India's LCA Tejas twin-seat trainer mock-up on display at Aero India 2013 for the first time shows it alongside a Rafael Python-5 IR short-range air-to-air missile and a Rafael Derby BVRAAM. The latter is a stopgap in the event that the Astra isn't delivered on time, and also for testing requirements. Also on the mockup are the R-73 and the Astra.
Journalist Tamir Eshel over at Defense Update reports, "Assuming the Astra missile currently developed for the aircraft not meet the full flight envelope performance goals, the IAF and Indian Naval Aviation are integrating the Derby and Python 5 missiles on the aircraft, along with Russian R73 that was slated for the aircraft from the beginning, to meet the required full-operational capabilities level for the fighter. These weapons will be needed primarily to meet the Indian Navy requirement for carrier air defense, as the LCA will begin to replace the Sea Harriers that currently carry those missions with these weapons."