Inflight Breakup Near Lake Wales, Florida (N950KA)

Accident Overview and Flight Details The aircraft, registered to and operated by Roadside Ventures, LLC, departed from controlled flight and subsequently broke up in flight near Lake Wales, Florida. The accident occurred under instrument meteorological conditions. An instrument flight rules (IFR) flight plan had been filed for the 14 Code of Federal Regulations (CFR) Part 91 personal flight from St. Lucie County International Airport (FPR) in Fort Pierce, Florida, to Freeman Field Airport (3JC) in Junction City, Kansas. The flight departed FPR at approximately 1205. The aircraft sustained substantial damage, and the private pilot and five passengers were fatally injured. ## Air Traffic Control Communications After departure, the aircraft proceeded in a west-northwesterly direction while climbing. Air traffic control communications were transferred to Miami Air Route Traffic Control Center (Miami ARTCC). The pilot maintained contact with various sectors of the facility from 1206:41 until the last recorded communication at 1233:16. Approximately six minutes after takeoff, the pilot was advised by the Miami ARTCC Stoop Sector radar controller of an area of moderate to heavy precipitation located 12 to 2 o'clock, 15 miles ahead of the aircraft's position. The returns were reported to be 30 miles in diameter. The pilot inquired whether he needed to circumnavigate the weather. The controller replied that deviations north of course were approved and that the pilot could proceed direct to LAL when able, which the pilot acknowledged. A trainee controller and a controller providing oversight discussed off frequency that a deviation to the south would be preferable. The controller then questioned the pilot about his route, and after the pilot replied, the controller advised that deviations south of course were approved, which the pilot acknowledged. ## Final Flight Phase The flight continued in a generally west-northwesterly direction, or approximately 290 degrees. At 1230:11, while at flight level (FL) 235, the controller cleared the flight to FL260, which the pilot acknowledged. At 1232:26, the aircraft's central advisory and warning system (CAWS) recorded that the pusher system entered “ice mode,” indicating the pilot had selected propeller heat on and the inertial separator open. At that time, the engine information system (EIS) recorded the aircraft at 24,668 feet pressure altitude, 110 knots indicated airspeed (KIAS), and an outside air temperature of minus 11 degrees Celsius. At 1232:36, the Miami ARTCC Avon Sector radar controller advised the pilot of a large area of precipitation northwest of Lakeland, with moderate, heavy, and extreme echoes in the northwest. The controller asked the pilot to look at the weather and advise what direction he needed to deviate, then suggested a deviation right of course until north of the adverse weather. The pilot agreed, and the controller asked what heading from his position would keep the aircraft clear. The pilot responded at 1233:04 with 320 degrees. At 1233:08, the controller cleared the pilot to fly heading 320 degrees or to deviate right of course when necessary, and to proceed direct to Seminole when able, which the pilot acknowledged at 1233:16. No further recorded communication from the pilot with Miami ARTCC followed. ## Radar Data and Performance Study Radar data showed that between 1233:08 and 1233:26, the aircraft flew on a heading of approximately 290 degrees and climbed from FL250 to FL251. During the same period, the EIS recorded the aircraft at either 109 or 110 KIAS, with an outside air temperature of minus 12 degrees Celsius. Radar data indicated that between 1233:26 and 1233:31, the aircraft climbed to FL252, the highest recorded altitude from secondary radar returns. At 1233:30, while at slightly less than 25 degrees of right bank based on the NTSB Radar Performance Study, 109 KIAS, 25,188 feet, and a total air temperature of minus 12 degrees Celsius based on CAWS data, autopilot disengagement occurred. This was recorded on the CAWS three seconds later. The NTSB Performance Study indicates that based on radar returns between 1233:30 and 1233:40, the bank angle increased from less than approximately 25 degrees to 50 degrees, while radar data for the approximate same time period indicates the aircraft descended to FL249. The NTSB Performance Study indicates that based on radar returns between 1233:40 and 1234:00, the bank angle increased from 50 degrees to approximately 100 degrees, while radar data indicates that for the approximate same time frames, the aircraft descended from FL249 to FL226. The right descending turn continued, and between 1233:59 and 1234:12, the aircraft descended from 22,600 to 16,700 feet, with a change to a southerly heading noted. The NTSB Performance Study indicates that the maximum positive load factor of 4.6 occurred at 1234:08, while the NTSB Electronic Device Factual Report indicates that the maximum recorded airspeed value of 338 knots recorded by the EIS occurred at 1234:14. The next recorded airspeed value one second later was noted to be zero. Simultaneous to the zero airspeed, a near level altitude of 15,292 feet was noted. Between 1234:22 and 1234:40, radar data indicated a change in direction to the northeast, and the aircraft descended from 13,300 to 9,900 feet. The aircraft continued generally in a northeasterly direction, and between 1234:40 and 1235:40 (last secondary radar return), the aircraft descended from 9,900 to 800 feet. The last secondary radar return was located at 27 degrees 49.35 minutes North latitude and 081 degrees 28.6332 minutes West longitude. ## Post-Accident Communications and Witness Account At 1235:27, the controller asked the pilot to report his altitude, but there was no reply. The controller enlisted the aid of the flight crew of another aircraft to attempt to establish contact with the pilot on the current frequency and also 121.5 MHz. The flight crew attempted on both frequencies but received no reply. At 1236:30, the pilot of a nearby aircraft advised the controller that he was picking up an emergency locator transmitter (ELT) signal. The pilot of that aircraft advised the controller at 1237:19 that, “right before we heard that ELT we heard a mayday mayday.” The controller inquired whether the pilot had heard the mayday on the current frequency or 121.5 MHz, to which he replied that he was not sure because he was monitoring both frequencies. The controller inquired with the flight crews of other aircraft if they heard the mayday call on the frequency, and the response was negative, though they did report hearing the ELT on 121.5 MHz. The controller verified with the flight crews that were monitoring 121.5 MHz whether they heard the mayday call on that frequency, and they advised they did not. A witness located about 1.5 nautical miles south-southwest from the crash site reported that on the date and time of the accident, he was inside his house and first heard a sound he attributed to a propeller feathering or later described as flutter of a flight control surface. The sound lasted 3 to 4 cycles of a whooshing high to low sound, followed by a sound he described as an energy release. He was clear the sound he heard was not an explosion, but more like mechanical fracture of parts. He ran outside and first saw the aircraft below the clouds (ceiling was estimated to be 10,000 feet). He noted by silhouette that parts of the aircraft were missing, but he did not see any parts separate from the aircraft during the time he saw it. At that time, it was not raining at his location. He went inside his house, got a digital camera, then ran back outside to his pool deck and videotaped the descent. He reported the aircraft was in a spin but could not recall the direction. The engine sound was consistent the whole time; there was no revving; he reported t