NTSB Factual Report

HISTORY OF FLIGHT

On October 16, 2005, about 1325 eastern daylight time, a Cessna 172P, N99173, registered to Christiansen Aviation, Inc., operated by Ari Ben Aviator, experienced an in-flight loss of control during initial climb shortly after takeoff from La Belle Municipal Airport, La Belle, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 instructional flight from St. Lucie County International Airport (FPR), Fort Pierce, Florida, to La Belle Municipal Airport. The airplane was substantially damaged and the student pilot, the sole occupant, was fatally injured. The flight originated about 1227 from FPR.

On the day of the accident, about 0800, the student pilot met with her flight instructor, who reviewed her pre-flight planning and endorsed her logbook for a solo cross-country flight from Fort Pierce to Airglades Airport in Clewiston, Florida, and return. The student pilot completed this flight, and again met with her instructor, who reviewed her pre-flight planning and endorsed her logbook for another solo cross-country flight from FPR to La Belle and return. During this meeting, the student pilot expressed concern about the communication radio in the airplane, N4954G, a Cessna 172N, she had just flown. The flight instructor stated that he had heard her transmissions clearly, but offered to switch airplanes with the student pilot, which they did. The student pilot then departed on her second cross country flight of the day in the accident airplane.

A witness who was outside at the La Belle airport reported seeing the airplane in the traffic pattern and believed he saw the pilot perform more than one landing on runway 32. He noted the airplane flew past his position one time and then returned. During the second time on the upwind leg for runway 32, while flying at an estimated altitude of 150 feet, the airplane stalled, drifted to the left, and impacted the ground. He drove to the scene and while en route called 911. After arriving on-scene, he noted fuel leaking from under the instrument panel, and he turned off the master switch. In an attempt to rescue the pilot, he cut the seatbelt and shoulder harness. He also reported that the engine was running until impact. It sounded "normal," and he did not hear any sputtering.

Another witness, who was flying near the La Belle airport in a helicopter equipped with a Traffic Alert and Collision Avoidance System (TCAS), reported seeing the accident airplane on the upwind leg of runway 32; the TCAS display depicted the airplane as flying at his altitude (approximately 350 feet). He looked and saw the airplane, which appeared normal. He diverted his attention momentarily to look for other traffic, then looked back and saw the airplane in a nose-low attitude. The airplane completed 3 to 3.5 turns of a spin before he lost sight of it. He did not hear a distress call, nor did he hear an emergency locator transmitter.

PERSONNEL INFORMATION

The student pilot, a citizen of the United Kingdom, held a second class medical and student pilot certificate issued on August 2, 2005, with the limitation, must wear corrective lenses. She started a 14 CFR Part 141 private pilot through airline transport pilot course at Ari Ben Aviator on September 2, 2005. According to her pilot logbook, she had accumulated approximately 44 hours total time of which 6 hours were solo flight time. All of the student pilot's flight time was in Cessna 172s. The logbook and student pilot certificate were endorsed for solo flight and cross country flight dated September 27, 2005, and October 13, 2005, respectively.

AIRCRAFT INFORMATION

Examination of the airplane's maintenance records revealed that the 1985 model Cessna Skyhawk received its most recent annual inspection on August 26, 2005, at a total airframe time of 9,546.6 hours. The most recent 100-hour inspection was completed on September 26, 2005, at a total airframe time of 9,646.7 hours. At the time of this 100-hour inspection, the engine, a Lycoming O-320-D2J, S/N L-9100-39A, had accumulated 1,882.2 hours since major overhaul. When the accident occurred, the airplane had been flown about 66.3 hours since this 100-hour inspection.

The student pilot's flight instructor reported that on October 11, 2005, he had encountered a discrepancy with the airplane where the flaps would not retract from a 20 degree down position. The flight instructor stated that he "moved the flap lever to retract the flaps, and the flaps and the flaps position indicator did not move." He further stated that he "reset the flap lever to the original position and tired again. This time the flaps and flaps position indicator moved normally." The flight instructor did not report the discrepancy to maintenance personnel. According to the flight logs for the airplane, it was flown 10 times between this flight and the accident flight. Written statements were obtained from the pilots for 8 of these flights and none reported any duplications of this discrepancy. The pilot for the remaining 2 flights had left the United States and could not be contacted.

