The private pilot reported that the engine cylinders had been replaced and the flight was to continue a cylinder break-in period. The engine run-up and propeller check were completed during the taxi to the runway to keep the ground run-up to a minimum.
After engine start, no anomalies were noted.
Break-in procedures called for lower cylinder head temperatures and less than full power at the beginning of takeoff, according to the pilot. After the Cessna 170B took off and reached about 100′ above ground level (agl), he slowly reduced rpm and the manifold pressure to about 65% power.
At 200′ agl, the engine lost partial power. The engine briefly regained some power, but it then lost power again.
The pilot executed a forced landing in mesquite tree-covered terrain near Ingleside, Texas.
A post-accident examination and functional test of the engine revealed no anomalies that would have precluded normal operation. The pilot stated that he believed the engine lost power due to carburetor ice, and the weather conditions at the time of the accident were conducive to serious carburetor icing at cruise power. It is likely that the engine lost power due to carburetor icing.
Probable cause: The loss of engine power during takeoff due to carburetor icing, which resulted in a forced landing.
NTSB Identification: CEN16LA078
This January 2016 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.