An F-22 Raptor stealth fighter crashed today in the high desert of Southern California, while on a test mission from nearby Edwards AFB. A test pilot for Lockheed-Martin, which builds the state-of-the art jet, died in the accident.

Air Force public affairs officers said rescue crews were converged on a site six miles north of the Harbor Dry Lakebed, or about 35 miles northeast of Edwards, after the F-22 went down.

A resident of Palmdale, California told KABC-TV that he heard a sonic boom, and “felt a small earthquake,” that “made the whole house shake” around 10 a.m., Pacific Time, when the F-22 went down. However, experts expressed doubt that the noise heard in Palmdale was related to the crash, which occurred more than 40 miles away.

According to Aviation Week, the F-22 was apparently conducting a “captive weapons carry” at the time of the crash. While the Raptor was accompanied by a chase aircraft, sources tell the magazine that the F-22 was separated from the other jet, and the chase pilot did not see what happened.

In a statement released this evening, Lockheed-Martin identified the pilot as 49-year-old David Cooley. “We are deeply saddened by the loss of David, and our concerns, thoughts and prayers are with his family at this time,” the company said.

At the time of the fatal crash, Cooley was assigned to the F-22 Combined Test Task Force, a joint Air Force and contractor team that conducts Raptor flight testing. Prior to joining Lockheed, Cooley was an Air Force pilot for 21 years.

The Raptor was one of a handful assigned to Edwards’ 412th Test Wing, which conducts, analyzes and reports on all flight and ground testing of aircraft and other weapons systems. Another F-22, assigned to the same unit, crashed at the California base in 2004. The pilot of that jet ejected safely.

While the F-22 has compiled an impressive safety record since joining the Air Force fleet, today’s crash comes at an inopportune time. The USAF is pushing for continued production of the Raptor, hoping to increase the number of aircraft from 183, to at least 240.

At one time, the service hoped to buy more than 700 of the fifth-generation fighters. But escalating costs and budget cuts forced the Air Force to scale back its plans. Defense Secretary Robert Gates and other members of the Obama Administration have proposed ending production by 2012, with a final “buy” of just over 200 aircraft.

After the last F-22 crash in 2004, the Air Force instituted a two-week “stand down” of the Raptor fleet, while technicians inspected the other jets. It is unclear if today’s accident will prompt similar precautions.

An Air Force accident board will investigate today’s mishap.