Xu Wei reacted subconsciously and grabbed the instructor's right hand, which made the instructor who was concentrating on stalling out of a cold sweat.

Fortunately, the instructor is experienced and not as reckless as Xu Wei, and there was a situation where he accidentally moved the accelerator due to fright. The change of power_on_stall is relatively simple, press down on the nose and reduce the angle of attack of the aircraft. The instructor leveled the plane and set the throttle in cruise gear, before patting Xu Wei's shoulder with a smile and saying, "Man! easy，easy！ It means to let Xu Wei relax and not be nervous.

Xu Wei's face was hot, and he couldn't wait to find a crack to get into. A big man is scared like this, it is really a shame to be thrown home, more precisely, a shame and a foreign country. The instructor looked at Xu Wei, who was blushing, smiled, and controlled the plane to carefully avoid the cloud area in front of him, the cloud is not thick, and it is almost a few threads, but this flight did not make an instrument flight plan in advance, it is not allowed to pass through the clouds, and at the same time, the clouds are more prone to icing, the Cessna 152 does not have the ability to de-icing, although the temperature at 3,000 feet will not be as low as freezing under normal conditions, it is always good to be careful, and the flight is always safety first.

Bypassing the cloud area, what appeared in front of Xu Wei was a cloudless blue sky, which was simply a perfect flying environment.

“ok，power_off_stall!go，go，go!“ The instructors were eager and motivated. This time, Xu Wei learned to be obedient and quickly stopped it.

power_off_stall is to simulate the stall situation in the landing phase, and the procedure for changing out the steps is more complicated than power_on_stall, which has been learned in the theory class for a long time, as for the specific complex method, Xu Wei does not know, only knows that the flaps need to be adjusted when changing out. In case you are doing a stall and you are so scared that you do something stupid and prevent the instructor from changing out, then everything is really over.

The instructor was stunned by Xu Wei's several consecutive "no", and when he contacted Xu Wei's previous performance, the instructor suddenly realized, and deliberately blinked his eyes a few times, saying that I understand! A few black lines appeared on Xu Wei's forehead, and the instructor's meaningful eyes made him feel a little unhappy in his heart.

Since Xu Wei didn't want to stall anymore, the instructor was ready to go back to Athens and set the GPS destination to Athens, as long as he followed the GPS guidance. When it comes to navigation equipment, GPS, VOR (Very High Frequency Omnidirectional Beacon) are commonly used in modern aircraft. NDB (non-directional beacon) has basically been eliminated in the United States, and non-precision approaches are basically GPS approaches during the instrument grade exam, and NDB approaches are not done.

At a distance of more than ten nautical miles from Athens, it begins to require a descent checklist, turn on the landing lights, adjust to the approach throttle, etc., and at ten nautical miles, it is necessary to contact the Athens tower, because the airspace of Athens Airport is a Class D airspace when the tower is working, and it needs to be controlled before entering the airspace.

The so-called Class D airspace is one of the ways to divide the airspace by the FAA in the United States, and there are six categories of airspace: A, B, C, D, E, and G. Category A airspace above 18,000 feet is an IFR (Instrument Flight Rules) airspace that must be accessed by pilots with an instrument rating endorsement. Class B, C, and D airspace are all controlled airspace, and a regulatory permit must be obtained before entering the airspace, otherwise entry is prohibited.

At a distance of about 10 nautical miles from the airport, the instructor began to do a pre-landing checklist: turn on the landing lights and turn the radio frequency to 126. 8. Adjust the fuel mixing ratio to rich oil, check the flight instrument for damage, etc. The fuel mix ratio refers to the ratio of air to fuel, which is regulated by the cockpit's "mix ratio control lever". Because of the different air densities at different altitudes, pilots need to adjust the mixing ratio to achieve the ideal mixture.

Generally speaking, the higher the altitude, the thinner the air, and the fuel control lever needs to move closer to the lean oil direction, while Xu Wei is preparing to land, and the air on the ground is denser, so he prefers to adjust to the rich oil gear.

Prolonged over- or lean-than-oil periods can cause an engine to stall, compared to a more problematic situation. As long as enough fuel is injected, it is very likely that the engine can be restarted, but the rich oil is not the case, and the excess fuel forms an oil stain covering the spark plug to prevent the spark plug from igniting further, so it is almost impossible to restart the engine.

The checklist is completed, the instructor begins to enter the approach stage, the approach refers to the process of the aircraft descending to the runway flight, in the approach stage, to make the aircraft adjust the altitude, align with the runway, so as to avoid ground obstacles, the pilot must pay a high degree of concentration in order to operate accurately, so the approach is a strict standard and operating procedures.

Generally speaking, there are two main types of approaches: visual approaches and instrument approaches. Instrument approaches are divided into precision approaches (e.g., ILS approaches) and non-precision approaches (e.g., VOR approaches). This is also the test item that Xu Wei will encounter in the instrument grade exam.

The land-air dialogue was done by the instructor himself, and through the headphones, Xu Wei could also hear it.

“athens_tower_c9988_10miles_east_request_to_land。”

The Athens tower responded immediately.

“c9988，ident！”

The instructor pressed a green button on the radio panel and at the same time replied: "ident! ”

This button can be pressed to display the aircraft on the tower controller's radar screen, including the aircraft serial number, altitude, speed, etc., so that the controller can adjust the interval between the aircraft in the jurisdiction.