While the Pentagon downplays China’s rollout this week of what appears to be a jet fighter designed using sophisticated stealth technology, military experts are warning that the aircraft – reportedly capable of besting America’s F-22 in speed and maneuverability – could pose the greatest threat yet to U.S. air superiority.

Decorated Navy fighter pilot Matthew “Whiz” Buckley, a Top Gun graduate of the Navy Fighter Weapons School who flew 44 combat missions over Iraq, says, “It’s probably leaps and bounds above where we are, and that’s terrifying.”

“As a former Navy fighter pilot, going up against something that’s stealthy, highly maneuverable and with electronic systems more capable than mine -- that’ll keep me up at night,” said Buckley, now chief strategy officer at Fox3 Options LLC.

Buckley said photos posted online of the radar-evading Chengdu J-20 jet fighter lead him to believe the aircraft has great stealth capabilities, based on what appears to be a bumpy exterior possibly housing stealth technology, and the lack of external components, such as a gas tank and missiles.

“It was built to reduce radar signatures. You can tell it has some serious stealth technology,” he said. “My F-18 looks like an 18-wheeler on radar. That thing might not even show up.”

The U.S. military's current top-of-the-line fighter is Lockheed Martin's F-22 Raptor, the world's only operational fifth generation fighter. In 2009, Congress capped production of F-22s at 18, relying on the cheaper F-35. Congress does not appear to be reconsidering the cap, which experts call the only real challenger to China’s J-20.

Richard Fisher, a senior fellow on Asian Military Affairs at the International Assessment and Strategy Center, a Washington-based security think tank, says Chinese officials have said that their program is aimed at competing with the F-22 Raptor.

“From what we can see, I conclude that this aircraft does have great potential to be superior in some respects to the American F-22, and could be decisively superior to the F-35,” said Fisher.

Fisher in particular pointed to the Chengdu J-20’s stealth technology and ability to super cruise, or fly supersonically without using fuel-guzzling afterburners. He said it has super maneuverability due to its thrust-vectored engines that allow for sharp turns.

And while the J-20's engine is still in development, Fisher said it's supposed to deliver 15 to 18 tons of thrust, more powerful than the F-22.

“This fighter will likely start entering service in serious numbers by the end of this decade. The Chinese can accelerate this event by purchasing new Russian engines and settling for a lesser capability,” Fisher said.

Experts say it’s hard to say exactly what the J-20’s capabilities are, especially in a fire fight -- but offered a dire prediction: “With China having a fifth generation fighter, the U.S. will lose F-22s faster than previous estimates.”

As for the J-20 pilots, Fisher said the Chinese Air Force has over 500 fourth generation fighters and is making pilot training a priority. .

“China's air training capabilities have increased greatly over the last decade, to include multiple levels of aircraft, better simulators, and more realistic air combat exercises. They will be able to train pilots for their fifth generation combat force,” Fisher said.

Buckley says the U.S. has moved in the opposite direction, dramatically reducing flight-time training for its fighter pilots, choosing instead to use cheaper flight stimulators.

Limiting F-22 production could prove a grave mistake, Fisher said. Referring to the J-20 photos -- and a new video of the fighter taxiing on a runway -- Fisher said:

“There is now every justification for us to be building modernized version of F-22 and to consider capability enhancements for the F-35 that preserve its competitiveness into next decade."

The next generation joint strike fighter is supposed to be the F-35, Buckley said, which is built for use by all services and must encompass the specific and different needs of the Navy, Air Force, Marines.

“When you try to make a jack of all trades, you have tradeoffs,” Buckley said. “It’s obvious that the Chinese are throwing money and technology to making something the best, and here we’re worried that one is going to bankrupt the country.”

“We used be No. 1 at having the leading technology. ... Now, we’re kind of in catch-up mode, where we’ve never really been before.”