Piper PA-24-250 N7690P accident near San Diego, California

Probable cause

The pilot's failure to maintain control during an en route cruise descent through multiple cloud layers, resulting in an in-flight breakup.

NTSB analysis

During the pilot's preflight weather briefing for the cross-country flight, he was informed that while a portion of his anticipated hour-long flight could likely be flown under visual flight rules, instrument meteorological conditions, including multiple cloud layers, could be expected approaching his destination. The destination area was covered by a marine cloud layer, with cloud tops of 5,500 feet. En route, the pilot cruised at 7,000 feet. Initially, all air traffic control (ATC) communications with the pilot were routine. An airport located about 6 miles from the accident site reported a broken sky condition at 2,500 and 3,100 feet, and an overcast sky condition at 4,800 feet. As the pilot entered this area, located about 29 miles north of his destination, he informed the terminal radar approach controller that he was descending from 6,200 to 4,000 feet msl. A radar controller acknowledged the pilot's statement. Two and one-quarter minutes later the radar controller instructed the pilot to descend to 2,600 feet, and "keep your speed up." About 5 seconds later, the pilot responded "two thous." The remainder of the pilot's transmission was either interrupted or not recorded, and there were no further communications with the pilot. A review of the recorded radar data and the wreckage distribution evidence indicated that the airplane broke apart after entering instrument meteorological conditions. The structural failure occurred while the airplane was descending at 6,000 feet per minute and in a clockwise turn. The subsequent examination of the airplane revealed that both wings failed in an upward (positive G) direction, consistent with a pilot-induced structural overload. Thereafter, a portion of the right wing impacted the stabilator's right side, which caused it to separate from the airplane. No evidence of any preexisting structural weakness was found during the examination of the heavily fire-damaged main wreckage.

Text from the NTSB. Open the NTSB docket for WPR09FA192 for the full record.