, a beginning student may have difficulty not only in accomplishing the actions in the proper sequence, but also in compensating for control inputs. Talk the student through each maneuver to remove any doubt about what is to be accomplished, as well as how and when it is done. Division of Attention When performing a ground reference maneuver, students have a tendency to focus attention outside the helicopter, excluding cockpit or instrument checks or focus entirely on the interior checks to the exclusion of outside references. If the student focuses all attention outside the helicopter, a good way to refocus attention inside is to pose a question, such as “What is the helicopter’s altitude?” or “What is the airspeed?” If the student’s attention is focused inside the helicopter, have the student clear the helicopter or describe what he or she is using as an outside reference. Attitude Remember that the forward seating position and the excellent visibility in most helicopters may make it difficult for a student to visualize the attitude of the helicopter. It is important for the instructor to provide all the assistance possible to ensure the student can determine an attitude by some visual reference such as a cross-member or point on the wind screen. A water soluble marker can be used to place dots on the bubble representing the sight picture of the horizon at a given airspeed. Instructors usually develop different methods of teaching attitude references. Scan It is common for a student to concentrate on one factor to the exclusion of others. Due to poor scanning technique, the student may select a ground reference that fails to offer a suitable emergency landing area within gliding distance. Instructor Tips . A student will attempt to imitate instructor actions. Do not take shortcuts. Instill safety from the first day. Insist the student clear the helicopter in all directions prior to performing any maneuver. . Stay close to the controls at all times, but especially during the hover. Be prepared for both the expected and the unexpected. . Students transitioning to helicopters from airplanes may have “air sense” but, remember, they are still students. Students do the unexpected, especially students who are transitioning from airplanes to helicopters, and should be closely supervised. There are many negative transfers of training from airplanes to helicopters. In instances of stress, the airplane pilot can be expected to revert to “first learned” behaviors, which can have deadly consequences in helicopters. The differences should be well explained and briefed before each flight. |
