The Kaveri powerplant for India's Aeronautical Development Agency/Hindustan Aeronautics Ltd Tejas light combat aircraft has experienced cost overruns seven times the initial estimate, while costs for the Tejas Mk II and naval variant of the Tejas have also risen sharply.
The cost of developing the Kaveri was revised to Indian rupees (Rs) 28.39 billion ($560 million) in 2009, up from the original estimate of Rs3.83 billion allocated to the project in 1996, says Indian minister of defence A K Antony in a written reply to a question in parliament.
Costs involving the Tejas Mk II have nearly doubled to Rs57.77 billion from an expected Rs33.02 billion, while costs involving the naval Tejas have risen to Rs17.5 billion from Rs9.48 billion.
The Kaveri is being developed by the Gas Turbine Research Establishment (GTRE). Antony noted that the engine was tested for 55 hours mounted on an Ilyushin IL-76 test aircraft in Russia, and operated at an altitude of 12,000m (39,370ft) and a speed of Mach 0.7.
India announced the IL-76 tests in November 2010, saying they would pave the way for mounting the Kaveri aboard a Tejas aircraft. Since the tests, however, there has been no official announcement of any attempt to marry the engine to the Tejas.
An industry source familiar with the Tejas programme recently told Flightglobal that the Kaveri programme still exists, but is stalled.
The Kaveri has a troubled history. It reportedly suffers from both weight and performance issues, failing to provide the 21,000-22,500lb (93-100kN) thrust needed to power the Tejas. This caused it to be de-linked from the Tejas programme.
The Tejas Mk I uses the General Electric F404 powerplant, while the planned Tejas Mk II will use the General Electric F414 powerplant.
Antony also told the parliament that the Kaveri could be used to propel an Indian unmanned strike air vehicle (USAV), although he provided no details about this programme. Such a use could suggest that India's defence ministry has abandoned hopes of using the Kaveri aboard the Tejas.
Indian officials have also spoken of using two Kaveri engines aboard India's conceptual medium combat aircraft (MCA), an aircraft roughly equivalent to the Lockheed Martin F-35 Lightning II.