ANC19FA012

A loss of control for reasons that could not be determined based on the available information.

The pilot of the medical transport flight had been cleared by the air traffic controller for the instrument approach and told by ATC to change to the advisory frequency, which the pilot acknowledged. After crossing the initial approach fix on the RNAV approach, the airplane began a gradual descent and continued northeast towards the intermediate fix. Before reaching the intermediate fix, the airplane entered a right turn and began a rapid descent, losing about 2,575 ft of altitude in 14 seconds; radar returns were then lost. A witness at the destination airport, who was scheduled to meet the accident airplane, observed the pilot-controlled runway lights illuminate. When the airplane failed to arrive, she contacted the company to inquire about the overdue airplane. The following day, debris was found floating on the surface of the ocean. About 48 days later, after an extensive underwater search, the heavily fragmented wreckage was located on the ocean floor at a depth of about 500 ft.  A postaccident examination of the engines revealed contact signatures consistent with the engines developing power at the time of impact and no evidence of mechanical malfunctions or failures that would have precluded normal operation. A postaccident examination of the airframe revealed about a 10° asymmetric flap condition; however, significant impact damage was present to the flap actuator flex drive cables and flap actuators, indicating the flap actuator measurements were likely not a reliable source of preimpact flap settings. In addition, it is unlikely that a 10° asymmetric flap condition would result in a loss of control. The airplane was equipped with a total of 5 seats and 5 restraints. Of the three restraints recovered, none were buckled. The unbuckled restraints could suggest an emergency that required crewmembers to be up and moving about the cabin; however, the reason for the unbuckled restraints could not be confirmed. While the known circumstances of the accident are consistent with a loss of control event, the factual information available was limited because the wreckage in its entirety was not recovered, the CVR recording did not contain the accident flight, no non-volatile memory was recovered from the accident airplane, and no autopsy or toxicology of the pilot could be performed; therefore, the reason for the loss of control could not be determined. Due to the limited factual information that was available, without a working CVR there is little we know about this accident.

