History of Flight
On December 17, 2020, about 1637 eastern standard time, a Socata TB10, N5547Y, was destroyed when it was involved in an accident near Pembroke Pines, Florida. The pilot and two passengers were seriously injured, and one passenger was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot stated that the airplane was within the weight and balance envelope, and he performed a preflight inspection using the manufacturer’s checklist with no discrepancies reported. Fuel samples from the three drainage points were free of water and debris. He verified the rear seat occupants were restrained and assisted the right front seat occupant, a minor, with his restraint. The engine started with no issues, and he gave a safety briefing to the passengers. He contacted ground control, received his IFR clearance, and obtained taxi clearance to runway 28L.
While in the run-up area, the pilot completed the engine run-up checklist. Each magneto drop was 75 rpm, within limits. Application of carburetor heat showed a small decrease in engine rpm, which quickly returned when heat was turned off. He advanced the throttle to full and noted 2,700 rpm. He then contacted the control tower and advised he was ready for departure, keeping the engine at 1,200 rpm with mixture slightly leaned. He set flaps and trim to takeoff positions and confirmed all engine gauges in the green. The pilot stated that the fuel selector was not moved from the right tank position throughout the flight.
At 1626:34, the pilot advised local control he was holding short of runway 28L. The controller acknowledged and waited for an IFR release. At 1634:34, the controller cleared the flight for takeoff. No distress call was made by the pilot.
A witness located about 760 ft south-southwest of the approach end of runway 28L reported hearing the engine run-up and then a “definite hard miss” as if running on three cylinders when throttle was applied for takeoff. Another witness reported hearing the engine “popping and banging” from full power application until the airplane was out of sight. The airplane became airborne when abeam the intersection of runway 28L and runway 1R, about 1,542 ft from the threshold. The airplane never climbed above the height of the control tower, climbing to between 50 and 100 ft agl, then descending, then climbing again. The engine problem persisted.
The pilot stated that after takeoff, he moved the mixture to full rich and added full throttle. He obtained 65 knots within normal takeoff distance, rotated, and pitched for 73 knots. At 100 ft agl, the airplane would not climb, airspeed decreased, and the stall warning horn sounded. With significant loss of engine power, he attempted to maintain 70 knots but was unable. He raised the flaps and struggled to keep airspeed above 65 knots while losing altitude. He aimed for a park, initiated a slight left bank, and leveled the wings. At about 20 ft agl, the airplane collided with a tree and then impacted the ground and a fence. Immediately after impact, the airplane became engulfed in flames. The pilot exited by kicking and punching out the side window and assisted the passengers in the right front and left rear seats out of their seatbelts. The adult passenger in the right rear seat had already exited on the right side.
ADS-B data showed the first target just past the departure end of runway 28L, and the flight continued about 0.6 nautical mile west-southwest before the last target near the wreckage.
Aircraft Information
The airplane was a Socata TB10, serial number not specified in the source. Multiple pilots who flew the airplane in the days before the accident reported no issues with the airframe or engine. One pilot reported magneto drops of about 75 rpm, another reported drops within 25 rpm of each other. The airplane was not equipped with an engine monitor or carburetor temperature gauge. A portable ADS-B transceiver and tablet were recovered; the transceiver had no data recording. ForeFlight data recorded about 1 minute 26 seconds of the flight, indicating takeoff from the displaced threshold and the airplane reaching 59 knots groundspeed (64 knots indicated airspeed) about 1,520 ft from the runway 28L threshold.
Maintenance records showed that the left and right front seat restraints were replaced with Anjou Aeronautique 3491423-12-070 16 G restraints at the last annual inspection to comply with Airworthiness Directive 2003-26-06. The rear seat restraints were not changed. According to the Pilot’s Operating Handbook, at design maximum gross weight and the environmental conditions, the takeoff roll and distance to clear a 50-foot obstacle were about 1,135 ft and 1,765 ft, respectively. The airplane was about 12 pounds under design gross weight. The handbook noted distances should be reduced by 10% for each 10 knots of headwind.
The airplane was fueled with 8.51 gallons of 100 low lead fuel on December 14, 2020, after an uneventful flight. The fuel supplier reported no water contamination in their fuel or any fuel-related issues from other aircraft.
Meteorological Information
The reported wind at 1640 from HWO was 340° at 10 knots, temperature 75°F, dew point 70°F, altimeter 30.06 inches of mercury. According to Special Airworthiness Information Bulletin (SAIB) CE-09-35, these conditions (about 80% humidity) were conducive to serious carburetor ice at glide power. The wind provided a 5-knot headwind component for takeoff on runway 28L. The SAIB noted that carburetor ice can be detected by a drop in manifold pressure and roughness in engine operation, and that icing can occur above freezing temperatures due to fuel vaporization and the Venturi effect.
Wreckage and Impact Information
Examination of the accident site revealed the outer section of the left wing with attached aileron in a tree about 8 ft above ground level. The main wreckage, consisting of the fuselage with attached right wing and empennage, came to rest upright near a large tree adjacent to a road, about 3,900 ft west-southwest of the departure end of runway 28L. The cockpit and cabin were nearly consumed by a postcrash fire.
Flight controls for roll, pitch, and yaw showed no evidence of preimpact failure or malfunction. The flaps were in the retracted position. Fuel consistent with 100 low lead was found in the right fuel tank with no water or contaminants; the left fuel tank was ruptured. The right fuel vent system was unobstructed. The left fuel vent line exhibited internal contamination consistent with organic material. The fuel selector was positioned to the left fuel tank, and it sustained heat damage but was internally unobstructed. Metallic shavings were noted in the valve filter bowl. Seat belt buckle assemblies were examined; one buckle from the left rear portion could not be mechanically tested due to fire damage, but X-ray showed no anomalies that would preclude normal unlatching.
The engine separated from the airframe, with the crankshaft fractured aft of the flange. Crankshaft, camshaft, and valve train continuity were confirmed. Compression and suction were observed from all cylinders, and borescope inspection revealed no anomalies. The engine-driven fuel pump was impact fractured and fire damaged; its internal valves appeared normal. The carburetor remained attached; two left side attaching nuts were finger loose, and no liquid drained when inverted. The throttle control was in the full throttle position, mixture midrange. The carburetor fuel inlet screen was unobstructed. Heat damage precluded operational testing; the carburetor bowl showed no obstructions.
The air induction and exhaust systems were unobstructed. Tan to light gray exhaust deposits were observed. The oil system contained an unquantified amount of oil; the oil screen and filter were absent of debris. The single-drive dual magneto was securely attached; it produced spark from all ignition towers during hand rotation, but point gaps were less than the minimum specified. Capacitors passed tests, and the magneto showed no evidence of preimpact failure or malfunction after heating. All spark plugs were gapped within specification and produced bright blue sparks during operational testing.
The propeller governor remained attached, with control cable separated; the governor arm was in the full increase rpm position. One propeller blade was uniform with no bends or gouging; the other blade was bent rearward with no leading-edge gouging or chordwise scratches.