The weather conditions were very harsh this time, not because of poor visibility, strong winds, and low cloud bases, but because of the great limitations of maneuverability.

In this case, Xu Wei couldn't even get his hands on the most basic maneuvering flight. After the result manipulation, Xu Wei's outlook on life was completely subverted, and he felt that everything he had learned in front of him was in vain. In just one and a half minutes, Xu Wei experienced three stall alarms, and from beginning to end, Xu Wei's muscles all over his body were tightly tensed, and the new students generally maintained an extreme fear of stalling.

When the flight altitude was close to 4,000 feet, the temperature was quite cool, and the instructor chose to stabilize at this altitude and cruise.

The instructor sets the GPS, adjusts the adjustment tab, and the plane enters a stable state.

“what'sdensityaltitudetoday？” Xu Wei was stunned, he only knew the concept of densityaltitude (density height) in a daze, and when it came to specific applications, the meaning expressed was that the second monk was confused.

The instructor saw that Xu Wei couldn't answer his question, so he turned his face on the spot, his eyebrows squeezed into a Sichuan character, and the volume couldn't help but increase a lot. “didyoucheckweatherforcast？”

“yes！” Xu Wei affirmed that he had listened to ATIS before the slide, and the instructor was there at that time, so why did he still ask this question?

“ok？” The instructor raised his eyebrows, as if he was not so surprised by Xu Wei's answer, withdrew his gaze that fell on Xu Wei, and said in a low voice: "areyousure?"

Xu Wei is also angry now, obviously listening to it with you and still questioning me? Fortunately, Xu Wei wrote down all the data when he listened, and immediately turned out the data and repeated the weather information, including temperature, cloud base height, wind direction, wind speed, and visibility.

“that'sit?” The instructor raised his eyebrows, as if he was about to find fault at any time. Xu Wei knew that it was not good when he saw this, and the instructor still looked like this after listening to his explanation, and he would never be untargeted, so it was very likely that he was in addition to his own mistakes.

Xu Wei tried hard to recall ATIS, and suddenly, he seemed to remember that there was a "remark" at the end of ATIS, but he didn't care much about it because he didn't understand it and the main meteorological data was already complete. He was almost sure that the problem was in this "remark", Xu Weideng's heart sank to the bottom, it was over, he dug a pit and jumped into it today, and there was no reason to defend himself.

Sure enough, the instructor immediately mentioned "remark", and Xu Wei didn't have any room to defend himself at all, it was completely his carelessness. I just let it go, and I told the instructor, I just forgot, what do you like, you are not afraid of boiling water to kill pigs.

The instructor was stunned by Xu Wei's straightforward tone, and subconsciously adjusted to the ATIS frequency again to listen to it, and patted his chest with relief after confirming that Xu Wei's responsibility was indeed true, for fear that he had trained the wrong person.

Xu Wei was amused by the instructor's behavior, his identities and the instructor's identity seemed to be reversed, and the instructor was obviously frightened by Xu Wei just now, just like a frightened rabbit. The instructor then found that he seemed to be a little lacking in confidence, and he couldn't help but blush, but he didn't care about criticizing Xu Wei.

Xu Wei's mood was a lot more relaxed all of a sudden, and the atmosphere in the cockpit eased a lot, Xu Wei struck while the iron was hot and asked the instructor what densityaltitude was.

The instructor did not answer his words directly, but switched the frequency to ATIS and motioned for Xu Wei to listen to it himself. Xu Wei carefully distinguished, most of the front is exactly what was written before, and sure enough, there is "remark" in the last part of ATIS! "densityaltitude3500ft!" is clearly stated in the "remark".

“densityaltitude3500ftmeanswhat?” The instructor asked from the side.

Xu Wei shook his head innocently.

The instructor scratched his head in annoyance, probably feeling why his students' basic knowledge was so unsolid. However, he did not move, but explained to Xu Wei in detail the relationship between "densityaltitude" and the previous take-off stall.

It turns out that the temperature is particularly high today, up to 31 degrees Celsius. When other conditions are equal, the lift generated by hot air is less than that of cold air, and insufficient lift will greatly limit flight performance, which is why it is clear that Xu Wei pulls the steering wheel back, and the airspeed of the aircraft has been low to a critical point, but it cannot rise.

The so-called "densityaltitude" is the density altitude, in civil aviation, there are many kinds of altitude, barometric altitude, indication altitude, relative altitude, true altitude, and so on. Density altitude is an important indicator of flight performance, and when the density altitude exceeds 3000 feet, pilots must pay attention to the huge loss of flight performance.

Xu Wei is inexperienced, and still chooses conventional take-off in hot weather, which is expected, resulting in take-off stalls, and the engine power of the C150 is slightly inferior to that of the C152, which has exacerbated the stall to a certain extent.