13 Oct 2014:
Here are some details re the GE F414 engine that will power the next gen Tejas – PDF file from GE Aviation. This engine is also shared by the Swedish Gripen fighter jet as well as a few other aircraft. It is heavier but provides higher thrust-weight ratio (9 vs 8) when compared to the F404 that powers the Tejas Mark I. 99 of these engines have been ordered from GE.
The GE engine powers aircraft like United States Navy’s F/A-18E/F Super Hornet and EA-18G as well as the next gen Swedish Gripen. Based on GE press releases, it has more than 3 million flight hours and 1,500 engines delivered. Interestingly, even for GE which is an experienced manufacturer of aircraft engines, with practically unlimited budget afforded by the richest military power on earth, it took 7 years from design to service. This should highlight the challenges faced by Indian researches working on shoe string budget.
Not resting on its laurels, GE is further enhancing this engine with a new compressor and better turbine as well as noise reduction technologies. It is not clear if these improvements will make their way into the Indian version.
It has been reported that the length of the aircraft will be up by about 550mm as a result of using the more powerful engine.
As of now, maiden trials are expected only by 2019 and production from 2024. Janes report
In the meantime, you can drool over the video of LCA Tejas performing at the Bahrain Air show in Feb. 2016
Serial production in 2020? First prototype in 2018-19. Says this article
Improves include: Home-developed Active Electrically Scanned Array (AESA) radars, unified EW suites, on board oxygen generation systems and upgraded avionics.
This seems to indicate considerable overlap between existing version that IAF has committed to purchase and the Mk2.