Air Chief Marshal AP Singh today said the US has not made a formal offer to sell the fifth-generation stealth jet F-35 to India and quipped to a US military commander, “Your people don’t even let us go near the aircraft.”Singh was sharing the stage with General Kevin Schneider, Commander of the US Pacific Air Forces, at a press conference on the ongoing multinational air exercise Tarang Shakti. Asked how he judged the F-35, the IAF chief looked at General Schneider and said, “Your people don’t even let us go near the aircraft, and you talk about selling it to us.”Responding to another media query, the IAF chief added, “The US did not show us the cockpit, but allowed us to fly in close formation.” That is how countries protect technologies, he said.General Schneider, while responding to a question on how the US Air Force keeps F-35 technology ‘under wraps’, said, “We talk about information sharing or access, and especially programmes like the F-35. This is not a decision that I make. There are programme-level security classification guides that determine what we are able to share, when we share it, as well as how we protect it.”The F-35 made its debut at a military exercise on Indian soil with Tarang Shakti. Six US Air Force planes have flown in to take part in the drills.On India’s aspiration to procure a fifth-generation aircraft, the IAF chief said, “Yes, the Russians have offered (the Sukhoi-57). But there has been no decision yet.”India has been looking at a stop-gap option for a fifth-generation jet as its indigenous Advanced Medium Combat Aircraft (AMCA) is a decade away.In the past few years, India has observed China expanding its fleet of fifth-generation jets like the J-35 and J-20. Beijing had promised to give 40 J-35 jets to Pakistan, but supplies have not started so far. Analysts see this as China preventing the US from getting a closer look at the aircraft, a possibility if Pakistan gets the jet. Also, India, with its radars, sensors and intelligence gathering largely facing westwards, would get a clearer picture of Chinese fifth-generation jet operations if the Pakistan Air Force uses it.What is a fifth-generation jet?Fifth-generation fighters are fundamentally backed by high-tech computing nodes which synthesise data from separate sensors — AESA radars, electronic warfare suites, and infrared search-and-track systems — to offer pilots a unified, real-time battlespace picture.The airframe features a reduced radar cross-section (RCS) through advanced composite airframes, internal weapons bays and radar-absorbent materials. This ensures survivability in contested airspace.