This article is sourced from [CCTV News];

Recently, on the test flight runway of SAC (Shenyang Aircraft Corporation) in the aviation indus-try, a J-35 fighter jet, painted with green primer, took off and soared into the sky, marking the"first flight of the new year". This signifies the full commencement of the annual test flight work.It is also the first time that the official has disclosed the J-35 flight footage with primer visible.Why is the J-35 test aircraft a "green prototype"?

Firstly, due to the need farcorrosion prevention andbasic protection, the airframeof the J-35 is assembled froma large number of metal andcomposite materials. Duringthe initial stages of manufac-turing, assembly, and flighttesting, the surface of the aircraft is exposed to humid air,making it highly susceptibleto electrochemical corrosion. The green primer contains chromate, which has strong anti-corro-sion and anti-rust properties, providing the most basic and crucial protection for the metal airframe. It is like the "moisture-proof putty" or primer applied on the rough wall surface duringhouse decoration to prevent intemal damage

Secondly, from a practical perspective of engineering test flights, during the maiden flight andinitial test flight stages, the core goal of the engineering team is to verify the basic qualities ofthe aircraft, such as flight performance, maneuverability, and structural strength, while main-taining a simple "green" state, which facilitates inspection, marking, and maintenance of the fu-selage surface by engineering personnelThe third issue is cost

When the design and status are not yet fully solidified, it is a waste to apply expensive officialcoatings. Once the fuselage structure needs to be modified, these coatings will have to be re-moved and redone. As the test flight progresses, the aircraft will gradually enter different stagesof painting. Only when it reaches the mass production painting stage will it be sprayed with theofficial combat coatings

In addition to green, our military aircraft often adopt yellow painting during test flights, affec-tionately referred to by the majority of military enthusiasts as "yellow-skinned aircraft". Thisrepresents the "roughcast" state of the aircraft. Whether it's a "green-skinned aircraft" or a "yel-low-skinned aircraft", both indicate the birth of new models or new capabilities. Let's applaudthese great national treasures!

This article is sourced from: CCTV News official account