International Civil Aviation Day丨The sky was clear, why was my flight delayed again?

With the arrival of cold waves, rain and snow, large-scale delays at airports in some areas have become the norm. But sometimes, even though you have predicted the weather conditions in advance and made adequate preparations, you are still waiting to board the plane, and what you are waiting for is the message "We are sorry to inform you that your flight cannot take off on time." If you are unlucky, it will be directly cancelled . Why is the plane delayed when the sky is clear at the take-off and landing place? Why do other people's planes take off on time, but you have to wait for a long time at the same place?

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Today is International Civil Aviation Day. Let’s talk about the real reasons behind flight delays and how to better deal with delays.

01

Why is it so difficult for airplanes to take off on time?

You need to understand the concept of flight delay first

In the past decade, civil aviation has added more than 3,000 new routes, the number of transport aircraft in 2022 will exceed 4,000, and the number of passengers transported will exceed 250 million. With its fast and comfortable features, airplanes have become the first choice for most people to save time. But even in today's mature aviation industry, flight delays have become a reality we have to face, so much so that many ticket booking platforms now sell flight delay insurance on the ticket payment interface.

According to the relevant content of civil aviation operating rules, air transportation is a flight service that transports passengers and their luggage from the starting point to the destination within the expected time according to the flight schedule approved by the authorities and using the specified aircraft along the planned route. If the transportation time exceeds the expected planned time, it is deemed as a flight delay .

According to official data from the "2022 National Civil Aviation Flight Operation Efficiency Report" released by the Civil Aviation Administration of China, the take-off delays at domestic airports in 2022 were mainly concentrated in less than 30 minutes, accounting for 52.83% of flights, and a total of 2.56 million flights were canceled nationwide .

Many people will attribute the cause of flight delays to the airlines, but in fact, the airlines are only partially responsible . As transportation companies, airports and airlines are more reluctant to see flight delays than passengers. After all, the "butterfly effect" caused by the delay of a route may cause a group of people to be unable to get off work on time...

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02

The real reason for flight delays is more complicated than you think

Reason 1: Weather

Meteorology and aviation safety are like the relationship between fish and water. Severe weather conditions are one of the most common causes of flight delays. For example, rain, snow, thunderstorms or weather with low visibility will have a great impact on the flight of the aircraft. According to the "2022 National Civil Aviation Flight Operation Efficiency Report", among the 120,300 abnormal flights nationwide in 2022, the most abnormal flights were caused by weather reasons, accounting for 67.14%. In 2022, the proportion of abnormal flights caused by weather reasons in each month of the year exceeded 50% . In July and August of each year, severe convective weather occurs frequently, and these are also the two months with the highest flight delay rates. This period is the period when heavy rainfall and floods are most frequent in North China to Northeast China, and coastal areas are also susceptible to typhoons and storm surges.

In winter, the heavy fog, rain and snow that come with cold waves will not only affect the visibility of the aircraft, but also require aircraft with snow to undergo a complete set of de-icing work before take-off, and the airport must be cleaned and snow removed to ensure that the aircraft takes off and lands under safe conditions. These may cause the flight to be unable to take off as scheduled.

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Some people may ask, why did the airport broadcast tell me that "the flight could not be scheduled due to weather conditions" when the sky was clear outside the window? In fact, clear weather does not mean normal weather for flying. Wind shear (i.e. sudden and drastic changes in wind direction and wind speed in the horizontal and vertical distances in the air), air turbulence, and air ice accumulation caused by supercooled water are all key meteorological factors that affect aircraft flight . At the same time, airplanes have fixed routes from one place to another. If the area they pass through encounters a large-scale thunderstorm area, the flight will have to fly around, which may also result in delays, diversions, or return flights.

Reason 2: Air Traffic Control

Air traffic control is the business of managing and controlling the air activities of aircraft (including civil airliners, helicopters and other aircraft that perform missions in the atmosphere). It is one of the key means to ensure civil aviation safety. As we all know, the planes we take do not fly freely in the vast sky, but need to fly according to designated routes. Therefore, air traffic controllers are needed to direct and arrange the takeoff and landing of aircraft to ensure that each aircraft can maintain a safe vertical and horizontal distance from other aircraft in the sky , just like cars need to maintain a distance when driving on the road.