According to the 1985 Skyhawk Information Manual, the wing flaps are extended or retracted by positioning the wing flap switch lever (selector) on the instrument panel to the desired flap deflection position. Maximum flap deflection is 30 degrees. The switch lever is moved up or down in a slotted panel that provides mechanical stops at the 10 degree and 20 degree positions. A scale and pointer (indicator) on the left side of the switch lever indicates flap travel in degrees. Normal takeoffs are accomplished with wing flaps 0 to 10 degrees. Normal landings can be made with any flap setting from 0 to 30 degrees.

METEOROLOGICAL INFORMATION

At 1253, the reported weather conditions at Fort Myers, Florida, located approximately 22 nautical miles southwest of the accident site, were wind variable at 6 knots, visibility 10 statute miles, sky clear, temperature 30 degrees C, dew point 14 degrees C, and altimeter 29.91 inches.

WRECKAGE AND IMPACT INFORMATION

The accident site was on airport property, approximately 370 feet south of the departure end of runway 32. The airplane came to rest nose down with the empennage nearly vertical in an 8 to 10 inch deep impact crater. The engine and firewall were displaced aft, and the instrument panel was fragmented. The nose landing gear was bent aft. The fuselage lower and side skins displayed compression folding up the aft door posts. Both wing leading edges were crushed aft from the wing roots to the tips. Both fuel tanks were breached. Browning vegetation from fuel exposure was observed on both sides of the impact crater. The fuel strainer was free of debris.

All flight control surfaces remained attached to their respective attach points. Control continuity was verified for the ailerons, rudder, elevator, and elevator trim. The flap jackscrew was extended 4.9 inches, which according to the Cessna representative, equates to a full flap or 30 degree position. The impact damaged flap selector handle was near the 10 degree position. The flap selector and indicator assembly was removed from the wreckage and retained for further examination. The terminals were separated from the rear of the assembly. Flap electrical circuit continuity was verified from the separated terminals to the flap motor.

The engine remained partially attached to the airframe, and the propeller remained attached to the engine crankshaft flange. The propeller was buried in the ground, and the propeller spinner was crushed. Both propeller blades exhibited aft torsional bending, and one blade displayed leading edge abrasion. The engine crankshaft was fractured aft of the propeller flange, around about 90 percent of its circumference. The fractured surfaces of the crankshaft exhibited signatures indicative of impact overload. The impact-damaged portion of the crankshaft was removed to facilitate further examination of the engine. The crankshaft was rotated by hand using a drive tool inserted into the accessory section and continuity of the crankshaft, camshaft, valve train, and accessory drives was established. All four cylinders produced thumb compression when the engine was rotated. Borescope examination of the cylinders revealed no anomalies. Both magnetos produced spark from all towers when rotated by hand. The oil suction screen and oil filter element were found clean.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy was performed by the Office of the District Medical Examiner, Fort Myers, Florida. Toxicological testing by the FAA's Toxicology and Accident Research Laboratory detected no carbon monoxide, cyanide, ethanol or drugs.

TESTS AND RESEARCH

The flap selector/indicator assembly was examined at the NTSB Materials Laboratory in Washington, DC. Impact marks from the flap selector handle were observed on the right hand side of the slot in which the selector rotates. The marks indicate that the flap selector was positioned at approximately 10 degrees at the time the impact marks were made. Impact marks from the flap position indicator wire were observed on the bracket that houses the flap selector and indicator mechanisms. The marks correspond to the indicator wire being near the bottom of its slot (near 30 degrees) at the time of impact.

ADDITIONAL INFORMATION

The airplane, with the exception of the retained flap selector/indicator assembly, was released to a representative of the owner on October 18, 2005. The flap selector/indicator assembly was returned to the owner's representative on June 28, 2007.

NTSB Probable Cause

The student pilot's failure to maintain airspeed during the initial takeoff climb, resulting in an inadvertent stall/spin and uncontrolled descent to ground impact. A contributing factor was the failure of the wing flap control, which resulted in the flaps being stuck in the full down position.