Accident Details
On May 27, 2011, at approximately 1430 central daylight time, a Grumman G-164A single-engine airplane, registration N2LU, was substantially damaged when it impacted trees near Oak Ridge, Louisiana. The airplane was registered to and operated by Barham Brothers, Inc. The certified flight instructor (CFI) and the pilot both sustained minor injuries. Visual meteorological conditions prevailed, and no flight plan had been filed for the 14 Code of Federal Regulations Part 137 agricultural training flight. The local flight had departed from Hooks Memorial Airport (M79) in Rayville, Louisiana, about 1330.
Pilot and CFI Statements
The CFI reported that he was flying the airplane at a low altitude and demonstrating a pass to the pilot. He had been flying at about 80 to 90 mph during the low passes with the engine power set at 22 to 23 inches of manifold pressure. The CFI made a flat teardrop turn to reenter the field when he noticed a loss of engine power and a slight loss of altitude. The CFI then leveled the wings to stop turning and maintain altitude, but the descent continued, and the airplane impacted the tops of several trees. Forward movement briefly stopped, and the airplane then fell nose first through the thick wooded canopy, coming to rest in the trees in a mostly nose-down attitude.
The pilot reported that the CFI had been flying the airplane down to 60 mph while in wingover turns and that the stall light would regularly flicker on and off during the climbing turns. The pilot also reported that the CFI did not increase the engine power setting before impact and that the airspeed was 60 mph or less immediately before the airplane impacted the trees.
Examination and Testing
The impact resulted in substantial damage to all four wings, the ailerons, the fuselage, and the empennage. The CFI did not report using carburetor heat during his low-altitude operations but did report operating at a reduced power setting. According to a carburetor icing probability chart, an airplane operating in the ambient conditions at the time of the accident could expect a risk of carburetor icing at cruise power and a serious risk at glide power. Before recovering the wreckage, the operator reported that they were able to successfully test run the engine. An examination of the airplane showed no preimpact mechanical malfunctions or failures that would have precluded normal operations.
Aircraft Performance Data
The G-164A Pilot's Handbook indicates a power-off stall speed of about 67 mph and a best rate of climb speed of 83 mph when operating at 4,500 pounds on a standard day. The handbook also shows that a 50 percent power setting at that weight would require about 27.7 inches of manifold pressure, yielding a cruise speed of 99 mph.