WPR16FA041

The noninstrument-rated pilot's decision to conduct and continue the flight despite forecast and en route instrument meteorological conditions (IMC), which were not conducive to safe operation under visual flight rules. Also causal to the accident was the pilot's decision to accept an instrument flight rules clearance and fly into IMC during cruise flight, which led to his spatial disorientation and a resultant loss of control and an in-flight breakup. Contributing to the accident was the pilot's self-induced pressure to arrive at the destination for a party that night.

The private pilot downloaded official weather briefings onto his tablet computer the night before and again on the morning of the planned cross-country personal flight. The forecast conditions were not conducive to visual flight and included a series of storms passing through the intended flight route, which resulted in instrument meteorological conditions (IMC), high cloud tops, and the potential for icing and mountain obscuration. Despite these forecasts, the low-time, noninstrument-rated private pilot departed with his wife and their three children for the intended vacation, which included a surprise party later that night. According to Federal Aviation Administration radar tracking data, shortly after departure, the flight began to encounter the forecast weather conditions, and the flightpath and altitude began to change as the pilot repeatedly deviated to avoid clouds. Air traffic control (ATC) personnel provided the pilot with regular reports of bands of precipitation and the potential for airframe icing along the intended direction of flight. However, the pilot chose to continue the flight, and the cloud tops ahead continued to rise. The pilot kept climbing the airplane to remain clear of the cloud tops and eventually reached an altitude close to Class A airspace, where an instrument flight rules (IFR) clearance would be required, and close to the airplane's approved operating ceiling of 20,000 ft. The flight continued, but the airplane then began descending, and shortly after, the airplane likely entered the clouds. An air traffic controller then offered the pilot the option to obtain an IFR clearance and continue the flight. Despite his lack of both an instrument rating and his limited experience flying in IMC, the pilot accepted. Radar data indicated that, during this period, the airplane turned abruptly left, directly toward a region of heavy precipitation. Then, shortly after accepting the IFR clearance, and likely while the pilot was distracted from controlling the airplane as he configured the airplane's avionics, the flightpath became erratic. The airplane performed a rapid descending left turn, after which the pilot transmitted a distress call. The flight continued to progress erratically, and the pilot made another distress call, after which the controller provided the pilot vectors to a nearby airport; however, no response was received. Subsequently, an alert notice was issued for the airplane, and the wreckage was located a few hours later. Analysis of the debris field, airplane component damage patterns, and fracture surfaces indicated that both wings and stabilator halves separated from the fuselage in flight due to overstress resulting from excessive air loads. These air loads were likely induced by the pilot during his attempt to regain airplane control, which he lost shortly after the airplane entered the clouds. All persons on board were ejected from the airplane during the breakup sequence and sustained fatal injuries. The reasons for the loss of control were likely the pilot's inability to maintain airplane control in IMC; his spatial disorientation, as evidenced by the erratic flightpath; airframe icing; pitot-static system icing; or some combination thereof. Icing could not be ruled out because the airplane was in visible moisture and flew directly into and toward precipitation just before the diversion. Although the airplane was equipped with an autopilot, variations in heading and altitude throughout major portions of the flight suggested that the pilot was likely hand-flying the airplane. According to one of the airplane's owners, the autopilot was operational. However, the primary autopilot components were destroyed during the accident; thus, its operational status could not be determined. The pilot had planned for the flight to last just over 2 hours and, based on his departure time, would have landed just before sunset. However, because of the weather deviations, the airplane had only reached the half-way point when the accident occurred, with about 30 minutes remaining before sunset. The airplane was only equipped with a supplemental oxygen system sufficient for three persons. However, for more than half of the flight duration, the airplane was operating at altitudes that required all five occupants to be provided with and using oxygen. An oxygen mask was found entangled with the pilot's jacket, and the relative clarity of his communications with air traffic control suggested that he was using supplemental oxygen. Given the pilot was not rated for IFR and did not have adequate oxygen equipment for his family, he may have been reluctant to declare an emergency and request a climb above flight level 180 and into class A airspace, which would likely have taken him into visual meteorological conditions, but instead accepted the IFR clearance at a lower level that did not ensure he could remain clear of clouds. His decision-making under increasingly adverse conditions was likely driven by a desire to get his family to the destination for the scheduled event that evening. Although the pilot's autopsy identified significant coronary artery disease, there was no evidence of an old or new heart attack. Further, the pilot's radio communications and subsequent distress call revealed no evidence to support pilot impairment or incapacitation due to the coronary disease.