When there are too many aircraft in a certain airspace, the number of aircraft entering this airspace needs to be limited to ensure safety. If the plane you are on happens to encounter "traffic congestion" in the air, the plane may be arranged to land and wait at a nearby airport, or it may need to wait for the take-off permission of the traffic controller before taking off.

Sometimes, I am still waiting on the same route at the same time, watching others fly away. I can't help but feel angry. Is it because I have a bad character? In fact, different airlines will choose the route that suits them according to the specific flight conditions. Generally speaking, airlines will give priority to flights with high passenger load factors and flights operated by large aircraft to minimize the impact on subsequent flights. Another possibility is that your flight crew has exceeded the time limit...

To ensure flight safety and avoid "fatigue driving", the crew can no longer fly after reaching the time limit. At this time, the airline needs to deploy other crew members to fly.

In addition, if there are important military or diplomatic activities or due to national confidentiality requirements, airspace control may be implemented . At this time, your flight will need to "give way" and may receive a delay or cancellation notice.

Reason 3: Aircraft technical failure

Although aircraft are carefully inspected and maintained every day, it is still difficult to avoid damage to some parts due to the complex internal structure of the aircraft, and it takes a certain amount of time to replace or repair these parts. If the aircraft you are on has a fault message during the previous flight, in order to ensure the safety of passengers, the airline needs to eliminate the fault before the aircraft can take off normally.

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Reason 4: Human factors such as passengers

If we talk about the first three external factors that lead to flight delays, we as passengers may account for a quarter of the reasons.

Generally, airports and airlines will try their best to ensure that late passengers can board smoothly. At this time, the crew of the aircraft needs to postpone the request to the controller for take-off, and the aircraft will need to wait longer. In addition, passengers leaving without saying goodbye will also cause flight delays. For example, direct passengers leave at the airport where the aircraft stops. In order to ensure the safety of the remaining passengers, the crew needs to confirm that the departing passengers have no belongings left on the aircraft. This requires the crew to check the cabin and checked baggage, including the communication time between staff members and the time to transport baggage to the apron. These situations will cause flight delays.

The rise of drones has also become a "hidden danger" that affects flight safety. In October this year, Shenzhen Bao'an International Airport temporarily restricted some flights due to the appearance of "unidentified flying objects" in the surrounding area. According to Air Travel, the flight delay rate reached 97%.

Some passengers are curious and touch and bump things around on the plane. If they accidentally touch the emergency exit, it may not only lead to flight cancellation, but in serious cases, they may even be detained for moving aviation facilities without authorization! We would also like to remind all passengers to abide by the relevant laws and regulations on civil aviation when taking a plane, and refrain from any behavior that endangers aviation safety .

The development of the civil aviation industry has made "returning from Jiangling in one day" no longer an illusory sigh. The International Air Transport Association (IATA) predicts that the total global air passenger volume will reach 4 billion in 2024. If you are reading this article and have travel plans at the moment, remember to make plans in advance. You need to pay attention not only to the weather conditions at the departure and destination, but also to the weather conditions of the places along the flight route; secondly, arrive at the airport in advance, make backup plans, and understand the handling measures for flight delays or cancellations in advance so as to respond flexibly to emergencies. Finally, follow the instructions and arrangements of the airline. Most companies do not want to lose every one of their customers, and airlines as a service industry are even more so. Therefore, they will do their best to give us reasonable explanations and sufficient help.

In general, flight delays are a common phenomenon, but most of them will not have a big impact on our travel. Being patient and understanding, and communicating well, will help us better deal with flight delays and make our travel smoother.

References

[1] Civil Aviation Administration of China. Explanation of issues related to the Convention for the Unification of Certain Rules for International Carriage by Air[J]. China Civil Aviation, 2005(08): 26-27.

[2] https://www.un.org/zh/observances/civil-aviation-day

[3] http://www.caac.gov.cn/INDEX/

Author: Du Zhiqiang, a master student in transportation engineering at the School of Civil Aviation, Nanjing University of Aeronautics and Astronautics

Reviewer: Deng Xiaotao, Senior Engineer, AECC Hunan Power Machinery Research Institute

Produced by: Science Popularization China

Produced by: China Science and Technology Press Co., Ltd., China Science and Technology Publishing House (Beijing) Digital Media Co., Ltd.