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. Manual operation of a nongoverned throttle can be explained and demonstrated during instruction on the collective. A simple explanation that students may be able to relate to is comparing the manually controlled engine to a manual car transmission and a governed engine to an automatic transmission. Proper use of the throttle is an integral part of maintaining both engine and rotor rpm during flight. Explain the use of throttle friction in reducing the sensitivity of the throttle. While students who have experience riding motorcycles or other powered recreational type vehicles are familiar with the concept of a twist-grip throttle, instructors must guard against twisting the throttle in the wrong direction for a given application. Training on governor override or manual throttle operation should be explained, but a demonstration and practice should occur only after the student has mastered all the control inputs required to fly. Explain that revision to the manual mode of operation is an abnormal, or emergency, procedure and is almost exclusive to reciprocating powered helicopters. Few large turbine powered helicopters have a manual override function suitable for training. Stress to the student the importance of checking the throttle during the preflight. The throttle, whether governed or not, must have freedom of movement from stop to stop. There should be no binding or excessive stiffness in the operation of the throttle. Point out that throttle control friction must be decreased before checking the throttle. Special attention should be given to ensure that the throttle/ power lever is set in the “start” position prior to starting. This position varies between aircraft design and is explained in the Rotorcraft Flight Manual for the particular helicopter being flown. Improper throttle or power lever settings can lead to overspeed of a reciprocating engine due to the clutch, or engine temperature exceeding limits with turbine powered helicopters. Cyclic Pitch Control A student should understand that moving the cyclic control tilts the rotor system in the direction the cyclic is displaced whether it is fore or aft, or in a side to side motion thereby providing thrust in the direction the rotor is tilted. [Figure 4-4] This cyclic movement from the pilot’s right hand results in the aircraft moving in the direction the pilot desires as the cyclic is displaced. Any movement from the cyclic has a corresponding effect on the pitch of each blade either increased or decreased pitch as they move or cycle thru every rotation 360°. This enables the aircraft to move in the direction the pilot desires. Emphasis must be placed on keeping the cyclic free of obstructions. Students must understand the importance of ensuring the cyclic is free to move its full travel and to keep it clear of anything that could interfere with or limit its movement such as knee boards or passenger legs. Demonstrate the cyclic input required to hover. Initiate a takeoff and climb to a safe altitude. Demonstrate how the cyclic is used to maintain the pitch and bank attitude of the helicopter and maintain a constant airspeed during climbs, descents, and turns. Explain the use of the cyclic trim system to relieve cyclic pressures and reduce pilot fatigue. During the preflight inspection, demonstrate movement of the cyclic in all quadrants and allow the student to observe the inputs made to the swashplate and main rotor system. Antitorque Control Discuss the primary purpose of the antitorque system: to counteract the torque effect created by the rotation of the main rotor system. The antitorque system could consist of vectored thrust from the engine or be provided by a tail rotor. Explain that in either case, the function is the same. Most training helicopters will utilize a tail rotor for this purpose. [Figure 4-5] Antitorque pedals change the pitch of the tail rotor and provide the thrust required to counteract the torque effect. Discuss how the pedals are used to maintain coordinated flight during cruise flight, but are used for heading control during hovering flight. Operation of the antitorque pedals through the full range of travel allows the student to observe the pitch change in the tail rotor. Always remind the student of the safety hazards of pinching, moving parts and to keep well clear while the controls are being moved. Explain to the student the importance of keeping the antitorque pedals free of obstructions and having full range of movement. Emphasize that loose objects that fall during flight and are not retrieved could jam the pedals and reduce aircraft controllability. Demonstrate pedal inputs during a hover. [Figure 4-6] Climb to a safe altitude and allow the student to operate the pedals to maintain coordinated cruise flight. Demonstrate how the pedals are used during climbs, descents, and coordinated turns in cruise flight. Explain that when increasing collective pitch, antitorque requirements are greater; when reducing collective pitch, antitorque requirements are less. During this demonstration, the instructor maintains coordinated flight with the other controls. Practice Once the student has practiced with each of the controls individually, while still at a safe altitude, gradually turn over control of the aircraft one control at a time. Remember, STAY CLOSE to the flight controls. When the student has a basic understanding and demonstrates the ability to control the aircraft at altitude in cruise flight, use the same procedures to introduce aircraft control during hovering flight. Allowing a beginning student to fly down a runway or taxiway, or other set ground track. Making slower and lower approaches will almost naturally lead the student into the hovering mode, allowing a better understanding of control response while avoiding the overly early and frightening attempts at hovering flight. This technique allows them to learn the changes in the helicopter’s response to lower airspeeds and ground effects at their own pace. |
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