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. 8. The student cannot be initially allowed to lower the collective after touchdown. Once the helicopter is completely down and no longer subject to bouncing and flexing, some helicopter RFMs allow a slight decrease in collective to aid stopping and to decrease low rpm blade flexing. For a detailed description and illustration of autorotation, refer to chapter 11 of the Helicopter Flying Handbook (FAA- 8083-21, as revised). Instructor Tips . Start the presentation of new material at the student’s level of understanding. [Figure 3-20] . Check out Internet sites such as the National Aeronautics and Space Administration (NASA) Beginner’s Guide to Aeronautics (www.lerc.nasa. gov/WWW/K-12/airplane/index.html) for graphics and simulations for use in explaining aeronautics. Chapter Summary This chapter reviewed essential points to be taught during aerodynamics instruction. It provided the instructor with additional material that can be used in explaining aerodynamic principles, as well as examples to enhance the learning process. revolutions per minute (rpm). If the helicopter powerplant has a governor, then the pilot must ensure that power stays within limitations. If the cyclic is moved, then the collective must be moved to maintain altitude because lift has now been redirected into thrust for travel. Anytime the collective is moved, the pedals must be adjusted for heading or trim. Training for this control coordination can be accomplished by using a simulator or a helicopter. Use of a simulator for this instruction reduces student stress levels and may enhance learning. If a simulator is not available and instruction takes place in a helicopter, the instructor should ensure the student understands the location and function of each control. It is also imperative that the instructor stay close to the flight controls during all phases of flight. Flying a helicopter is inherently demanding due to all of the moving parts and the controls available to the student and the instructor alike. It is paramount that the instructor be able to manipulate the controls to keep the aircraft in a safe flight profile at altitude and as the student is moved to flight modes requiring increasingly more vigilance, such as a hover in proximity to the ground, other aircraft, and personnel. As the instructor, develop a safety-focused teaching style while being inconspicuous to the student. This is called the “instructor pilot ready position.” It is recommended that the instructor be very close to the controls so the student cannot move the controls too far or the controls will hit the instructors waiting hand or foot. A good instructor forms a boundary area around the controls in which the student can operate the controls without interference from the instructor’s fingers and feet. This boundary formation should ensure the helicopter stays within the instructor’s personal limits, yet allow the student to develop a control touch without interference. The instructor should always judge the situation by the flight status and condition of the helicopter, not by what the student is doing. It is what the helicopter is doing that is important. Whether using a simulator or helicopter, beginning the flight instruction at altitude is a good way to allow the student to manipulate all of the controls at one time and with a larger margin of error than beginning the flight instruction at a hover. As the student’s proficiency increases and the flight control inputs become smaller, the student can then be allowed to fly lower and slower, ultimately terminating an approach to a hover. A less preferred but widely used technique is to let the student operate one control at a time while the instructor operates the others so the student can get the feel of a control and its function in flight. Always emphasize making smooth, coordinated control inputs. Collective Pitch Control Explain to the student that the collective changes the pitch of the main rotor blades (angle of incidence) and, as a result of that pitch angle change, is used to increase or decrease the blade angle of attack (AOA). This is accomplished through a series of mechanical linkages that changes the angle of incidence of all blades simultaneously, or collectively. [Figure 4-2] Demonstrate on a static helicopter how pulling up on the collective increases the pitch of the rotor blades while lowering the collective decreases the pitch. Explain how the collective is used to increase both lift and thrust by changing the lift vector. Stress to the student that the collective must be kept free of obstructions at all times. The instructor must ensure the student understands the importance of ensuring the collective is free to move through its full range of travel and is kept clear of anything that could limit movement, such as a thigh, map, cell phone, camera, or even an article of clothing. An instructor may demonstrate how to use the collective to initiate takeoff, climb, and descent. One technique for practicing the application of collective pitch occurs during flight. Climb to a safe altitude and allow the student to operate the collective to climb, descend, and maintain altitude during a turn. Explain the proper application and use of collective friction. Demonstrate how the collective is used to maintain a constant altitude during accelerations and decelerations. During this demonstration, the instructor initially maintains level flight with the other controls and gradually allows the student to have the others controls as proficiency is gained. Throttle Control A student must thoroughly understand the intricacies of the helicopter being flown. While some helicopters have a governor to control the engine revolutions per minute (rpm), or a correlator to increase/decrease throttle inputs automatically to an acceptable range that generally requires some pilot input, other models rely solely on the pilot’s manual input of twisting the throttle. [Figure 4-3] Even when rpm is controlled by a governor or fuel control system, emergency procedures require manual operation of the throttle to control engine and, ultimately, rotor rpm. |
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