Did you hear about the 'Alien Autopsy' in Area 51? Its top secret. The govt. denies it, but there are pictures and witnesses.
Are you referring to Roswell incident. Roswell, a small town, is a USAF base in New mexico and Area 51 is a secret base in Neveda, out of bounds for civilians. Area 51's existence is denied because of the top secret military projects. B-2 and F-117 were tested here, flying only during nights to prevent soviet spies from taking pictures.
Regards Roswell incident, its not an alien landing. NASA used to test its high-altitude baloons, re-entry vehicles and high-altitude ejections - HALO jumps over roswell. HALO stands for High Altitude Low Opening, means the paratroopers/pilots jump out of plane at a very high-altitude and falls freely to ground and opens the chutes at a low altitude.
The instant a person jumps out of plane flying at high speeds and high altitudes without any protection, the air gushes into the body and tears ur nostril and cheeks and the face bloats. Pretty bad sight. These days people use helmets and oxygen masks for HALO jumps and its safe.
The 'Alien' which people saw at Roswell site was none other than a human subject doing HALO (this was also tested on bears and monkey's) and his face swelled like a pumpkin, and looked like an alien. These documents were recently declassified and pictures/videos of the pilot, bear and mokey were released to general public. I have seen the pilots picture on TV, he looked like an alien .
People also cite the American stealth planes B-2 and F-117 as an example of alien technology, reverse engineered by americans from the captured alien vehicle. Truth is that B-2 is a german world war II design H-X, stolen by America after the end of war. Those who played Medal of Honor would know.