HISTORY OF FLIGHT On April 22, 2005, about 1500 Pacific daylight time, a Bishop RV6A, N426BB, collided with upsloping mountainous terrain about 4.8 nautical miles (nm) south-southwest of Dulzura, California. The experimental, homebuilt airplane was destroyed, and the private pilot was seriously injured. The airplane was owned and operated by the pilot-builder. Instrument meteorological conditions prevailed in the vicinity of the accident site, which was about 0.5 miles north of the peak of the Otay Mountain, elevation 3,566 feet mean sea (msl). The flight was performed under the provisions of 14 CFR Part 91, and no flight plan had been filed. The flight originated from the Brown Field Municipal Airport, San Diego, California, at 1452. The pilot had commenced his takeoff seconds behind another RV6A, which was flown by an instrument-rated pilot. After taking off, the pilots intended to climb to 7,500 feet msl, intercept Victor Airway 66, and fly in a loose formation to Arizona. Federal Aviation Administration (FAA) radar data indicates that after departing from runway 26R, both airplanes performed right crosswind climbing turns, and they departed the traffic pattern while climbing on the downwind leg. The lead airplane pilot reported that he climbed around scattered to broken clouds, and eventually he climbed on top of the clouds, with over 3 miles forward visibility. At 1456, the Brown Field local controller advised the lead airplane pilot that he could change radio frequencies, and the lead pilot acknowledged the clearance. Thereafter, the lead pilot changed to the previously established air-to-air frequency and asked the pilot in trail "are you with me?" The pilot responded by stating "yes." The lead pilot continued climbing and proceeding in an easterly direction. After a few minutes had elapsed, during which he had not received any additional communications from the pilot in trail, the lead pilot contacted the local controller and indicated his intention to return to the Brown Field. The lead pilot advised the controller that he had lost contact with the pilot in trail. PERSONNEL AND AIRCRAFT INFORMATION The pilot learned to fly in 1967. Acquaintances of the pilot reported that his total flight time was about 1,600 hours, and he had about 900 hours of flying experience in the accident airplane. The pilot was not instrument rated. An examination of the pilot's personal flight record logbook (#4) indicates his total flight time recorded in this logbook was 954.5 hours. Between October 7, 2004, and March 29, 2005, the pilot's logbook only listed flying time in the accident airplane. The listed time was 60.5 hours. The airplane was equipped with a wing leveler. METEOROLOGICAL INFORMATION Rescue personnel who detected the airplane's emergency locator beacon (ELT) and thereafter flew to the crash site reported that, about 1 hour after the accident, clouds were present in the vicinity of the Otay Mountain. Some of the mountainous area in the vicinity of the accident site was partially obscured by clouds. In pertinent part, at 1453, the Brown Field, elevation 526 feet msl, reported the following weather conditions: wind from 260 degrees at 7 knots; visibility 10 statute miles; broken ceiling at 1,600 feet above ground level (agl); overcast at 2,300 feet agl. At 1529, the following weather conditions were reported: wind from 250 degrees at 8 knots; visibility 10 statute miles; scattered clouds at 2,300 feet agl; broken ceiling at 8,000 feet agl. WRECKAGE AND IMPACT INFORMATION Fire department personnel reported to the National Transportation Safety Board investigator that the accident site is located at the following global positioning satellite (GPS) coordinates: 32 degrees 35.3 minutes north latitude by 116 degrees 51.0 minutes west longitude. The site is approximately 6.7 miles east-northeast (069 degrees, magnetic) from the Brown Field. FAA aviation safety inspectors examined the airplane wreckage at the accident site. They reported observing an estimated 150-foot-long ground swath leading to the main wreckage, which was upside down. The FAA inspectors indicated that the fragmentation to the airplane structure, and the crush signatures along with the corresponding ground scar, were consistent with the airplane having cruised into the estimated 15-degree upsloping terrain while in a near wings level flight attitude. The approximate elevation at the initial point of ground impact is 2,770 feet mean sea level. They observed no evidence of a preimpact oil leak on the empennage, and there was no fire. See the FAA inspector's statement for additional information. TESTS AND RESEARCH Radar Data. FAA radar data indicates that at 1458:02, the accident airplane was located at 32 degrees 36.798 minutes north latitude by 116 degrees 55.153 minutes west longitude. This was the airplane's last recorded position. The accident site is located about 3.8 nm east (100 degrees, magnetic) from this location. GPS Data. The airplane was equipped with a Garmin global positioning satellite receiver, model GPSmap 196. It was removed from the wreckage and examined. The receiver was found functional and had aviation database 0504 installed, which according to Garmin was current. The operating system was version 3.60, which was at least 1 year old. The Safety Board investigator, using Garmin's current MapSource program, examined all retained routes, tracks, and waypoints. None of the stored track data was found to be pertinent to the accident site location. The receiver was found with an active goto selected of E95. (E95 is the FAA identifier for the Benson Municipal Airport, reportedly the pilot's ultimate destination.) The last position recorded by the receiver prior to its last shutdown indicated its location was at 32 degrees 35.620 minutes north latitude by 116 degrees 53.207 minutes west longitude. The airplane's GPS elevation was 2,393 feet msl, which was about 600 feet above the underlying terrain. The Safety Board investigator ascertained that the accident site is about 1.9 nm east (087 degrees, magnetic) from this location.