Weight and Balance Fueling records provided by a fixed-base operator at San Martin Airport, San Martin, California, revealed that the airplane had been serviced with 59.26 gallons of 100 low-lead aviation fuel from the self-service pump 10 days before the accident. According to the airplane flight logbook, the accident pilot then flew the airplane that day, returning it to San Jose, for a flight time of 0.6 hour. The logbook did not contain any other flight entries until the accident flight. According to one of the airplane's co-owners, the partnership agreement stated that the fuel tanks should be topped off after each flight. The distribution of the airplane contents throughout the debris field prevented an accurate weight and balance assessment, and the airplane's most recent weight and balance records could not be located. However, an estimated weight and balance calculation was conducted. According to the airplane's original Pilot's Operating Handbook (POH) and FAA-approved Airplane Flight Manual, the airplane had a factory basic empty weight of 2,082 lbs and a useful load of 1,518 lbs. The medical examiner reported that the total weight of all occupants was 604 lbs. The baggage and cabin contents recovered from the debris field totaled about 170 lbs. Therefore, assuming a total fuel load of 60 gallons, the airplane would have been about 384 lbs below its maximum gross weight of 3,600 lbs at the time of the accident. Airspeed and Altitude Information The POH, Section 2.3, "Airspeed Limitations," stated that the airplane's never-exceed speed was 189 knots calibrated airspeed (KCAS) and that the maximum structural cruising speed (VNO) was 150 KCAS. The POH noted, "Do not exceed this speed [VNO] except in smooth air and then only with caution." The POH also listed design maneuvering speeds (VA) for gross weights of 3,600 lbs (132 KCAS) and 2,170 lbs (109 KCAS) and noted that full or abrupt control movements should not be made above VA. The POH, Section 2.23, "Operating Limitations Altitude," stated that flight above 20,000 ft was not approved and that flight up to and including 20,000 ft was approved if the aircraft was equipped with oxygen in accordance with Federal Aviation Regulation (FAR) 23.1441 and avionics in accordance with FAR 91 or 135. Airplane Performance Study An airplane performance study was conducted to determine the events leading up to the inflight breakup. The study used radar data, winds aloft information, debris locations and covered the last 22 minutes of flight. An airplane gross weight of 3,600 lbs was used for the study. About 1552, when the airplane began the 90° left turn toward Bakersfield, it was about 14,900 ft. Within 34 seconds, as the air traffic controller was providing the pilot his IFR clearance, the airplane had reached 168 KCAS (above the maximum structural cruising speed). The airspeed then began to decrease, and, about 2 minutes later, the airplane reached 15,500 ft at 145 KCAS and was turning left to the northwest. Interpolation of radar data indicated that the airplane then performed an abrupt left turn from about 300° to 89° during the 4.5 seconds between radar returns and lost about 1,000 ft of altitude. Presuming that the maneuver was conducted in coordinated flight, the turn corresponded to a rate about fifteen times faster than standard and imposed a load factor of about 2.8 g's. The pilot then transmitted the first mayday call, and the airplane continued to descend while tracking generally east and "zig-zagging" to the north and south. The airplane continued to descend during this final period as the airspeed varied from 150 to 90 KCAS and then back to 145 KCAS. The airplane's final radar return at 1556:10 placed it on a 20° track, at 11,200 ft, and almost directly above the north end of the debris field. For most of the last 22 minutes of flight, the airplane's airspeed was at or above the 132 KCAS maneuvering speed. Airspace Class A airspace is generally classified as the airspace from 18,000 ft msl up to and including flight level 600. Additionally, CFR 91.135 states that unless otherwise authorized, all operation in Class A airspace is conducted under instrument flight rules. Supplemental Oxygen Requirements Title 14 CFR 91.211 states the following: No person may operate a civil aircraft of U.S. registry (1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration; (2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes; and (3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant of the aircraft is provided with supplemental oxygen. Radar data indicated that for the last 51 minutes of flight before the mayday call diversion, the airplane flew at mode C reported altitudes varying between 15,075 and 17,750 ft. The Kern County Sheriff-Coroner's Office performed an autopsy of the pilot. The cause of death was reported as "multiple blunt force trauma." The report noted that the pilot weighed 190 lbs. Evidence of coronary artery disease was identified; no other significant natural disease was found. The FAA's Bioaeronautical Sciences Research Laboratory conducted toxicological tests on the pilot specimens. The testing was negative for carbon monoxide, ingested alcohol, and any screened drug substance. The pilot filed a VFR flight plan and obtained an electronic weather briefing via the CSC direct user access terminal service (DUATS) using Garmin Pilot software installed on a tablet computer. Transaction data provided by CSC DUATS revealed that the pilot initiated the briefing at 2202 the night before the accident flight and initiated another briefing at 0653 on the morning of the flight. The pilot did not call Lockheed Martin Flight Service for a telephone weather briefing nor did he activate the VFR flight plan once airborne. The tablet computer was recovered at the accident site, and although its screen was damaged, the 0653 weather briefing was still loaded, along with the flight plan and flight route summary. The flight summary documented a total distance of 386.8 nautical miles with an average groundspeed of 187 knots. The filed flight route indicated a departure from San Jose at 1400 with waypoints of Paso Robles Municipal Airport, Paso Robles, California, and Meadows Field Airport, Bakersfield, California, at an altitude of 13,500 ft. The filed en route flight time was 2 hours 4 minutes, and the flight plan indicated 4 hours 28 minutes of fuel onboard, and a true airspeed of 165 knots. The airplane was not equipped with a weather radar system nor a data uplink system that would have allowed weather to be updated in flight to either the Garmin MX20 or the Garmin Pilot software. Additionally, although the version of Garmin Pilot software used by the pilot was GPS enabled, it did not have the capability to log flight track data. Synoptic Conditions The National Weather Service (NWS) Surface Analysis Chart for 1600 depicted a low pressure center immediately south of the accident site. From this low-pressure center, a cold front extended south, then southwest over the Pacific Ocean. Extending east from the low pressure center was a short stationary front with a cold front extending northeast and east. NEXRAD area imagery for the same period depicted light-to-moderate values of reflectivity over much of the accident region. Area Forecast An area forecast that included the central portion of the state of California was issued at 1245 by the Aviation Weather Center in Kansas City, Missouri. The area forecast for the San Joaquin Valley for the accident time inc