Piper PA28-236 N129AB accident near Pomona, California

Probable cause

The pilot's spatial disorientation while flying in instrument meteorological conditions that resulted in a loss of control of the airplane. Contributing to the accident was the pilot's lack of recent instrument flying experience.

NTSB analysis

The airplane departed the airport on an instrument-flight-rules clearance. The weather at the airport was 500-foot overcast, with a visibility of 1 mile. The overcast layer was solid up through 3,100 feet mean sea level (msl). The departure instructions were to climb on heading 150 to 1,400 feet msl, then initiate a climbing turn to heading 130, intersect the VOR 164 radial outbound until 9 miles south of the airport, and climb to 4,000 feet. Just after takeoff, at approximately 1,400 feet, the airplane made a climbing turn to 146 degrees and continued to climb on that course for about 1.5 minutes. At 2,500 feet, the airplane started a right-hand turn. The deviation of the airplane’s course prompted the terminal radar approach controller (TRACON) to ask if the pilot had canceled his clearance. The pilot responded in a steady even tone, “Negative, nine alpha bravo still climbing.” Five seconds later the airplane was no longer in radar contact. The radar track depicted the airplane in a climbing right-hand turn in a tightening spiral directly over the accident location. The aircraft wreckage was located on a hillside about 2 miles south of the departure airport and in the vicinity of the last radar return. A review of the pilot’s flight records revealed that he held an instrument rating issued in August 2006, and had logged just two instrument approaches since January 2007, neither within the last 90 days. Additionally, he had accumulated 0.8 hours of simulated instrument time and 0.8 hours of actual instrument time since January 2007. There is no record of the pilot obtaining an instrument proficiency check within the 12 months prior to the accident. The tone of the pilot’s response to TRACON’s radio query implied that he was not aware that the airplane had deviated from the departure clearance and was in a steadily tightening right-hand turn. This lack of awareness could be attributed to spatial disorientation or a distraction away from the primary flight instruments.

Text from the NTSB. Open the NTSB docket for WPR09FA150 for the full record.