The Indian Air Force's (IAF) domestically manufactured Mark-I Tejas light combat aircraft (LCA) is likely to miss its final operational clearance (FOC) schedule planned for the end of this year.
Six aircraft are required for the tests but only one of them is undergoing handling tests in the run-up to the FOC stage.
A source told Defense News: "With handling tests on only one aircraft, and the remaining not even manufactured, it is impossible to get FOC by December's end."
The aircraft undergoing testing is yet to be modified for air-to-air refuelling capability, which is unlikely to happen by the year-end, the source said.
Mark-I LCA received initial operational clearance in December last year.
State-owned Hindustan Aeronautics is under contract to supply 40 Tejas aircraft and eight limited series production (LSP) aircraft to IAF to replace the ageing MiG-21 fighter fleet.
However, the programme has been repeatedly delayed forcing IAF to search for an alternative.
The air force is currently negotiating a deal to buy 126 medium multirole combat aircraft (MMRCA) from Dassault at a cost of more than $12bn.
Last week, scientific adviser to Indian Defence Minister Avinash Chander told the India Strategic magazine that the naval variant of Mark-I had undergone 25 test flights from a runway. It will be deployed at a naval base to commence ramp flights.
Meanwhile, the more advanced LCA Mark-II is also likely to miss its 2018 flight testing deadline, as the Indian Government is yet to sign a contract with the US for the purchase of GE-414 engines. Mark-II is designed to address IAF's requirement for heavier payloads
IAF wing commander (retired) Bhim Singh told Defense News: "The Indian Air Force has a requirement of over 200 LCA Mark-I and Mark-II aircraft, but with delays looking imminent and the procurement process of MMRCA getting longer, the Indian Air Force could take a major hit on its fleet strength in the years ahead."
In a report last week, India Today wrote that the IAF needs Mark-II aircraft more than the Mark-I version.
"But that version is on the drawing table. Realistically speaking, we have little hope from Tejas," the news magazine quoted from an unnamed source.
Image: An Indian Air Force's light combat aircraft in flight. Photo: courtesy of Rinju9.