Accident Narrative
The pilot reported that no discrepancies were noted during taxi, run-up, and takeoff. After takeoff, the airplane initially climbed with a nose-up attitude of approximately 20 degrees and began a left bank. At about 200 feet above the ground, both the pilot and passenger heard a "bang." Subsequently, the airplane continued to roll to the left, then spun to the right, and impacted a wooded area in a nose-down attitude.
Post-Accident Examination
Examination of the wreckage revealed that a portion of the wooden propeller was almost entirely embedded in a tree branch approximately 3 inches in diameter. The number nine front spark plug was found ejected from the engine. A burned torch mark was present on the underside of the cowling in the vicinity of the number nine cylinder. Additionally, three other spark plugs were found loose in their cylinders.
Maintenance History
Review of maintenance records indicated that an annual inspection had been performed on the airplane about one month prior to the accident. During that inspection, the spark plugs were cleaned, gapped, and rotated. Since the inspection, the airplane had flown approximately 30 minutes.
Relevant Procedures and Publications
The emergency procedures checklist for the same make and model as the accident airplane included setting a descent attitude following an engine failure. Review of FAA publications regarding accelerated maneuver stalls revealed that an airplane will stall at a higher indicated airspeed when excessive maneuvering loads are imposed by steep turns, pullups, or other abrupt changes in flightpath.