History of Flight
On April 28, 2017, at about 2348 central daylight time, a Pilatus PC-12 airplane, registration N933DC, operated by Rico Aviation LLC under 14 CFR Part 135 as an air ambulance flight, impacted terrain near Rick Husband Amarillo International Airport (AMA), Texas. The flight was originating at AMA en route to Clovis Municipal Airport, New Mexico, for a patient transport mission. Instrument meteorological conditions (IMC) prevailed, and the flight operated on an instrument flight rules (IFR) flight plan.
The pilot had received an ATC clearance earlier and contacted ground control for taxi to runway 4. After takeoff, the local controller observed a transponder code discrepancy (the airplane initially transmitted code 4254, from a previous flight, instead of the assigned 4261). The controller instructed the pilot to reset the transponder, which he did. The pilot then contacted departure control at 2346:54, reporting at 6,000 ft msl. At 2348:12, the departure controller advised the pilot that the transponder signal was lost; no response was received. Multiple subsequent transmissions went unanswered. A local controller reported observing a fireball and a potential crash. Surveillance video from a nearby truck stop captured lights from the airplane followed by an explosion, showing the airplane descending at about a 45° angle to ground impact.
Personnel Information
The pilot-in-command (PIC), age 57, had been employed by Rico Aviation since November 2016. He underwent initial PC-12 flight training between October 26 and 28, 2016, conducted by ACFT Services LLC, and received additional training from the company’s director of operations (DO) and chief pilot. None of those who flew with him reported concerns about his flying skills. Training records indicated satisfactory completion of maneuvers including stalls and unusual attitude recovery.
The pilot had flown 28 hours in the preceding 90 days and 115 hours in the last year, 73 of which were in the PC-12. His IFR flight time in the preceding 90 days totaled 4.2 hours, with 1.4 hours at night. He had accumulated 2.6 hours of night IFR time and 5.9 hours total IFR time since his last instrument proficiency check on December 21, 2016.
The pilot worked night shifts (1900–0800) from April 25 to April 28, logging 2 hours across those shifts. He rotated between the Amarillo and Dalhart bases. His wife reported that he had no issues adapting to the overnight schedule and that he would sleep during the day when on duty overnight. She noted nothing unusual in their communications during the three days before the accident.
Aircraft Information
The airplane was a nine-passenger, single-engine turboprop configured as an air ambulance with pilot and copilot seats, four cabin seats, and a patient bed. At the last recorded flight log, total time was 4,466.9 hours and 3,769 cycles.
Maintenance records documented two autopilot discrepancies. On March 2, 2017, the autopilot computer was replaced due to disconnecting on approaches (part number 065-0064-15, serial number 2175 replaced with modified unit X1898). On April 26, 2017, a pilot reported autopilot disconnects during climb and cruise; the autopilot trim adapter was replaced (part number 065-00164-0100, serial number 1745 replaced with tested unit 1794). The system ops check was satisfactory. No other discrepancies with the electronic attitude director indicator (EADI) or attitude and heading reference system (AHRS) were noted.
The PC-12’s automatic flight control system is a Honeywell KFC-325 digital system providing 3-axis control. The autopilot requires a successful preflight test (PFT) before engagement. Disengagement can occur manually or automatically due to various conditions, including exceeding roll rates above 10° per second or pitch rates above 5° per second.
Meteorological Information
The pilot obtained a ForeFlight weather briefing at 2303 and filed an IFR flight plan. Archived weather data for AMA at 2353 reported wind from 360° at 21 knots gusting to 28 knots, visibility 10 statute miles or more, ceiling broken at 700 ft agl, overcast at 1,200 ft agl, temperature 7°C, dew point 7°C, altimeter 29.78 inHg. Remarks included peak wind 32 knots from 360° at 2326, lightning more than 10 miles west, rain from 2314 to 2325, and variable ceiling between 500 and 900 ft agl.
Radar data indicated light reflectivity near the accident location. Veering wind was identified in the lowest 10,000 ft msl, with a wind shear zone between 2,500 and 3,500 ft msl showing northerly surface wind and 40–60 knot southerly wind above 4,000 ft. A high-resolution rapid refresh model sounding at 0000 on April 29 indicated a temperature inversion between 6,200 and 7,800 ft msl, a freezing level near 13,000 ft, and a layer of significant turbulence between about 5,500 and 12,600 ft msl. Relative humidity was above 90% from near the surface to about 10,000 ft.
At 2145, an AIRMET SIERRA was issued for IFR conditions and precipitation/mist below 10,000 ft msl covering the accident area. No AIRMETs for turbulence or low-level wind shear were active below 10,000 ft at the accident time. An AIRMET TANGO for moderate turbulence between 10,000 ft msl and FL180 was active. A convective SIGMET was issued at 2255 for an area close to the accident location; such SIGMETs imply severe or greater turbulence, severe icing, and low-level wind shear.