History of Flight
On December 14, 2012, at approximately 1805 central standard time, a Beechcraft E-90 King Air, registration N67PS, impacted terrain following an inflight breakup near Amarillo, Texas. The commercial-rated pilot and one passenger were fatally injured, and the airplane sustained substantial damage. The aircraft was registered to O'Neal Aviation LLC, Colorado Springs, Colorado, and operated by a private individual. Instrument meteorological conditions prevailed, and an instrument flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight departed from Rick Husband International Airport (KAMA), Amarillo, Texas, around 1750, en route to Fort Worth Meacham Airport (KFTW), Fort Worth, Texas.
Air traffic control communications and radar data indicated that the controller transferred the airplane from AMA departure to Albuquerque Air Route Traffic Control Center (ARTCC). The ARTCC controller cleared the airplane to flight level 210 and authorized a deviation east of the route for weather and traffic avoidance. Shortly after, the airplane turned north, and the pilot did not respond to the controller's query about the turn.
The Texas Department of Public Safety located the wreckage about 20 miles south of KAMA on open, rolling hill ranch land. The outer wing sections, engines, elevators, vertical and horizontal stabilizers had separated from the fuselage and were found in various directions from the main wreckage.
Personnel Information
The pilot held a commercial pilot certificate with ratings for airplane single-engine land, multiengine land, and instrument-airplane. A third-class Federal Aviation Administration (FAA) medical certificate was issued on October 2, 2012, with the limitation: must have glasses for near vision. On the medical certificate application, the pilot listed total flight time as 1,650 hours, with 50 hours in the preceding six months.
Aircraft Information
The Beechcraft E-90 King Air is a twin-turboprop airplane powered by two Pratt & Whitney PT6A-28 engines, typically configured for five to seven passengers and two pilots. It was maintained under the manufacturer's maintenance program.
Maintenance records showed that the airframe's phase 3 and 4 inspections were completed on March 23, 2012, at a total airframe time of 8,600.2 hours. Phase 1 and 2 inspections were completed on May 23, 2012, at which time the left engine had accumulated 8,456.7 total hours and 1,988.0 hours since overhaul; the right engine had 8,545.7 total hours and 2,781.7 hours since overhaul. The airplane's total time was 8,607.3 hours at that inspection.
The airplane was equipped with a Garmin GDL 69 for XM WX satellite weather, displayed on a Garmin 530 GPS/NAV/COM system, and a Bendix/King KGP 560 enhanced Ground Proximity Warning System (eGPWS).
Meteorological Information
The Area Forecast for the Texas panhandle, issued at 1345 CST, called for scattered clouds or a broken ceiling at 8,000 feet msl with cloud tops to 15,000 feet msl, surface visibility of 3-5 miles in blowing dust, widely scattered thunderstorms with light rain, possibly severe, cumulonimbus tops to FL350, and southerly surface winds of 30 knots gusting to 40 knots. For the eastern half of the Texas panhandle until 2000 CST, the forecast included a broken ceiling at 3,500 feet msl with layered clouds to FL250, scattered light rain showers, and widely scattered thunderstorms with light rain developing between 1400 and 1600 CST, possibly severe, with southerly surface winds of 20 knots gusting to 30 knots.
Two AIRMET advisories were active: one for moderate turbulence below FL180, and another for strong surface winds with sustained magnitudes greater than 30 knots.
Three pilot reports within 50 miles of the accident site, from within three hours of the accident, included moderate turbulence and mountain wave activity.
The Aviation Weather Center issued several convective SIGMETs for Texas valid at the accident time. The Storm Prediction Center also issued Convective Outlook reports concerning the Texas panhandle.
At 1753, the automated weather observation at KAMA reported wind from 210 degrees at 10 knots, with a peak wind at 1714 from 260 degrees at 33 knots, visibility 10 miles, broken clouds at 10,000 feet, temperature 47°F, dew point 38°F, barometric pressure 29.61 inHg.
A regional NEXRAD mosaic for 1805 CST showed a north-south line of high reflectivity (over 50 dBZ) east of the accident site in western Oklahoma, with only light reflectivity near the accident location.
