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.