CEN16FA095

The pilot's failure to maintain adequate airspeed while turning from the base leg to final, which resulted in the wing's critical angle-of-attack being exceeded and a subsequent aerodynamic stall.

The airline transport pilot was repositioning the airplane to its home base after maintenance was completed at a repair station. The pilot filed an instrument flight rules (IFR) flight plan with a cruise altitude of 9,000 ft mean sea level (msl). The en route portion of the flight to the destination was uneventful. Before descending to approach altitude, the pilot contacted approach control and reported that he had received weather information for the destination airport. The pilot then requested and was given clearance to fly the area navigation (RNAV) approach to runway 7. Approach control cleared the pilot to descend to 3,000 ft msl and issued pilot reports for icing. The pilot flew the RNAV approach to runway 7, tracking inbound to the airport on the published approach course. About 5.8 miles from the airport, the pilot cancelled his IFR clearance and continued inbound under visual flight rules. His recorded altitude at the time of IFR cancellation was 2,700 ft msl. Reported weather at the airport at the time of the accident included a ceiling of 1,700 ft above ground level (2,649 ft msl) and wind from 240 degrees at 9 kts, gusting to 14 kts, and variable from 240 to 330 degrees. One witness at the airport saw the airplane enter a downwind leg to land into the wind on runway 25. As the airplane began its turn from the base leg to final, several other witnesses saw it nose down and descend to impact in wooded terrain about 300 ft short of the runway threshold. A postaccident weather study showed high icing potential within the cloud layers above the surface and a likelihood of moderate or greater icing along the airplane's route of flight until the airplane descended below the cloud ceiling. Because the surface temperature was below freezing, any structural ice that built up on the airplane while it descended through the clouds would not have melted after the airplane descended below the cloud ceiling. An examination of the airplane revealed no preimpact mechanical malfunctions or anomalies that would have precluded normal operations. Data recovered from the airplane's Remote Data Module showed that the airplane's anti-ice tank switch was turned on about 7 minutes 30 seconds before the accident and remained on for 1 minute 50 seconds. The switch was then turned off and remained off for the remainder of the flight. The airplane's flaps were extended to the "HALF" position about 2 minutes 50 seconds before the accident. Just before the data ended, the airplane's pitch and bank increased, and the stall warning activated. In the last 3 seconds of data, the airplane's bank angle was 48 to 50 degrees, and the indicated airspeed was between 87 and 90 kts. The Pilot's Operating Handbook for the airplane showed that at 60 degrees of bank with half flaps, the airplane's stall speed was 95 kts. It is possible that, during the approach, ice accumulated on the airplane, which may have increased the airplane's stall speed. However, regardless of whether or not structural ice was present, during the turn to final, the pilot allowed the airspeed to decrease below the airplane's published stall speed. As a result, the wing's critical angle-of-attack was exceeded, and the airplane entered an aerodynamic stall and departed controlled flight.