A weather balloon sounding at 1721 CST indicated the troposphere was stable or conditionally unstable, with no temperature inversions below 35,000 feet. Relative humidity exceeded 90% between about 11,000 and 13,000 feet. The freezing level was approximately 8,400 feet. Icing assessments noted potential for moderate clear icing around 12,700 feet and light mixed and rime icing between 10,700 and 13,500 feet, as well as light rime icing between 15,600 and 17,300 feet.
A wind profile showed west-southwesterly winds near the surface at 17 knots, increasing to 51 knots at about 11,000 feet, then backing slightly and increasing to 63 knots through 20,000 feet. Calculations indicated potential for several layers of significant clear-air turbulence below about 13,000 feet.
Communications and Radar Information
The pilot's last contact was with an Albuquerque ARTCC controller, who cleared the airplane to flight level 210 and authorized a course deviation. The pilot did not respond to the controller's query about a turn to the north, and no further communications or distress calls were received.
Radar returns showed the airplane departing and climbing away from KAMA, with a gentle S-type turn heading southerly. The last several radar returns indicated altitudes of 14,700, 14,700, and 14,800 feet before the airplane entered a right turn. The altitude then descended from 14,800 to 14,600 feet during the turn, then dropped to 11,200 feet before altitude data ended.
Wreckage and Impact Information
NTSB investigators, FAA inspectors, and a Beechcraft technical representative examined the wreckage on site. The airplane came to rest in open, rolling ranch land. All major components were accounted for. Pieces including parts of the wings, both engines, and tail section had separated from the fuselage and were located within a 1-mile diameter of the fuselage.
The fuselage sustained heavy impact damage, deformed into an oval shape. The empennage was torn from the rear, the wing spar carry-through section was broken, and the right inboard wing section remained with the fuselage. A 9-foot section of the outboard right wing was found about 115 feet on a 55° heading from the fuselage. The right wing nacelle and engine had separated, with the right engine about 240 feet on a 90° heading. The inboard left wing separated near the wing root and lay adjacent to the primary fuselage ground scar. The outboard left wing was found about 510 feet on a 300° heading, and the left engine about 140 feet on a 40° heading. Both engines showed turbine blade bending consistent with rotation at impact.
Both ailerons had separated from their attachment points and were torn into pieces in the debris field. The vertical stabilizer separated and was found about 610 feet from the main wreckage. The rudder separated into three pieces: the base section about 235 feet beyond the vertical stabilizer, and the top section (without counterweight) another 315 feet beyond that.
Both horizontal stabilizers were found near each other, about 685 feet from the fuselage and 145 feet from the vertical stabilizer. The fuselage's aft bulkhead with elevator torque fittings was nearby.
All examined fracture surfaces showed overstress failures with no evidence of fatigue. Control cable separations were consistent with overload failure. The debris field was consistent with an inflight breakup before impact with terrain.
Medical and Pathological Information
An autopsy was not conducted on the pilot. The FAA Bioaeronautical Sciences Research Laboratory could not perform toxicological tests for carbon monoxide or cyanide. Specimens were negative for ethanol in muscle and liver. Diphenhydramine, an antihistamine commonly marketed as Benadryl, was detected in the liver.
Test and Research
The damaged eGPWS unit was sent to the NTSB's Vehicle Recorder Division for potential download of non-volatile memory. The eGPWS stores data only when certain criteria are met; if an alert or warning activates, it retains data for 20 seconds prior and 10 seconds after.
Data from the eGPWS recorded 22 seconds of information during the descent. During the right turn, the airplane descended from 13,966 feet to 5,904 feet. The descent rate exceeded 18,000 feet per minute, and after 19 seconds, the descent rate exceeded the eGPWS parameter of 32,000 feet per minute.
The remote directional gyro unit was located and had impact damage. The gyro had broken from its mount, and both gyro and gimbal showed marks consistent with rotation at impact. The attitude reference gyro was examined at the NTSB Material Laboratory, also revealing marks consistent with rotation at the time of impact.