N6182JPiper PA-28-140 · 1976

On December 19, 2008, about 1141 Hawaiian standard time, a Piper PA-28-140, N6182J, collided with trees and a power line during a forced landing following a partial loss of engine power on takeoff initial climb from Kalaeloa Airport, Kapolei, Hawaii. The flight instructor, the private pilot receiving instruction, and the passenger were seriously injured. The airplane was registered to, and operated by, Offshore Flight School, Inc., Honolulu, Hawaii, under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the instructional flight, which originated from Honolulu International Airport about 1020.

The flight instructor stated that "the flight was a complementary pleasure flight for the [flight school] owner’s old friend and his wife." She further stated that the flight was to be a counterclockwise trip around the island of Oahu, with touch-and-go landings at Dillingham Airport and Kalaeloa Airport. The private pilot was in the left front seat, and the instructor was in the right front seat.

The flight instructor said that the flight to Dillingham Airport and the landing there were uneventful. Soon after leaving Dillingham Airport, about 1120, she had the private pilot change the fuel selector from the left tank to the right tank. About 1135, when the airplane was about 4 miles west of Kahe power plant, she contacted Kalaeloa Airport tower for landing instructions and was given clearance for the option to runway 4L. The airplane was level at 1,500 feet mean sea level when she had the private pilot reduce power and glide towards the runway. The flight instructor said they did not use carburetor heat nor did they clear the engine during the glide. She was not sure what setting the throttle was at during the descent, only that they were gliding towards the runway.

The private 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. The flight instructor 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. She called the tower and started a left turn back towards the runway and away from terrain ahead that was "full of bushes." The flight instructor estimated that the airplane reached a maximum height of about 200 feet above ground level. She did not recall the impact sequence, but believed the airplane hit a power line.

The flight instructor, age 40, held a commercial pilot certificate with airplane single engine land and instrument airplane ratings. Additionally, she held a flight instructor certificate with a rating for single engine land airplanes issued on November 4, 2008. The instructor’s most recent second-class Federal Aviation Administration (FAA) medical certificate was issued on April 23, 2008, with the limitation, must wear corrective lenses. She reported that she had about 465 hours of flight experience of which 70 hours were in the same make and model as the accident airplane, and that she had given about 17 hours of flight instruction.

The private pilot, age 59, held a private pilot certificate with an airplane single engine land rating. He did not have a current FAA medical certificate; his most recent third-class medical certificate was issued on January 5, 1998.

The airplane was a single engine, propeller driven, four-seat airplane, with dual flight controls, which was manufactured by Piper Aircraft, Inc., in 1976. It was powered by a Lycoming O-320-E3D reciprocating, direct drive, air cooled, normally aspirated engine, which had a maximum takeoff rating of 150 horsepower at sea level.

The most recent annual inspection was completed on April 19, 2008, at a tachometer reading of 3,702.24 hours; a 100-hour inspection was completed on November 9, 2008, at a tachometer reading of 3,802.24 hours. At the time of the 100-hour inspection, the engine had accumulated 1,823.6 hours since major overhaul. The airplane’s tachometer read 3,823.24 hours at the time of the accident. Examination of the aircraft maintenance records revealed no evidence of any uncorrected maintenance discrepancies.

According to the Pilot’s Operating Manual (POM) for the airplane, during approach and landing, "carburetor heat should not be applied unless there is an indication of carburetor icing, since the use of carburetor heat causes a reduction in power which may be critical in case of a go-around." The Emergency Procedures section of the POM, under the heading Engine Roughness, states, in part: "Engine roughness is usually due to carburetor icing which is indicated by a drop in rpm, and may be accompanied by slight loss of airspeed or altitude. If too much ice is allowed to accumulate, restoration of full power may not be possible; therefore prompt action is required. Turn carburetor heat on."

At 1153, the weather conditions at Kalaeloa Airport (elevation 30 feet), Kapolei, were as follows: wind 130 degrees at 8 knots; visibility 10 statute miles; cloud cover scattered at 2,200 feet; temperature 77 degrees Fahrenheit; dew point 70 degrees Fahrenheit; altimeter setting 30.05 inches of Mercury. Plotting these conditions on a carburetor icing probability chart indicated that they were in the range for serious icing at glide power. The calculated relative humidity was 79 percent.

FAA inspectors who responded to the accident site reported that the airplane impacted trees and a power line before sliding across a road and coming to rest. The impact heading was about 135 degrees magnetic. There was no evidence of fire.

The fuselage with the right wing folded back came to rest on its left side on the west side of the road. The right wing displayed impact damage along the full span of the leading edge with heavier damage to the tip area and to the fuel tank, which was ruptured and crushed aft to the spar. The empennage remained intact with no apparent damage to the vertical stabilizer and rudder. The horizontal stabilator was in place and secure, but had impact damage to both sides.

The left wing separated from the fuselage and was found on the east side of the road; there was impact damage to the leading edge outboard of the fuel tank and near the tip area. The left wing fuel tank remained intact and contained about 16 gallons of blue colored fuel.

When examined by the FAA inspectors, the fuel tank selector valve was found near the right tank position. The carburetor heat control was found in the off position. The throttle control was found in the closed position, and the mixture control was found about halfway between the full rich and idle cutoff positions. A first responder told FAA inspectors that he had moved a red handle, which was likely the mixture control, aft.

On January 21, 2009, under the supervision of the NTSB investigator-in-charge, the wreckage was examined by a representative of the airframe manufacturer. Control continuity was verified for all flight controls, except for impact and recovery related separations to the aileron control cables. Examination of the fuel tank selector valve, which had been removed from the fuselage prior to this date, revealed that the fuel valve inner fitting was slightly out of the detent for the right fuel tank position and offered about 80 percent of the normal opening for fuel to pass.

The propeller had remained secure to the engine and was removed after recovery. Both blades were bent aft. One blade displayed 'S' bending. Both blades showed leading edge damage as well as chordwise scratches consistent with rotation at the time of impact.

The engine crankshaft was rotated by hand and compression, suction, and valve train continuity were verified to all cylinders and to the accessory gears. Examination of the cylinders with a lighted borescope revealed no anomalies. The magnetos were removed and rotated by hand and produced spark on all towers.

The engine driven fuel pump was manipulated by hand and found to operate normally. The carburetor was separated by impact, and part of the top was broken away near the throttle valve. The carburetor was disassembled and no anomalies were noted. The filters for both the electric fuel pump and the gascolator were free of blockage. The finger strainers in the fuel tanks and all associated fuel lines were free of blockage. No engine anomalies were noted during the examination.

An article on induction icing provided by the engine manufacturer, available at www.Lycoming.com/support/tips-advice/key-reprints/pdfs/key%20 Operations.pdf, states that 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 article further states that it is "appropriate to use full carburetor heat, if needed, to prevent icing when operating at low power for instrument approaches, or for flight in the traffic pattern."

The FAA publication, Pilot’s Handbook of Aeronautical Knowledge, recommends the following procedure for use if carburetor icing conditions are suspected and closed-throttle operation is anticipated:

"Adjust the carburetor heat to the full ON position before closing the throttle and leave it on during the closed-throttle operation. The heat will aid in vaporizing the fuel and help prevent the formation of carburetor ice. Periodically, open the throttle smoothly for a few seconds to keep the engine warm; otherwise the carburetor heater may not provide enough heat to prevent icing."