After the No.2101 "yellow fighter jet" J-20 was exposed, the suspected No.2102 also appeared on the tarmac recently.(Internet Photo)
BEIJING, January 19 (ChinaMil) -- Recently Chinese military fans released online photos of the suspected second "production" J-20 numbered 2102, which had the same yellow painting as the No.2101 J-20 fighter jet exposed at the end of last year.
This seemed to confirm the conjecture that they are of the "small-scale production" model that is about to be equipped in the troops. Fu Qianshao, an air force expert, held that the painting color and serial number indicate that J-20 is close to or ready for finalization and small-scale mass production.
According to Fu Qianshao, the serial number of J-20's prototype plane and technical verification plane has changed three times, which indicates the different status - either R&D or test flight - of the fighter jet.
He explained that the No.2001 and No.2002 fighters that were tested previously are considered technical verification planes, which assumed the similar role to the X-35 that the U.S. developed before the F-35, and they are mainly used for verifying the core technologies of the generation-IV fighter jet such as stealth performance and aerodynamic layout.
No.2011 is the sign of J-20's prototype plane, which is mainly used to carry out test flight and make corrections concerning problems identified during the test flight.
The several fighter jets starting with No.2011 had major changes in appearance, and their aerodynamic shape and stealth performance have been adjusted based on results of the test flight, until the shape was basically finalized with No.2017.
This was a very important period. When a new J-20 plane was numbered 2101, it came into a new status.
According to Fu, the latest nomenclature indicated that the plane may have come to the stage of design finalization for engineering prototype, which can be mass produced on a small scale if it passed the review.
After the test flight verification, the fighter jet will be equipped in the troops, where it also has to have test flight. When it is first used by the troops, its repair reliability and operational convenience has to be continuously improved based on feedback from the troops, Fu added.
As to why No.2101 and No.2102 had test flights with yellow undercoat, Fu believed that the painting of the prototype and verification plane was decided by the plant, while the troops have rigorous specifications for equipment painting, which may be one of the reasons why the two planes still maintain the yellow undercoat.
Fu also held that the current situations show that China's J-20 doesn't need as many prototypes as America's F-35 for test flight. Although the simultaneous test flights of more prototypes can shorten the testing period and accelerate R&D progress, a larger number means a higher cost. That China hasn't used too many prototypes means the development is quite smooth and it has made comprehensive considerations from the beginning.
Generally speaking, the shorter the R&D and test flight cycle for a plane model, the lower its unit price, so once J-20 is equipped in the troops, it will have higher performance-price ratio than other generation-IV planes.
The author is Liu Yang, reporter from the Huanqiu.com. The opinions expressed here are those of the writer and don't represent views of the China Military Online website.