直升機(jī)教員手冊(cè) Helicopter Instructor’s Handbook
時(shí)間：2014-11-10 08:35來(lái)源：FAA 作者：直升機(jī)翻譯 點(diǎn)擊：次
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To view this page ensure that Adobe Flash Player version 9.0.124 or greater is installed. Approach Angle The student must understand the reason for utilizing a standard approach path. It is to establish the final approach leg at a distance and altitude that requires the same angle to the landing spot on each approach. In this manner, the student learns to visualize the correct approach angle, making it easier to learn the techniques for making corrections. If there is a visual approach slope indicator (VASI) of some type near, it is good to have the student look up the VASI’s glide slope angle and then fly to the VASI. It is often helpful for the instructor to fly while the student observes how the stated angle appears. Because VASI’s are often near 3°, about three times that angel (9°) can be a normal helicopter approach angle. The instructor will then announce when the VASI angle is doubled and finally begin the descent when triple the VASI angle. This allows the student to have a gauge or standard for the normal approach angle. Traffic With all the other factors requiring the student’s attention, it is very easy to relax vigilance for other aircraft. Before turning to base leg, the student should be required to check for approaching traffic and state whether the pattern is clear of conflicting traffic. Then on final approach, the area should be checked in all directions to make sure there are no other aircraft on, or about to turn onto, the final approach leg. Power Adjustments During the approach, the power setting is usually quite low. In a hover, it is quite high. Most beginning students wait until they are very close to the ground before adding power. This can easily lead to overcontrolling. This is usually done while transitioning through translational lift. The instructor should remind the student that, as power is added by increasing the collective, the cyclic must be used to ensure the extra power is all directed to replace the lift lost as translational lift is lost. This is done by adjusting the cyclic aft in most conditions. As this is happening, the student will also correct for yaw from the loss of translational thrust and place the helicopter in a slip to align the landing gear with the ground track. This habit is important when a landing to the surface begins. When power is added, the attitude must be changed to continue moving forward and down to the intended landing spot. Forward cycle may be needed because too much deceleration will excessively slow the rate of closure. While paying attention to airspeed and the height/velocity diagram, it may be necessary to slow the helicopter more than usual in the beginning phases of training so the student understands, and is comfortable with, the transition from the approach to the hover. Go-Around Before solo, a student must be taught the procedures and techniques used in a go-around. Encourage the student to use the go-around procedure as a safety precaution at any time he or she is uncomfortable with continuing the approach. Go-arounds should be taught early and often. Every student should know that go-arounds are good maneuvers for the best pilots. If in doubt, go-around! Students should learn to abort landings when the circumstances feel uncomfortable. Instructional Points A go-around is initiated by adding power to the climb power setting and accelerating to climb speed. When power is added, two common errors may occur: 1. With the initial power change, the rate of descent may stop, and the student may not add enough power to continue a climb (they level off). 2. When power is added, the nose of the helicopter begins to rise, giving the impression that the helicopter is climbing. This results in a loss of airspeed if no forward cyclic is added. If allowed to continue, the helicopter may begin to settle. When the decision to initiate a go-around is made, carry it out without hesitation. Common Student Difficulties Initiating the Go-Around Even experienced pilots may be hesitant to initiate a go-around, either from failure to recognize the need for one or as a matter of pride. Teach the student to recognize the need for a go-around early in the approach instead of waiting until the last moment. The safety of the aircraft and its occupants is the first consideration, and a go-around should be executed at the first indicationof an unsatisfactory approach or any unsafeconditions on the intended landing point. Also discuss with the student the difference in helicopter reactions (power requirements) while performing go-arounds above and below ETL. Coordination Many things must be accomplished simultaneously as a go-around is initiated. Collective is increased, rpm is adjusted as necessary, antitorque pedal corrections are made, and the attitude is adjusted to first accelerate to climb speed and then to maintain it. In the process, the student might overlook one or more of the required adjustments. It may help to practice the first few go-arounds at higher altitudes so the proximity to the ground is not a distracting factor. Normal and Crosswind Takeoff From a Hover The normal takeoff from a hover is the transition from hovering flight into a climb over a specified ground track. During the climb, airspeed and altitude should be such that the crosshatched or shaded areas of the height/velocity diagram are avoided. Other types of takeoff may be performed; however, the student needs to learn early how and why he or she is performing a specific takeoff. The pilot should be making a risk assessment to determine which type of takeoff is the safest. Instructional Points Discuss with the student during the preflight, what control inputs are required during hovering flight and takeoffs. There is more to a normal takeoff than just adding forward cyclic. Bring the helicopter to a hover and make a performance check, which includes power, balance, and flight controls. The power check should include an evaluation of the amount of excess power available. The balance condition of the helicopter is indicated by the position of the cyclic when maintaining a stationary hover. Wind may necessitate some cyclic deflection, but there should not be an extreme deviation from neutral. Flight controls must move freely, and a helicopter should respond normally. |
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