WPR11FA173

The pilot's decision to conduct the flight into a region of reported moderate to severe turbulence and icing conditions, followed by a loss of airplane control and an aerodynamic spin from which the pilot did not recover.

About 4 hours before the pilot's planned first leg of her return flight home, AIRMETs for instrument flight rules (IFR) and mountain obscuration conditions, moderate turbulence, and moderate icing were issued for the flight track region and timeframe. About 1 hour before the flight, the Federal Aviation Administration (FAA) issued a center weather advisory (CWA) that warned of moderate-to-severe turbulence. There were no records that the pilot obtained a formal weather briefing. According to the pilot's husband, the pilot typically obtained preflight weather information from "aviationweather.gov," but the website does not retain records of user access. A friend of the pilot reported that the pilot was aware that "a storm was coming" into southern California on the day she was leaving, but the friend was unaware of the pilot's specific pre-flight activities or preparations. The investigation was unable to determine whether or how the pilot obtained weather information regarding her planned flight. About 5 minutes after departure on the IFR flight, a second CWA for moderate to severe turbulence for the flight track region and timeframe was issued. The flight proceeded uneventfully until an air traffic controller advised the pilot of a report of light rime icing at her altitude. The controller then broadcast an all-aircraft advisory regarding the issuance (but not content) of the second CWA and instructed pilots to contact flight service for further information. It could not be determined whether the pilot obtained any specific information regarding the CWA, but she did not request to go off frequency to contact flight service. However, she requested a higher altitude in an apparent effort to avoid the reported rime icing. About 2 minutes later, the flight was cleared to 15,000 feet, and several minutes after that, the pilot reported breaking out of the clouds at 13,300 feet. Later, an air traffic controller advised the pilot of a re-route, and she reported that she had encountered moderate turbulence at 15,000 feet. About 3 minutes after that, radar data indicated that the airplane was descending at nearly 12,000 feet per minute and, very shortly thereafter, the airplane was lost from air traffic control radio and radar contact. Several ground eyewitnesses reported observing the airplane in a spin and in a vertical trajectory toward the ground, in an area where the local ceiling was about 12,000 feet above ground level. Although the airplane was substantially damaged by postcrash fire, the evidence indicated that the airplane impacted the ground in an aerodynamic spin. The investigation was unable to determine the specific reasons for the loss of control and resulting aerodynamic spin. Postaccident examination of the engine, propeller, and airframe did not reveal any preexisting mechanical deficiencies or failures that would have precluded normal operation or continued flight. The airplane aerodynamic configuration and weight distribution were significantly modified via several supplemental type certificates (STCs) relative to the original FAA-certificated configuration. Neither the FAA nor any of the STC holders evaluated the individual or combined effects of the STC changes on the airplane's spin susceptibility, characteristics, or recovery capability. Evaluation of the mass properties of the modified airplane indicated that it would be more resistant to spin recovery than it would be as originally configured. However, the investigation was unable to determine if this played a role in the pilot’s inability to recover from the aerodynamic spin. On May 24, 2012, the NTSB issued Safety Recommendations A-12-21 through -23 to the FAA to address the potential adverse effects on an airplane’s performance and structure if it has multiple STCs that are not properly analyzed for compatibility. Toxicological testing by the FAA Civil Aeronautical Medical Institute detected Nortriptyline in the pilot's liver. This is a prescription antidepressant used in the treatment of major depression and for certain chronic pain conditions; it is not normally used for intermittent pain. The pilot did not report the medication during her FAA medical certification examination or on her medical certificate application; pilots taking this medication are not eligible for FAA medical certification. A warning associated with this medication stated that it may impair mental and/or physical ability required for the performance of potentially hazardous tasks. However, the degree to which the pilot may have been impaired from the medication could not be determined.

