Tejas Mark-I fails to meet IAF criteria, has 53 shortfalls:

India's Tejas Light Combat Aircraft project, in the works for over three decades, came under severe criticism from CAG today as it pointed out that its Mark-I version has 53 "significant shortfalls" which have reduced its operational capabilities as well as survivability.
Not only that, IAF would be "constrained" to induct the fighter LCA without availability of a trainer model, thereby "adversely impacting pilot training", the audit body said in a report tabled in Parliament.
The CAG noted that it was due to the delay in the manufacture and supply of LCA that IAF had to go for alternative temporary measures such as upgrading its MIG BIS, MiG-29, Jaguar, and Mirage aircraft at a cost of Rs 20,037 crore and revise the phasing out of MiG-21s.

"LCA Mark-I, which achieved Initial Operational Clearance (December, 2013) has significant shortfalls (53 permanent waivers/concessions" in meeting ASR (Air Staff Requirements) as a result of which it will have reduced operational capabilities and reduced survivability, thereby limiting its operational employability when inducted into IAF squadrons," the report said.
Listing the shortcomings, the CAG said that the LCA Mark- I fails to meet the electronic warfare capabilities sought by IAF as the Self-Protection Jammer could not be fitted on the aircraft due to space constraints.
Also, it said that the Radar Warning Receiver/Counter Measure Dispensing System fitted on the aircraft had raised performance concerns which are yet to be overcome till January this year.

It added that the shortcomings in the Mark-I (increased weight, reduced internal fuel capacity, non-compliance of fuel system protection, pilot protection from front, reduced speed) are expected to be overcome in the Mark-II model.

"LCA Mark-I does not meet the ASR. The deficiencies are now expected to be met in LCA Mark-II by December 2018," the CAG said.
While DRDO has always showcased LCA, christened Tejas, as an indigenously-developed aircraft and the indigenous content of the LCA was estimated by ADA to be 70 per cent, the CAG said it "actually worked out to about 35 per cent" as of January this year.

Systems such as Kaveri engine, Multi-Mode Radar, Radome, Multi-Functional Display System and Flight Control System Actuators taken up for indigenous development could not be developed successfully, resulting in LCA's continued dependence on the import of these systems, CAG said.
IAF had proposed in the early 1980s that a new aircraft be developed to replace the MiG-21 fleet, manufactured during 1966 and 1987, after its phasing out in the 1990s.