飞机培训课件英文版：EX#20 ILLUSIONS CREATED BY DRIFT

1、PGI EXERCISE # 20 ILLUSIONS CREATED BY DRIFT,200612810807,Enabling Objectives,How to determine the wind direction. The illusions created by drift (headwind / tailwind / turning). Examples of some particularly hazardous situations & avoidance of them. Human Factors and Safety Considerations,Determini

2、ng Wind Direction,ATIS / Wx Forecast. Windsock. Water Waves. Grass / Crops / Trees Just like waves in motion. Flags/Smoke Aircraft Drift!,Enabling Objectives,How to determine the wind direction. The illusions created by drift (headwind / tailwind / turning). Examples of some particularly hazardous s

3、ituations & avoidance of them. Human Factors and Safety Considerations.,Definition,Illusion: “Perception of something objectively existing in such a way as to cause misinterpretation of its actual nature” Webster Dictionary,1997 Created by the difference between airspeed , groundspeed and drift. Whe

4、never any object is free from the ground, it is affected by the medium with which it is surrounded This means that a free object will move in whatever direction and speed that the medium moves,Drifting and Crabbing,Such an example is a power boat crossing a river If the river were still, the boat co

5、uld head directly to a Point on the opposite shore and travel on a straight course to that point without drifting,Why ?,An action taken on the basis of an illusion is a wrong and potentially dangerous action Recognize illusions React appropriately with illusions,Types of Illusions,Speed Illusions In

6、creased speed Decreased speed Turning Illusions slipping turn (A/C is turning too fast!) skidding turn (A/C is not turning fast enough),Speed Illusion,Headwind : Illusion That youve slowed down. Reality Youre flying at the same indicated airspeed. i.e. 100 KIAS, but your ground speed has slowed down

7、. Falling prey to the illusion Pitch nose down or increase power. Hazard Loss of altitude, ground obstacles. Increased fuel consumption,Speed Illusion,Tailwind : Illusion That youve speed up Reality Youre flying at the same indicated airspeed. i.e. 100 KIAS, but your ground speed has increased. Fall

8、ing prey to the illusion Pitch nose up or decrease power. Hazard Unrecognized loss of airspeed and potential stall.,Turning Illusion,Headwind to Tailwind: Illusion That youre slipping into the turn. Reality Youre flying at the same airspeed, in a coordinated turn. Falling prey to the illusion Is to

9、use inside rudder (causing a skidding condition) & opposite aileron to keep the turn going. Hazard Cross control situation, if uncorrected as airspeed decreases, will enter a stall/spin.,Turning Illusion,Tailwind to Headwind : Illusion That youre skidding away from the turn Reality Youre flying at t

10、he same airspeed, in a coordinated turn. Falling prey to the illusion Is to use outside rudder (causing a slipping condition) & opposite aileron to keep the turn going. Hazard Cross control situation, if uncorrected as airspeed decreases, will enter a stall/spin,Avoidance / Precautions,Downwind Leg

11、A strong wind will bring you to the halfway point on your downwind leg very quickly. To fix: may want to decrease a/s, not adviseable Fly into wind a little longer for more space and time for proper checks Adjust angle of bank in turn DO NOT USE EXTRA RUDDER PRESSURE to increase rate of turn Make yo

12、u skid/slip, increase drag, May choose a steeper AOB cautiously as required Do not try to correct for what appears to be the aircraft taking control. Must be aware, but as long as the A/C has ample wind flowing over the wings, it will fly.,Enabling Objectives,How to determine the wind direction. The

13、 illusions created by drift (headwind / tailwind / turning). Examples of some particularly hazardous situations & avoidance of them. Human Factors and Safety Considerations.,Examples of Illusions & Effects of Drift in Turns during High Wind Conditions,Figure 2-55C FTM,Other Hazardous Situations,Forc

14、ed Approach Precautionary Landing Cross Country trips Diversions Air Exercise,Examples of Illusions & Effects of Drift in Turns during High Wind Conditions,Figure 2-55A FTM,Examples of Illusions & Effects of Drift in Turns during High Wind Conditions,Figure 2-55B FTM,Enabling Objectives,How to deter

15、mine the wind direction. The illusions created by drift (headwind / tailwind / turning). Examples of some particularly hazardous situations & avoidance of them. Human Factors and Safety Considerations.,Safety Factors,Select a suitable area that is clear of obstacles, people and livestock. Maintain a

16、 safe altitude: 500 AGL in rural areas. 1000 AGL over built up areas. Lookout for other traffic, obstacles and hills. Max 15 - 30 Angle of Bank. No Steep Turns Flaps will increase visibility, and lower the stall speed. Maintain a safe airspeed,Human Factors,Importance of Awareness of possible illusions Awareness of Wind Directio