REASONS BEHIND DELAY IN TEJAS DEVELOPMENT
# The IAF's Air Staff Requirement for the LCA were not finalized until October 1985. The LCA design was finalized in 1990 as a small tail-less delta winged machine with relaxed static stability (RSS) to enhance maneuverability performance.
# The IAF expressed doubt that India possessed sufficient technological infrastructure to support such an ambitious project.] A governmental review committee was formed in May 1989 which reported out a general view that Indian infrastructure, facilities and technology had advanced sufficiently in most areas to undertake the project.
# THE TEJAS PROGRAMME WAS SPLITED IN THOW PHASES. PHASE 1 WOULD FOCUS ON "PROOF OF CONCEPT" AND WOULD COMPRISE THE DESIGN, DEVELOPMENT AND TESTING (DDT) OF TWO TECHNOLOGY DEMONSTRATOR AIRCRAFT. PHASE 2 WOULD CONSIST OF THE MANUFACTURING OF THREE MORE PROTOTYPE VEHICLES.
# Phase 1 commenced in 1990 and HAL started work on the technology demonstrators in mid-1991; however, a financial crunch resulted in full-scale funding not being authorized until April 1993, with significant work on FSED Phase 1 commencing in June. The first technology demonstrator, TD-1, was rolled out on 17 November 1995 and was followed by TD-2 in 1998, but they were kept grounded for several years due to structural concerns and trouble with the development of the flight control system.
# Development of a FBW flight control system requires extensive knowledge of flight control laws and the expensive writing of a considerable amount of software code for the flight control computers, as well as its integration with the avionics and other electronic systems. When the LCA programme was launched, FBW was a state-of-the-art technology and such a sensitive one that India could find no nation willing to export it. Therefore, in 1992 the LCA National Control Law (CLAW) team was set up by the National Aeronautics Laboratory to develop India's own version. The CLAW team's scientists and mathematicians were successful in developing their control laws, but could not test them since India did not possess advanced real-time ground simulators at that time. Accordingly, British Aerospace (BAe) and Lockheed Martin were brought in to help in 1993, but the effort required for the Aeronautical Development Establishment to code the control laws into the FCS software proved a much larger job than originally anticipated.
# Another critical technology area tackled for indigenous development by the ADA team is the Multi-Mode Radar (MMR). It was initially planned for the LCA to use the Ericsson Microwave Systems multi-function radar, which was developed by Ericsson and Ferranti Defence Systems However, after examining other radars in the early 1990s, the DRDO became confident that indigenous development was possible. HAL's Hyderabad division and the LRDE were selected to jointly lead the MMR program and the radar development effort began in 1997.
#KAVERI ENGINE WAS DECIDED TO EQUIP HAL TEJAS. However, progress in the Kaveri development programme was slowed by technical difficulties. In mid-2004, the Kaveri failed its high-altitude tests in Russia, ending the last hopes of introducing it with the first production Tejas aircraft. In 2008, it was announced that the Kaveri would not be ready in time for the Tejas
# In November 2010, it was reported that the Tejas Mk1 reportedly fell short of the relaxed Air Staff Requirements stipulated for limited series production (LSP) aircraft. The areas that did not meet requirements were power to weight ratio, sustained turning rate, maximum speeds at low altitudes, AoA range, and weapon delivery profiles. The extent of the deficiencies was classified.
# The Tejas was grounded for over three months because of the new pilot’s helmets extended above the ejection seats. The helmets could have prevented a smooth ejection by hitting the canopy before it was blown off. This represented a serious safety issue and flight testing was stopped in August 2012. The ejection systems have been modified to rectify this issue. Flight tests resumed in November with seven successfully completed.