In December 2022, the domestically produced large aircraft C919 was delivered for the first time. In April of this year, Air China signed an order with COMAC for 100 C919 aircraft. It is expected that the first aircraft in the order will be delivered by the end of August, which is also the first domestically produced C919 large aircraft in history to be painted with the five-star red flag.

In July, this aircraft entered the production process of "spraying" and officially put on the coat of the five-star red flag.

In July, the staff carried out spraying work.

50 people completed the aircraft spraying task in 9 days

The production of an aircraft involves the process of assembly, final assembly, painting, and test flight. Among them, "spraying" is further divided into multiple steps such as polishing, positioning, spraying, and inspection.

Due to the complex shape, large area, and numerous curved surfaces of the aircraft, as well as the sophisticated equipment such as engines, protruding antennas, and movable surfaces, mechanical equipment cannot achieve accurate automated construction, "explained Wang Guidan, senior supervisor of production management. The "spraying" task still requires a manual led and mechanically assisted working mode.

In July, before spraying the aircraft, the staff covered some sensor components on the fuselage.

The "spraying" task was carried out by the "Big Aircraft Beautician" team of COMAC Shanghai Aircraft Manufacturing Co., Ltd. This team of 50 people comes from multiple departments such as the parts machining center, manufacturing engineering technology center, quality control center, and the design team of Shanghai Aircraft Industry Corporation. Their only goal is to turn the C919 with the national flag into a perfect artwork.

In July, the staff polished the aircraft.

During the 9-day spraying work, the staff first covered the non spraying area of the aircraft and polished the spraying area to ensure that the subsequent spraying could adhere perfectly to the aircraft.

In July, after polishing and masking the surface of the aircraft, the staff sprayed green primer on the wings of the aircraft.

The 'gunman' uses a spray gun to spray multiple layers of paint on the aircraft, including green primer (fuselage primer), colored paint, white primer (coating primer), and high gloss varnish. The paint layer is not only for aesthetics, but also adds functions such as anti-corrosion and UV resistance to the body.

In July, the staff wore protective clothing and sprayed high brightness varnish on the aircraft.

During the painting process, the paint surface appears atomized. To avoid inhalation into the human body, workers need to wear tight and poorly ventilated protective clothing during work. Despite the constant temperature and humidity inside the hangar, after one set of operations, their entire clothes and goggles were soaked in sweat.

In July, the staff carefully inspected the details of the plane's paint surface and found that the mask was already covered in mist.

Master craftsman level master

Responsible for painting the national flag

This spraying is the first time in history that the national flag pattern has been sprayed on the C919 aircraft. Although the team has experience in spraying other types of aircraft, the work plan cannot be fully applied due to differences in data such as aircraft length, width, and size. This also brings new challenges to the spraying team.

The spray painting team has selected several "craftsman" level masters to be responsible for the spray painting of the five-star red flag on the fuselage. The paint thickness of the national flag needs to be very precise. If the paint surface is thick, it is easy to peel off, and if it is thin, it is easy to have burrs, "said Zhang Weibing, the leader of the fourth paint spraying group." We need to ensure the smoothness and absence of particles on the surface of the national flag. "He is the oldest master in the entire team and has been engaged in paint spraying work for 36 years.

In July, the staff carefully checked the aircraft painting and spraying plan before spraying.

On the mobile spray painting platform, three staff members crouched down and meticulously marked the outline of the pentagram, ensuring that each vertex and edge were strictly aligned. Before the formal spraying, they will conduct a trial spraying to familiarize themselves with the fluidity of the paint and the spraying pressure, ensuring proper control during the formal spraying.

A staff member stabilizes their arm and slowly sprays along the pre marked contour line, keeping the angle and distance between the spray gun and the sprayed surface consistent. Another staff member shone a flashlight on the national flag area, and the two of them observed together to ensure that the paint thickness was perfect.

In July, the five-star red flags on both sides of the aircraft's fuselage were drawn.

Although the entire hangar is now in a dust-free environment, the masters still need to cover the flag area specifically after spraying the red primer to ensure the cleanliness of the flag surface as much as possible.

The process of "spraying paint" requires extremely high precision and uniformity, which is commonly known as "painting". The aircraft model identification, character identification, aircraft sensor indication, emblem and other markings need to be accurately and finely sprayed on the aircraft, which requires on-site positioning through manual and laser projection.

In July, staff made detailed adjustments to the aircraft model paint on the fuselage of the plane.

After determining the positions of each identification, they need to rely on their exquisite skills and sensitivity to color to spray paint and draw the identification on the machine body. After completing the high gloss varnish spraying, the engineer conducts a strict inspection and retest of the uniformity and flatness of the entire body paint.

In July, the staff sprayed high brightness varnish on the aircraft.

Regarding the national flag, the experienced technicians conducted another re inspection using high light flashlights to ensure that the spray quality of each C919 aircraft meets the highest standards.

In July, staff used high-powered flashlights to recheck the national flag.

Overcoming technical difficulties and challenges

Refine the spraying process

When performing flight missions at high altitudes, the outer surface of the aircraft is subjected to strong sunlight and significant temperature differences. This requires the surface paint layer of the aircraft to remain stable in extreme environments, ensuring flight safety.

In July, after the aircraft's fuselage was painted, the staff carefully inspected the surface.

The surface paint layer of the aircraft not only serves the purpose of aesthetics, but also isolates external substances, effectively delaying the corrosion of the fuselage. If there are defects in the production process of "spraying", the paint layer is prone to aging and peeling, causing corrosion of the aircraft and affecting its service life and safety. The frequency of aircraft maintenance and painting will also increase, affecting the passenger operation of the aircraft.

In order to address the technical difficulties and challenges in the painting process of the C919 aircraft, the painting team has introduced advanced painting equipment and technological innovations, including mobile painting platforms and laser projection technology, greatly improving the flexibility, efficiency, and accuracy of painting.

At the end of July, this C919 successfully completed its spraying task. On August 9th, the first test flight was completed, and by the end of the month, it will be delivered to the airline.

In July, the aircraft was painted and sprayed.

After the airline completes a series of checks on the flight training and route operation experience qualifications of the crew, this domestically produced large aircraft wearing the five-star red flag will be put into commercial operation.

In July, after the completion of the aircraft spray painting, the complete machine spray painting workshop was launched.