Beijing: Developed jointly by Pakistan and China, the JF-17 fighter jets have failed to keep narratives peddled by Beijing media that the country's modern aircraft are the best in the world as Islamabad's experience with the jets tell a different story, according to media reports.

Taiwan News reported that Pakistani leaders expected a low-cost, lightweight, all-weather multi-role fighter, something akin to the Russian Su-30MKI or the French Mirage-2000 but the reality fell well short of their high hopes.

In 1999, when Beijing and Islamabad signed the deal on joint production of the JF-17, it was touted as a combat jet comparable to Su-30MKI, MiG-29 and Mirage-2000. The reality, Pakistan Air Force (PAF) is finding out much to its chagrin, is nowhere near the boastful claims made by the Chinese, Daily Sun reported.

The first images of Pakistan's new mass-produced JF-17 Thunder (Block III) have surfaced in recent days. The new version is hoped to be a radical departure from the clunky earlier JF-17 models, yet questions hang over the extent of its supposed upgrades.

Since JF-17 operational induction in 2009, downing have been all too common. In 2012, Pakistani media recorded a string of 12 crashes over 18 months, among which were several JF-17s, Taiwan News reported.

In August last year, another newly built dual seat model crashed only a year after being made and 96 hours of flight time, according to Pakistani newspaper Dawn.

Though the PAF has brought over 100 JF-17 Block Is and Block IIs into active service, due to a shortage of spare parts, approximately 40 aircraft are not airworthy, per reports.

A large number of engines in JF-17 have reportedly experienced cracks in guide vanes, exhaust nozzles, and flame stabilizers. The engine of the JF-17 is the Russian-made RD-93.

The publication also reported that the shoddy engines are also hard to replace, in part due to US sanctions on the Russian supplier agency, which has caused complications with dollar-denominated transactions.

However, the latest images of JF-17 show no visible changes to the exterior of the engine, suggesting it is probably fitted with the Klimov RD-93MA or even the same legacy RD-93, though this has yet to be confirmed. Regardless of how it performs, if it is a Russian engine again, serviceability will continue to dog the platform in the future.