Piper PA-28-140 N6182J accident near Kapolei, Hawaii

Probable cause

The partial loss of engine power during the initial climb due to the failure of both pilots to use carburetor heat during a long descent for landing in carburetor icing conditions, and, the flight instructor's inadequate supervision of the flight.

NTSB analysis

The airplane was level at 1,500 feet mean sea level when the flight instructor had the private pilot receiving instruction reduce power and glide towards the runway for a touch-and-go. The flight instructor stated that they did not use carburetor heat nor did they clear the engine during the glide. The pilot landed the airplane and while still rolling, advanced the throttle for takeoff. Immediately after liftoff, the flight instructor noted that the engine was not accelerating above 2,100 rpm. She took control of the airplane, checked the engine instruments, fuel tank selector position, and fuel pressure, and confirmed that the throttle and mixture controls were full forward. The flight instructor did not apply carburetor heat. The flight instructor estimated that the airplane reached a maximum height of about 200 feet above ground level before impacting trees and a power line. Examination of the airframe and engine revealed no evidence of any preimpact mechanical discrepancies that would have prevented normal operation. Although the fuel tank selector valve was found slightly out of the detent for the right tank position, it still offered about 80 percent of the normal opening for fuel to pass. According to the engine manufacturer, carburetor ice can form "under moist conditions (a relative humidity of 50 percent to 60 percent is moist enough) with any outside air temperature from 20 to 90 degrees Fahrenheit." The calculated relative humidity at the time of the accident was 79 percent. Plotting the recorded temperature of 77 degrees Fahrenheit and the dew point of 70 degrees Fahrenheit on a carburetor icing probability chart indicated that the conditions were in the range for serious icing at glide power. The partial loss of engine power was likely a result of the formation of carburetor ice.

Text from the NTSB. Open the NTSB docket for WPR09FA060 for the full record.