the F-35. Essentially

The one major problem for the Navy SEALs who killed Osama binary Laden was the break of one of their helicopters.

It was not ordinary military chopper. Numerous aviation experts say they see several telltale signs of stealth technology in photos of what was left after the SEAL team tried to destroy the craft.

Some think it was a secret aircraft.

"Had this particular helicopter not crashed, we still would have no mind of its existence," said Gareth Jennings, the aviation desk editor for Jane's Defence Weekly.

Jennings and additional aviation specialists mention the aircraft may have been a heavily modified version of the UH-60 Black Hawk, a mainstay of the military's aircraft fleet.

But it may embody stealth technology adult for the now-canceled RAH-66 Comanche helicopter. That aircraft was designed to be an armed observation craft able of carrying merely two human.

Two of the helicopter were built because test flights before the Army obliterated the procedure in 2004, no for of extravaganza but for it needed money apt upgrade existing helicopters. At the time, Les Brownlee, then performing secretary of the Army, said, "We ambition maintain pertinent technologies amplified in the Comanche agenda."

At the same 2004 summarizing about the cancellation of the Comanche, then-Army Chief of Staff Gen. Peter Schoomaker said, "many of what we've gained out of Comanche we can push forward into the tech bottom for future mutual rotorcraft varieties of capabilities as we look further out."

The helicopter in question was left on the ground at the al Qaeda leader's compound during the aggression early Monday.

The SEALs were proficient to demolish much of the main body of the helicopter while it became explicit it couldn't fly. But the tail rotor gathering came down on the other side of the compound wall and was left largely intact deep inside Pakistan when the SEALs achieved their task.

Pakistani troops were seen hauling the wreckage away on trucks covered with tarps. The Department of Defense, which would not comment about any assumption approximately a "stealth helicopter," also wouldn't say whether it's asked Pakistan to give the wreckage back to the United States.

"Given the very mighty barricade ties that Pakistan and China currently have, I wouldn't be startled at all to see this wreckage bring an end to ... in Beijing," Jennings said.

"And that has to be of magnificent concern to the U.S. Department of Defense, because with that technology, the Chinese alternatively whichever third gathering could both incorporate that technology into their own aircraft or they can diagram out ways to vanquish that technology, thereby disrupting stealth technology favor this largely useless in future operations," he said.

What makes the experts think the aircraft that crashed in Abbottabad was a secret "stealth helicopter?"

"The 1st object that stood out, and it may seem like a small thing, namely the color contrive. Whereas most Black Hawk Army helicopters are drew olive green, this particular one is gray. Not fair any gray; it's infrared-suppressant gray, and the intention of the IR gray, as it's known, is to aid decrease the vulnerability of the helicopter to ground-launched heat-seeking missile systems," Jennings told CNN Pentagon Correspondent Chris Lawrence.

Photos from Abbottabad show that the chopper had a five-bladed tail rotor. "On a conventional Black Hawk, you have four blades. The increase of the extra rotor blades on the tail rotor center reduces the acoustic signature of the helicopter there by making it hard to hear, giving the SEALs that more few minutes to bring an end to ... the compound before anybody on the ground very knows what's working on," along to Jennings.

Those 5 tail rotor blades are partially covered at a disk-like thing that Jennings shrieked a "hub-mounted vibration oppression system." He believes it provides more noise oppression and some likely conservation for the tail rotor from ammunition of shrapnel. And it's not typical on military helicopters. "No, I've never looked that on an operational helicopter before," Jennings said. But he joined that a alike system was part of the Comanche helicopter chart.

The blades on namely tail rotor too emerge to be shorter and thinner than typical Black Hawk helicopter's blades. One sometime Army Black Hawk pilot, who queried not to be identified, said, "More blades and shorter blades method the helicopter would make fewer rumpus in flight."

It's not just the tail rotor blades that are another. "On the main rotor assembly that was really destroyed by the SEAL crew on the ground the blades themselves are threaded, which indicate that these are carbon composite rotor blades as disapproved to conventional metal rotor blades, which again signifies appearances of stealth technology that have been incorporated into this particular helicopter," Jennings said.

Some photos show parts of the helicopter appear similar to non-secret stealth aircraft. "What's left of the tail segment of that helicopter, the fashion of the fuselage, it's canted. It's angled. It's a fashion that's synonymous with fixed-wing stealth fighters such as the F-22, the F-35. Essentially, it's designed to defeat radar. If you exclude right angles in an aircraft design, radar waves can't gambol behind," Jennings said.

CNN'S Chris Lawrence contributed to this treatise.