The HAL Tejas design has been further developed into the Tejas Mark 2, incorporating a more powerful General Electric F414 INS6 engine, canards and other design changes. The Tejas Mark 2, which is expected to be rolled out in 2022, will have an increased payload carrying capacity and internal fuel capacity, more external hardpoints, improved combat range, a completely redesigned cockpit, and an integrated infrared search and track (IRST) system, in addition to the AESA radar. The Defence Institute of Advanced Technology (DIAT) is developing aircraft health and usage monitoring systems (HUMS) to integrate the various sensors on board the Tejas Mark 2. The first flight of Tejas Mark 2 is expected to be in 2023. Naval variant The Naval LCA programme was commenced in 2003. According to ADA, the Naval LCA (N-LCA) Programme was envisaged to be completed in two phases, under Phase-1 two naval prototypes were developed - the two-seat NP-1 and the single-seat NP-2, based on the Tejas Mark 1 design, to carryout carrier suitability certification and weapons integration. Under Phase 2, two single-seat prototypes were planned to be built, based on the Tejas Mark 2 design, with further design optimisation and integration of the General Electric F414 INS6 engine. The first naval prototype NP-1 was rolled out in July 2010, and made its first flight on 27 April 2012. The naval LCA has stronger landing gear to absorb the forces generated during carrier take off and arrested recovery. In December 2014, the LCA Navy successfully made its first ski-jump assisted take off from a SBTF at INS Hansa. The navy variant has a distinctive flight control law mode which allows hands-free take-off. In December 2016, the Indian Navy (IN) opted out of the programme, owing to the long delay and technical reasons – such as inadequate thrust to weight ratio of N-LCA for carrier based combat operations, and issued a fresh RFI for the procurement of 57 multi-role carrier borne fighters. Because the technologies developed for the Tejas programme will be carried over to other platforms currently being developed by the ADA, test flying was continued. In 2019, an LCA navy prototype successfully carried out the first arrested landing at the SBTF in Goa in day time and night time. As of December 2019, the Naval LCA programme completed 209 test flights, of these 50 were ski jump take-offs. In January 2020, the naval prototype NP-2