A Twin Commander taking off full length from 5,000-foot Runway 12R at North Las Vegas Airport for a VFR surveillance flight appeared never to get out of ground effect before it hit terrain about 600 feet southeast of the runway. The twin recip was destroyed and the pilot and two passengers were injured in the July 21 accident. Witnesses told the NTSB that they saw the airplane airborne but not climbing. “The airplane continued down the runway in a nose-up attitude and remained in ground effect” until it hit the terrain, the NTSB said. Density altitude at the time of the accident (about 5 p.m. local) was 5,878 feet msl and the air temperature was reported at about 105 degrees F. Wind was variable at three knots. The flaps were measured and indicated 30 degrees. Normal flap setting for takeoff is 10 degrees, according to the airplane flight manual. Commander Northwest of Anchorage, Alaska, was operating the 1964 airplane, N7UP, for the U.S. Forest Service under Part 91 as a public-use aircraft.