N734SY

On August 29, 2024, about 1717 eastern daylight time, a Cessna 172N, N734SY, was substantially damaged when it was involved in an accident near Lynchburg, Virginia. The pilot received minor injuries. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 test flight.

According to the pilot, the preflight inspection was normal, oil and fuel was at capacity, and the flight controls were free and correct. The preflight engine run was normal with the oil pressure indicating 60psi, oil temperature was in the green arc, the magneto checks at 1,700 rpm showed normal rpm drops, and the carburetor heat check showed a normal rpm drop.

He then taxied to runway 10 at Falwell Airport (W24), Lynchburg, Virginia for takeoff. All systems were normal. He added power for takeoff, the airspeed came alive, and the tachometer read about 2,200 rpm. He then established an indicated airspeed of 80 knots during the initial climb. All systems were normal and indicated in the green arc. The oil pressure reading was above the middle of the green arc. Upon reaching approximately 1,300 feet above mean sea level, the engine incurred a complete power loss and seized, with the propeller stopping within 3 seconds. He then turned left (back in the direction of the airport), as he had seen a couple of open areas over his left shoulder.

At this time, he was communicating on the common traffic advisory frequency, and he made “Mayday” distress calls that were heard by employees at W24, and he picked an open area behind a hotel. His flight path was over the back yards of houses. As he approached the open area the left wing impacted a tree which yawed the airplane 90 degrees. The airplane then impacted the ground, bounced, hit the ground again, and then slid to a stop. The pilot then egressed through the right passenger door.

Postaccident examination of the airplane revealed that it was substantially damaged. The fuselage was intact with buckling and wrinkling on the right side, both aft of, and below the passenger door. The front windscreen was broken in several places. The empennage was mostly undamaged. The rudder and elevator were undamaged. Control cable continuity from the rudder and elevator were established to the cockpit.

The right wing displayed impact damage to the outboard portion of the aileron, but the aileron moved freely. Skin buckling from impact forces was visible on the wing on the outboard forward, bottom surface.

The left wing was wrinkled and bent in several locations. Crush damage to the leading edge was apparent over most of the wing. The left aileron was substantially damage from the impact. The left flap was damaged.

The nose landing gear had sheered during the impact. The remaining strut structure was pushed upwards and aft towards the engine firewall. The left and right main landing gear were sheared off.

The cockpit was mostly undamaged. The primer was in and locked. The master switch was in the “off” position. The ignition was in the “off” position. There were no tripped circuit breakers observed. The parking brake was in the off position. The pitot head, landing light, and navigation light switches were in the “off” position. The beacon light and strobe light were in the “on” position. The carburetor heat lever was in the off position. The throttle and mixture control levers were observed in an idle and idle-cutoff position, respectively. The flap lever was in the full down position. The fuel selector was in the “off” position.

Examination of the propeller revealed that, one blade was straight and undamaged. The second blade was bent slightly aft from the impact with terrain. No rotational signatures were observed on the propeller.

The fuel system fed from the high wing fuel tanks, through the fuel selector, to the airframe fuel strainer, then directly to the engine carburetor. Compressed air was blown through the fuel selector in the off, right, left, and both positions and no discrepancies were noted. The fuel strainer contained a fine, sandy material in the bottom of the bowl that had a red tint in color. Fuel remained in the fuel strainer. The remaining fuel was tested with a water finding paste and no water was present. The inlet to the carburetor was clean. The carburetor was secured to the bottom of the engine sump housing and was undamaged. The carburetor was opened for further investigation. Minor debris was found in the bottom of the carburetor bowl. The main jet was clear. The plastic floats were undamaged.

All spark plugs remained installed in their respective cylinder heads and were undamaged. The top spark plugs were a combination of massive and fine wire electrodes. The bottom spark plugs were all fine wire electrodes. All spark plugs displayed coloration consistent with normal engine operation. The top spark plugs were bench tested and all four produced a bright blue spark.

The cylinder intake pipes were secured and undamaged from the sump housing to their respective cylinder heads. The number 3-cylinder intake tube was removed, and no blockages or debris was found within the engine sump housing. The engine air bracket filter was crush damaged but appeared clean. The air hose from the bracket filter housing to the carburetor was crushed from impact forces.

The heater muff was crush damaged from impact forces. The muffler was inspected with a borescope and no blockages were observed. Minor organic matter was observed at the tailpipe from the impact events. There were no exhaust leak signatures noted.

The ignition harness was undamaged, and the leads were run to their appropriate cylinder locations from the dual magneto.

Continuity from the front of the engine to the rear accessory gears was confirmed, and thumb compression and suction was present on all four cylinders. Examination with a lighted borescope did not reveal any anomalies and the intake and exhaust valves were undamaged.

The oil filter had a large quantity of what appeared to be engine assembly oil. Minor amounts of ferrous/non-ferrous metal were found in the filter. The suction screen was not present within the oil sump. The oil pump was removed, and no evidence of rotational scoring was observed within the pump. The oil passages were checked for blockages with safety wire, but no blockages or obstructions were observed. The oil pressure relief valve ball was clean. No nicks or indents on the ball or seat observed. The oil cooler by-pass valve displayed a uniform seating witness mark. The oil sump contained approximately 5 quarts of clean engine oil.

The wreckage was retained by the NTSB for further examination.