The results of an autopsy performed on the pilot on January 27, 2016, by the Montgomery County, Ohio, Coroner, Dayton, Ohio, showed the cause of death to be from acute ventricular dysrhythmia and multiple blunt force trauma sustained in an airplane crash. The FAA's Civil Aerospace Medical Institute performed forensic toxicology on specimens from the pilot. The results were negative for all tests conducted. At 1732, the routine aviation weather report for I19 was wind 300 at 6 kts, ceiling 1,800 ft overcast, 10 statute miles visibility, temperature 0 degrees Celsius (C), dew point -02 degrees C, and altimeter 30.13 inches Hg. At 1658, the routine aviation weather report for Wright Paterson Air Force Base (FFO), Dayton, Ohio, 343-degrees at 9 nm from I19, was wind 240 degrees at 9 kts, ceiling 200 ft overcast, visibility 10 statute miles, temperature 01 degree Celsius (C), dew point -03 degrees C, altimeter 30.10 inches Hg, and remarks variable ceiling height 170 ft. to 220 ft. At 1753, the routine aviation weather report for FFO was wind 250 at 11 kts, gusting to 17 kts, ceiling 190 ft overcast, visibility 10 statute miles, temperature 0 degrees Celsius (C), dew point -04 degrees C, altimeter 30.12 inches Hg, and remarks sea level pressure 207 hPa. The upper air balloon sounding from Wilmington, Ohio, 165 degrees at 18 miles from I19, taken at 1900 showed high icing potential within the cloud layers above the surface. The upper air balloon was released into air that was drier above 5,000 ft mean seal level (msl). However, the infrared satellite imagery from 1730 to 1815 showed cloud top temperatures of -12 C, which corresponded to cloud tops around 12,000 ft indicating the likelihood of moderate or greater icing along the airplane's route of flight until 1752 when the airplane descended below the cloud ceiling. However, with the surface temperature at freezing and no warm layer above that, any ice built up on the airplane would not have melted before reaching the ground. The weather radar imagery showed no precipitation falling from aloft to the surface so cloud droplets remained in the air and in the clouds The area forecast issued at 1345 and valid for the accident time called for broken ceilings at 3,000 ft msl with cloud tops as 12,000 ft msl and visibilities of 3 to 5 miles in freezing mist. There were Airmen's Meteorological Information (AIRMETs) issued at 1545 for instrument conditions, ceiling below 1,000 ft and/or visibilities below 3 miles in precipitation and/or mist, and for moderate icing conditions below 12,000 ft. The Center Weather Service Unit in Indianapolis Center issued a meteorological impact statement warning of occasional moderate rime and mixed icing between 2,000 and 5,000 ft msl. Pilot reports received two hours prior to the accident and 1 hour after the accident showed for the area around I19, light and moderate rime to moderate mixed icing in the clouds below flight level 200. A query of Lockheed Martin Flight Service and DUATS indicated the pilot did not contact either for weather or Notices to Airmen (NOTAMs). The pilot, age 33, held an airline transport pilot certificate with an airplane single-engine and multi-engine land, instrument airplane rating, and rotorcraft helicopter and instrument helicopter rating. Additionally, the pilot held a flight instructor certificate with ratings in single and multi-engine land, instrument airplanes and helicopters. According to the pilot's logbook, the pilot had recorded 2,075 total flying hours and 100 flying hours in the 90 days preceding the accident. Additionally, he recorded having 200 hours in the accident airplane and 80 hours in the accident airplane within the preceding 90 days. The pilot had successfully completed an instrument proficiency check flight on October 1, 2015. The pilot held a valid first-class medical certificate dated May 9, 2015. The certificate showed no restrictions or limitations. The airplane wreckage was found in a lightly wooded ravine about 300 ft short of the runway 25 threshold, approximately on bearing with the runway. The airplane impacted in a nose down vertical attitude. Trees and brush immediately adjacent to the wreckage showed little damage. The airplane was oriented on a 284-degree magnetic heading and was located at 39.693888 degrees North longitude, and -83.983611 West latitude, at an elevation of 932 ft msl. The entire airplane was confirmed to be in the in the vicinity of the initial ground impact. The ground underneath the airplane's engine was pushed outward and up, consistent with it being the initial point of impact. The engine was twisted to the left and resting on its left side. The propeller hub was separated from the crankshaft aft of the propeller mounting flange and lay uphill from the airplane. The crankshaft at the fracture showed a torsional, shear separation consistent with the crankshaft turning at high speed at the time of the fracture. Two of the composite propeller blades were found on the ground between the airplane and the propeller hub. Both of the blades showed leading edge gouges and dents. The blade that remained with the propeller hub showed minimal damage. The airplane's cowling was broken out and found resting forward of the airplane wreckage. The nose landing gear strut was fractured in multiple locations and was located on the ground immediately adjacent to the bottom of the engine. The airplane was equipped with the Cirrus Airframe Parachute System (CAPS), a Ballistic Recovery System (BRS). Evidence at the accident site showed that the CAPS system was not activated in flight. The charge cartridge for the parachute deployment mechanism was found expended, due to impact forces. The fuselage remained predominantly intact. The cabin floor structure and bottom of the fuselage showed upward crushing from the firewall aft to the fuselage station 306 bulkhead. The wing and spar cover were separated. The cabin roof was intact, however first responders had cut the A and B-pillars and laid the cabin roof to the side of the airplane to facilitate the recovery of the pilot. It remained attached to the fuselage by the CAPS activation cable and other wires. The left cabin door broken out from the fuselage and was crushed and fractured. The right cabin door remained attached to the detached cabin roof section by its upper hinge and showed crush damage. The baggage door was separated from the fuselage and showed crush damage. The firewall was crushed aft displacing the rudder pedal wells and twisted the cockpit center console. The windscreen and all of the cabin windows were broken out. Pieces of Plexiglas were located around the airplane in all directions. The instrument panel was broken downward and aft. However, most of the components, instruments and switched remained intact. The BAT 1&2, ALT 1&2, avionics, and pitot heat switches were found in the ON position. All other bolster switches were in the OFF position. The panel dimmer knob was at the 7 o'clock position, the windshield dimmer knob was broken off. The flap switch was in the UP position. The fuel selector was set to the right tank. The oxygen switch was in the OFF position and all of the oxygen cannulas were stored in their storage bag, which was found on the ground near the airplane. The fan selector was set to zero and the hot/cold selector knob was set to full hot. The standby altimeter was set to 30.09 and displayed an altitude of 1,040 ft. All four seats showed upward crushing due to impact. The pilot seat was positioned forward of the seat stop. The energy absorption module in the pilot seat was crushed approximately 2-3 inches in the center while the four corners remained higher. Both airbag seatbelts had deployed. The pilot airbag vent holes were both squared and the airbag showed a 2-inch cut. A ground scar was present immediately forward of the right wing that spanned the entire length of the righ