First of all, provide a reference for this claim. From where do you understand that L-15 is a development of Yak-130?
Dude there are tons of sources on this. I think its better to admit ones mistake or misunderstanding and move on rather to try to dig in and defend a misconceived idea.
China actually has two variants of the L-15 in service. The one with their Navy does not have an afterburning engine and the dimensions are slightly different (no radar in that one either I believe). For reference, look at the pictures posted by AzadPakistan and compare the lack of engine nozzles on the last one with the ones above.
Anyways, I will try to post a recent article on this trainer for you guys
From Combat Aircraft Dec 2018 issue...
A new generation
Perhaps the most eagerly awaited trainer to enter PLAAF and PLA Naval Aviation service is the Hongdu JL-10 Falcon.
This type — which began life with the export designation L-15 — is an advanced jet trainer (AJT) developed with technical assistance from Yakovlev OKB. The JL-10 was designed to school pilots for a new generation of Chinese fighters including the J-10, J-11, J-15, J-16 and J-20.
From the outset it was planned to develop two different versions: the standard JL-10/L-15A AJT, powered by two Ukrainian AI-222-25 turbofans, and a dedicated L-15B LIFT, powered by two AI-222-25Fs with afterburning to provide supersonic capability.
As a new design based on the Yak-130, the JL-10 makes use of a more modern airframe — especially in comparison with the rival JL-9 — with prominent leading-edge root extensions (LERXes), a large vertical tail fin and a modern aerodynamic configuration which is expected to allow maneuvers at angles of attack of up to 30 per cent. The cockpit is much more advanced than that of the JL-9 — it’s a fully digital glass environment with HUD, three color MFDs, hands on throttle and stick (HOTAS) controls and three-axis quadruplex digital FBW. For weapons training, the JL-10 has four underwing and two wingtip pylons for a wide variety of stores plus an optional gun pod underneath the fuselage. The standard JL-10 is equipped with a small radar, while the L-15B can even carry a small passive electronically scanned array (PESA) fire-control radar.
The first prototype L-15 AJT was completed in September 2005 and its first flight was completed — after delays due to engine problems — on March 13, 2006. The first example was powered by two interim DV-2 turbofans and was followed by an improved AJT prototype using two AI-222-25 turbofans that took to the air on May 10, 2008. However, development of the LIFT version still suffered from the slow progress of the afterburning AI-222K-25F. It finally few for the first time on October 26, 2010. The machine differs from the JL-10 on account of a stretched forward section and longer rear section, and is powered by two AI-222K-25F turbofans with prominent afterburner nozzles.
A first ‘true’ domestic AJT version, designated as the JL-10, was finally unveiled before its first flight on July 1, 2013. Since then, several prototypes have been noted undergoing testing and, based on images from mid-2016, it was assumed that the type was in series production for both services, an assumption confirmed in early 2017. Naval aviation received its first aircraft — dubbed the JL-10H — in March 2017. In future it seems as if the L-15 will be fitted with domestically produced engines. The standard JL-10 is planned to receive an indigenous turbofan without afterburning (actually an AI-222-25 copy), which was flown for the first time in May 2016.
The L-15B is thought to use the WS-17 Minshan turbofan with a maximum thrust of 10,362lb (4,700kg) with afterburning, developed by the Guizhou Aero Engine Research Institute. The same engine is rumored to have been tested on an L-15 prototype. Since September 2013 there have been suggestions that the JL-10 might be adopted by naval aviation as a carrierbased trainer, possibly based on the L-15B airframe with the more powerful engines. This remains unconfirmed.
At least three different variants are currently available for export: the standard L-15A, comparable to the JL-10 and the L-15Z already in service with the Zambian Air Force; the L-15B, based on the LIFT version and available with combat-capable avionics; and finally the L-15C, which combines the L-15B’s avionics with the airframe of the L-15A. The Chinese training aircraft family is steadily expanding into new markets and will perhaps pave the way for more extensive global fighter sales in future.