Why do new aircraft models need to be tested so many times?

In order to ensure flight safety and safeguard the public interest, countries have implemented mandatory review and certification for civil transport aircraft entering their own markets. Therefore, C919 large passenger aircraft, like other civil aircraft, must be designed in accordance with the airworthiness standards promulgated by the state, must have a suitable system to ensure that the design of the aircraft meets the airworthiness standards, and must be verified through calculation, analysis, inspection, testing, etc., whether it meets the airworthiness standards. Only after the Civil Aviation Administration of China has passed the airworthiness certification and obtained the airworthiness certificate, the C919 can enter the market.

This system and practice is called "airworthiness" in the aviation industry, and one of the important contents is commonly known as "test flight". There is a saying in the aviation industry that "the development of civil aircraft, airworthiness first". Airworthiness is also a core component of a country's comprehensive aviation strength.

From the first flight to the acquisition of the type certificate, a new large passenger aircraft mainly goes through the stages of R&D test flight, conformity test flight, type qualification certification test flight, etc., and more than 1,000 compliance verification tests such as high temperature, high humidity, high cold, large crosswind, splashing water, minimum ground clearance, stall, flutter, etc.

Like flight tests, ground conformity verification tests are an important part of airworthiness verification. For example, the strength test includes the ultimate load static test of the whole machine, the fatigue test of the whole machine, the nose bird impact test, the component fatigue test and the component bird strike test. <>

China's self-developed ARJ21 regional jet airliner obtained the type certificate issued by the Civil Aviation Administration of China after completing 300 ground test subjects, 528 verification flight test subjects, a total of 2,942 test flights, 5,258 flight hours, 398 airworthiness clauses closed, and 3,418 compliance reports were approved.

Of course, the test flight also needs to be safe. The modern airworthiness regime not only maintains a high level of safety for aircraft entering the route, but also strives to protect every test flight of the aircraft - the aircraft must undergo airworthiness inspection by the civil aviation authorities, be confirmed to be in a safe and usable state, and obtain a special flight certificate before flying. <>

Test flight is a technical verification of aircraft design and manufacturing, and these verifications themselves also need corresponding technical means to carry out and realize. Aircraft hardware changes are often required during test flights, and these changes are often implemented in different parts and for different lengths of time on board, which have complex and cross-linked effects on the flight. For example, the test flight needs to freeze the software configuration as soon as possible, but the brake control system and automatic flight control system need to continuously obtain data and adjust the parameters during the test flight before the design software can be gradually frozen.

Because it is necessary to ensure the safety of the new model before it can be put into use, the test flight many times shows his rigor.

Because the safety of the airplane is not guaranteed, it is very bad if there is a birth accident.

This is because this is to ensure the flight condition of the new aircraft in all conditions and to ensure the safety of passengers.

Of course, the new model will be affordable many times. Well, also to avoid accidents later.

Because every aircraft is likely to have vulnerabilities, it is certain that a lot of tuning will be required beforehand.

This is mainly because it is necessary to ensure its safety, mainly because it is still necessary to fly in the sky.

Because the birth of a new model needs to test whether its safety is up to standard.

I think the first thing is definitely to ensure safety, and the second is to improve the technology to achieve the best and the best.

This thing has its own conditions, so it's like this, and it takes many flights.

Generally, there are several functions, 1, to provide protection, such as the failure of wireless communication leads to the interruption of contact with the ground command, which can guide the return home.

2. The accompanying aircraft crew can test the external data and information of the aircraft in different altitudes, angles and other physical environments at close range.

The prototype of the test flight is a combination of the quality of each component without identification, and the stability in the stationary state on the ground does not mean whether it is stable in high-speed flight. So the test flight is also a very scary thing, the test pilot is a thousand excellent pilots.

Prevent pilots from escaping.

If you really fly away.

The companion plane will destroy the plane, secrecy measures.

This time, I guess it's to observe the flight status of the new aircraft. It should not be accompanied by an aircraft on every test flight.

Photographs of the flight conditions in a timely manner allow the expert group to identify problems and use them as a basis for subsequent studies.

1. It is accompanied by observation;

2. Take photos or videos to record the flight status;

I think it's a record...