The twin-engine Sabreliner jet that collided Sunday with a single-engine Cessna over Otay Mesa in San Diego County was returning to Brown Field after completing a test of a radar system for the Navy, officials said Monday.
Four people aboard the Sabreliner and one aboard the Cessna 172 were killed. There were no survivors.
Killed aboard the Sabreliner were three employees of defense contractor BAE Systems and a contractor working for BAE, the company said.
The three employees were Carlos Palos, John Kovach and Jeff Percy, all of whom lived in the Mojave area of Kern County, the company said. The name of the contractor was not released. Nor was the name of the Cessna pilot.
The crash is under investigation by the National Transportation Safety Board. No cause has been given, officials said.
Debris from the mid-air collision was spread over a wide area, although not, as previously reported, in the San Diego National Wildlife Refuge.
The wreckage caused a 2-acre brushfire near California 125 that was quickly extinguished. No structures were damaged or threatened.
Both planes were attempting to land at Brown Field Municipal Airport.
The BAE employees and the contractor aboard the Sabreliner had completed a test of a radar system and were returning to Brown Field, according to a spokeswoman for the Naval Air Warfare Center Weapons Division.
Brown Field is located 1.5 miles north of the Mexican border and 13 miles southeast of downtown San Diego.
"We are committed to supporting investigators as they work to understand how this collision occured," BAE said in a statement.