HISTORY OF FLIGHT On March 20, 2011, about 1234 Pacific daylight time, a Cessna P210N Silver Eagle, N50MC, was substantially damaged when it departed from cruise flight and impacted rocky desert terrain about 2 miles south of Barstow-Daggett Airport (DAG), Daggett, California. The certificated private pilot/co-owner and her two passengers were fatally injured. The personal flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91, and was operating on an instrument flight rules (IFR) flight plan from John Wayne Airport-Orange County (SNA), Santa Ana, California, to Henderson Executive Airport (HND), Las Vegas, Nevada. Instrument meteorological conditions existed for portions of the flight route and altitudes. According to the husband of the pilot, they co-owned the airplane, and they lived and based the airplane in Truckee, California. A few days before the accident, the pilot flew herself and their two children to SNA to visit friends. The accident flight was the first leg of the return trip to Truckee; the pilot had planned the stop at HND as another personal visit. About 0700 on the morning of the accident, the fixed base operator (FBO) at SNA topped off the main fuel tanks of the airplane, in accordance with the pilot's request. Later that morning, the FBO shuttle van picked up the pilot and children at the main terminal of SNA, and stopped at a local fast food restaurant to obtain meals for the children, before continuing to the FBO. According to the driver of the shuttle, they arrived at the FBO about 1100. The pilot informed the FBO personnel that she had to "check the weather" and take care of other "paperwork" before she could be taken to the airplane, which was parked remotely from the FBO office. At least one FBO employee observed the pilot at the computer in the FBO pilot lounge/computer room. After that, the pilot, her children, and their luggage were driven to the airplane. The driver only observed the initial portion of the loading, and no one from the FBO observed the preflight inspection or departure of the airplane. The driver reported that the pilot was not talkative, and that she told her coworkers that the pilot seemed "kind of sad." According to Federal Aviation Administration (FAA) air traffic control (ATC) information, the airplane departed SNA about noon. After departure from SNA, the flight was handled by five different SoCal TRACON (TRAffic CONtrol) sectors/controllers. While climbing through about 9,000 feet above mean sea level (msl) for 11,000 feet, the pilot was advised that there were reports of light rime icing at 11,000 feet, about 10 miles ahead of her. She then requested a higher altitude, and was advised that "the next sector" was "working" on it. About 1217, the flight was handed off to Joshua Approach, and was cleared from 11,000 feet to its cruise altitude of 15,000 feet. Shortly thereafter, the flight was handed off to Los Angeles Air Route Traffic Control Center (ARTCC, referred to as "LA Center"). About 1219, while in communication with the first sector of LA Center, the pilot was advised that she was in an area of moderate precipitation that extended about 10 miles ahead of her. About 1224, the pilot advised that she "broke out" of the clouds at 13,300 feet. About 1229, after she was switched to the next LA Center sector, the pilot was advised that ATC had amended her route, and was asked whether she was ready to copy it. She acknowledged the transmission with "go ahead," and the controller issued the revised routing. After a silence of about 16 seconds, the controller asked if the pilot copied the transmission, and the pilot responded "stand by." About 45 seconds later, the pilot advised that she had encountered moderate turbulence, but was now ready to copy. The controller reissued the revised clearance, the pilot read it back, and that was followed by the controller's query to confirm that the pilot reported moderate turbulence, which she did. About 2 minutes 15 seconds after that, a partial and final transmission was received from the airplane, and ATC lost radar contact with the airplane shortly thereafter. Several ground-based eyewitnesses in the vicinity of DAG reported that their attention was initially drawn to the airplane by the varying sound of the engine. They reported that they observed the airplane "spiraling" or "spinning" in a vertical trajectory towards the ground, and that they then observed the resulting explosion, fire, and smoke. The first 911 telephone call was received from an eyewitness at 1234. First responders were only able to access the accident site on foot or by all-terrain vehicles. Firefighting vehicles were unable to access the site due to the terrain. PERSONNEL INFORMATION Pilot FAA records indicated that the pilot held a private pilot certificate with airplane single-engine and instrument-airplane ratings. On her May 2006 application for an FAA first-class medical certificate, the pilot reported that her flight experience included 290 total hours, and 0 (zero) hours in the 6 months prior to the medical examination. On that application, she reported that she was not taking any medications, and had been hospitalized for two childbirths and one minor surgery. No significant pilot medical issues were identified by the aviation medical examiner (AME) who performed that examination. In September 2010, the pilot reported a total flight experience of about 930 hours on her airplane insurance application form. Her most recent flight review was completed in the accident airplane in February 2011. The pilot's personal flight logbook was not recovered; it was presumed lost in the post-impact fire. Her husband estimated that at the time of the accident, the pilot had about 1,000 hours of total flight experience, including about 400 hours in the accident airplane make and model, and about 450 hours of IFR experience. He did not estimate her IFR time in the accident airplane make and model. He stated that they were both pursuing their commercial pilot certificates, and that due to her recent training and flight activity, the pilot was "never more competent and comfortable in the airplane" than she was in the few weeks preceding the accident flight. According to the husband, the pilot typically hand-flew the airplane for about 10 minutes on each trip; most of the time during any flight the autopilot would be engaged. He said she typically turned it on shortly after takeoff for the climb out, and typically before entering IMC. She was well versed in the programming and usage of the airplane's autoflight capabilities. Prior to departure, the pilot would program the Garmin 530 with the planned flight route, and the airplane would then fly the programmed route/profile. Any in-flight ATC-specified changes would be input into the Garmin 530 by the pilot as she became aware of them. She would hand fly the airplane in "heavy turbulence," and she took turbulence "very, very seriously." Both the pilot and her husband avoided icing conditions as much as possible, and she would not hesitate to mention icing if she was encountering it, and/or request ATC assistance/clearance to escape it. The husband stated that 15,000 feet was a typical altitude for short trips. They typically seated the children in the aft (5 and 6) seats. They often removed one or both middle (3 and 4) seats; for this trip one of those seats was removed. The children did not use car seats in the airplane. He stated that the pilot was "very comfortable" flying with the children and no other pilot, since they complied with her need to have little or no interference when she requested or required it. The children did not like using headsets, but headsets were available for them, and the children occasionally used them. The husband reported that neither the pilot nor the children had any known or recent medical issues that could have impacted the flight, and