Looking for some technical help on my 912ULS. I lost power shortly after takeoff and crashed in a school yard. My plane is a Slepcev Storch. I just purchased it and put the wings on and was doing my first test flights. It has 215 hours total time. My first flight went well and I did a full power climb to 4,500 (2,300 AGL) at 1,000 FPM with no issues except for slightly warm oil temp (120 deg. C). I came back down and landed and removed the engine cowling. This helps expose the oil cooler to a more direct airflow. That was about a 15 minute flight. The second flight without the cowling was a climb back up to 4,500 MSL and now the oil temp was at 100 C. The OAT was around 87 deg F. This flight lasted about 45 minutes and everything seemed fine and the engine never missed a beat. My climb RPM was 5,400. I landed and came to a full stop. I then took off with about 1,000 feet of runway remaining. The Storch gets off at 35 kts and about a 150 feet.
Now this is where it all goes bad. Shortly after liftoff I must have lost some power as the plane wasn't climbing as it should have been. At around 65 feet AGL the engine really started to lose power and surged very slightly and the plane started to lose altitude. At 50 feet I made a quick decision to turn 140 degrees to the left and crash into a small school yard as there was nothing but buildings straight ahead. The engine must have quit completely as the prop was not turning upon impact.
I pancaked the plane into the grass area so that I wouldn't fly/crash into the house 200 feet away. I am luckly that I was not injured as my landing gear took as the impact and colasped completely.
My post crash inspection has not revealed anything so far that would explain this engine failure. I suspect a fuel issue. Checks performed so far. Fuel tanks had 4 gals remaining in each side and I was running on both tanks. Both carbs overhauled 2 hours ago and new fuel pump installed. No water in any sumps, gascolator full of fuel and clean, all fuel hoses are without any obstructions, both carb bowls were full of fuel and clean, carb slides move easily and vacuum diaphragms as new,all jets clear, float weights in spec, all carb cables working normally, all ignition wiring intact, fuel pump removed and inspected internally and appears OK (new pump). Checked the resistance of all ignition stator coils per MM. Charging coils both 4.0 ohm (3.2-4.5 acceptable), all 4 trigger coils 240 ohms (220-250 acceptable). All ground wires were removed and cleaned prior to the flight. The ignition P-leads were rewired using correct toggle switches and new ground wires.
The plane flew 20 hours prior with no changes to the fuel system. The fuel plumbing on this is odd as the fuel return line coming from the manifold just goes back to the fuel supply hose going to the engine pump. This hose is about 10 inches long. It does not have a restrictor oriface, it's just a 1/4 inch hose back into a T. It does not return to the fuel tank. This is how the AFM shows the fuel system. How can the pump provide any pressure to the carbs like this?
Any ideas would be greatly appreaciated. I will be redesigning the fuel system and putting in an electric aux fuel pump and a pressure regulator (for the carbs) returning to a header tank.
Before and after pics
