At about 1015 eastern time, a Rockwell 112A burned after a forced landing near Hanscom Field. The two pilots received minor injuries. The pilots reported being in cruise flight when they noticed smoke in the cockpit. The shut down the electrical system, and then the engine began to vibrate. They shut down the engine so it wouldnt vibrate off the frame and then noted a fire had started in the engine compartment. The pilots opted to land on a flat area on the Concord River floodplain, but the airplane hit the tops of trees about 100 yards prior to reaching the floodplain, and a tree bent over and deposited the airplane on the ground upright. The airplane was consumed by fire.