Northrop Grumman provided a first look at its vision for the sixth-generation fighter in December. One of the most complicated parts, analysts have noted, is that if the stealthy planes include lasers, they will need to be built in a way in which the heat doesn’t give them away on enemy radar.
The United States Air Force and United States Navy are anticipated to field their first sixth-generation fighters in the 2025–30 time frame. The USAF is pursuing development and acquisition of a sixth-generation fighter through the F-X program to replace the F-22 Raptor, and the U.S. Navy is pursuing a similar program called the Next Generation Air Dominance to replace the F/A-18E/F Super Hornet
The sixth-generation fighters are expected to use advanced engines such as Adaptive Versatile Engine Technology to allow longer ranges and higher performance. Risk reduction began in 2012 so that engine development can start around 2020. An engine is to be ready when fighters are introduced by the Navy in 2028 and the Air Force in 2032
In September 2011, Boeing unveiled a sixth-generation fighter concept for the U.S. Navy and Air Force. It is planned to have supercruise and fly faster and further than the F-35 Lightning II. Boeing is self-funding the project until an official fighter program starts to have a design ready.
Lockheed Martin's Skunk Works division has revealed a conceptual next-generation fighter design that offers the first hints of an ambitious, long-term technology strategy for the new class of tactical aircraft that will emerge after 2030. The concept was published in a 2012 calendar, which was distributed to journalists. Lockheed Martin has called for greater speed, range, stealth and self-healing structures.
In January 2015, Northrop Grumman revealed it had stood up teams dedicated to developing a sixth-generation fighter and that it would compete for the next fighter. Individual teams were created to focus on the specific separate requirements for the Navy and Air Force. The company indicates it is looking at a supersonic tailless jet, something never created before due to complexity; it may also be optionally manned.
SOURCES - Washington Post, Wikipedia, Youtube