According to the operator's training records, the pilot completed initial training at Guardian Flight (the accident operator) and was eligible for duty as a pilot-in-command in a Raytheon Aircraft Company B200 aircraft on May 15, 2015. According to his personal logbook, he was hired with a total flight time of about 16,878 hours, 1,937.9 hours of actual IFR, 1,371.5 hours of simulated IFR, 3,720.2 hours of night time, and 12,559.2 hours cross country. In addition, he had accumulated about 1,644.5 hours in the accident airplane make and model since starting with the company. His most recent airman competency/proficiency check, which was administered by a company check airman, was completed on October 11, 2018. The pilot's flight and duty records revealed that on January 26, his duty day started at 0600 and ended at 1800; and he did not fly. On January 27, his duty day started at 0600 and ended at 1830; and he flew 2.4 hrs. On January 28, his duty day started at 0600 and ended at 1800; and he flew 1.5 hrs. On January 29, the day of the accident, the pilot's duty start time was not recorded; however, Guardian Flight indicated his duty day started at 0600 and he flew about 2.5 hrs prior to the accident flight.  The Raytheon Aircraft Company B200 was a six seat, low wing, multiengine airplane manufactured in 2000. The airplane was equipped with two tandem LifePort stretcher systems and Aerosleds that had been installed in conformance with LifePort supplemental type certificate No. SA00273WI. The aircraft was configured with two flight crew seats in the cockpit. The LifePort tandem stretcher systems were installed on the right side of the cabin portion of the airplane, and three passenger seats were on the left side of the cabin portion of the airplane, two forward facing and one aft facing. The operator maintained the airplane in accordance with the Beechcraft Super King Air 200 Series Maintenance Manual P/N 101-590010-19, issued December 21, 1973, and P/N 101-590010-19D6 revised May 1, 2017.   To date, the remains of the pilot and the two additional crewmembers have not been located; therefore, no pathological or toxicology information exists. At the time of the pilot's last medical examination, no concerns were reported by the pilot and no significant issues were identified by the medical examiner. The airplane impacted the ocean waters of Frederick Sound and was located with the assistance of a remote operated vehicle (ROV) on March 19, 2019, at a depth of about 500 ft. A cone shape debris field spanned about 1,650 ft on a bearing of 45º, with the lighter debris farther northeast due to the ocean current. (see figure 3.) Figure 3 - Debris field figure produced by TerraSond courtesy of Alaska Claims Services, Inc. On March 22 through March 26, 2019, recovery crews, with the assistance of a ROV, recovered most of the airplane's major components from the ocean floor and transported them to Juneau, Alaska. Items that were not found or recovered included but were not limited to, the right aileron, portions of both left and right wings, and portions of both left and right elevators. The cockpit and instrument panel exhibited extensive impact damage. The floor of the cabin area of the fuselage separated from the aircraft structure and none of the cockpit or passenger seats were located within the airplane. The left wing was fragmented but remained relatively intact along its span. The outboard section of the left wing, which included most of the left aileron, separated from the wing structure but remained attached by the twisted aileron and aileron trim cables. The left inboard flap actuator was extended 2.55 inches, which equated to about 0°-10° extended. The left inboard flap actuator flex drive cable was fractured at the actuator. The left outboard flap actuator was extended 2.95 inches, which equated to about 10° extended. The left outboard flap actuator flex drive cable was partially separated, stretched and the cable strands were separated near the actuator. The right wing was heavily fragmented and separated from the fuselage into three main sections. The inboard section included the inboard flap and aft spar section from the wing root to the right engine nacelle. The center section included the right main landing gear, the aft portion of the right engine nacelle, and about 8 ft of the wing. The outboard section consisted of about a 10 ft by 3 ft section of the wing skin with the fractured right aileron bellcrank attached. The right aileron was not recovered. The right inboard flap actuator was extended 2.10 inches, which equated to fully retracted. The right inboard flap actuator flex drive cable attachment fitting was fractured and separated at the actuator. The outboard right flap actuator was extended 1.70 inches, which also equated to fully retracted. The outboard right flap actuator flex drive cable remained attached to the actuator. The vertical stabilizer separated and exhibited leading edge impact damage. The rudder remained attached to its attach points and was relatively undamaged. The right horizontal stabilizer, right elevator, and about a 3-ft section of the left elevator separated from the vertical stabilizer. About 2 ft of the outboard right elevator and the remainder of the left elevator were not recovered. The cockpit flight crew seats were recovered, and both seat belt restraints were found unbuckled. One passenger seat was recovered, and the seat belt restraint was found unbuckled. The base of a second passenger seat was recovered; however, the seat back and seat belt restraint were not recovered. All recovered seats exhibited impact damage. One rear passenger seat was not recovered. Both engine external cases exhibited no signs of fire damage or thermal distress. No anomalies, contamination, or evidence of malfunction were found in any of the engine accessories. The engines displayed contact signatures to their internal components characteristic of the engines developing power at the time of impact. The examination of the engines revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Both the left and right propeller hubs fractured and separated at the propeller shaft. The left propeller blades exhibited torsional twisting, two blades exhibited leading edge gouging, and one blade was missing its tip. All four of the right propeller blades exhibited torsional twisting and leading-edge gouging, and one blade was missing a portion of the propeller tip. Control continuity could not be established due to numerous fractures in the system and missing cabling and flight control surfaces. On January 29, 2019, about 1811 Alaska standard time, a Raytheon Aircraft Company B200 airplane, N13LY, was destroyed when it was involved in an accident in Kake, Alaska. The pilot, flight paramedic, and flight nurse were presumed fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 air ambulance flight. The flight, operated by Guardian Flight LLC, departed Ted Stevens Anchorage International Airport (ANC), Anchorage, Alaska at 1604, on an instrument flight rules (IFR) flight plan, destined for the Kake Airport (AFE), Kake, Alaska. A review of archived voice communication information from the Federal Aviation Administration (FAA) indicated that, at 1806:07, the radar controller cleared the pilot for the radio navigation (RNAV) runway 11 approach to AFE, which the pilot confirmed. At 1807:45, the controller advised the pilot to change frequency, which the pilot also confirmed. There were no further communications with the accident flight. A review of archived FAA radar and ADS-B data revealed that the accident airplane crossed the CEMGA waypoint on the RNAV runway 11 approach at an altitude of about 7,000 ft above mean sea level (msl), then turned northeast and crossed the ZOLKO initial approach fix about 5,000 ft