Aviation Accident Summaries

Aviation Accident Summary ERA14LA346

Elliott Key, FL, USA

Aircraft #1

N737TP

CESSNA 172N

Analysis

The student pilot departed on a local, solo instructional flight. According to the flight instructor, the student was briefed to complete three takeoffs and landings and to stay in the airport traffic pattern. Instead, the student completed one takeoff and landing and then departed the airport traffic pattern. Witnesses reported seeing the airplane in level flight about 2 hours later over the ocean 20 miles from the departure airport. Two witnesses said that the airplane's nose "pitched up" momentarily before the airplane descended vertically at "full power." One witness described the sound of the engine as "wide open" and noted that it was accelerating throughout the descent. All of the witnesses said that the airplane went "straight down" and that it did not rotate. Examination of the wreckage revealed damage consistent with a vertical descent at high speed and no preimpact mechanical anomalies. The autopsy report determined that the cause of death was "airplane crash." For the airplane to descend straight down, the forward pressure on the yoke must be increased proportionally with the increase in airspeed. If control positions remained constant, the dive would shallow out as it progressed.

Factual Information

HISTORY OF FLIGHTOn July 20, 2014, at 1446 eastern daylight time, a Cessna 172N, N737TP, operated by Dean International Inc., was destroyed when it collided with the Atlantic Ocean following a vertical descent near Elliott Key, Florida. The student pilot was fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed for the flight which departed Kendall-Tamiami Executive Airport (TMB), Miami, Florida, about 1244. The solo instructional flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 141. According to the pilot's flight instructor, the purpose of the flight was for the student pilot to remain in the traffic pattern at TMB and complete 3 takeoffs and landings. The airplane was dispatched at 1140, and the school was notified of the accident by a 911 operator at 1446. According to information from the Federal Aviation Administration (FAA), the airplane took off about 1230 and remained in the traffic pattern for 15 minutes before it departed the airport traffic area. Four witnesses on the west side of Elliott Key provided statements to the police and their summaries of the events were consistent throughout. Two witnesses said their attention was drawn to the sound of the airplane's engine. They said the engine was "wide open" and at "full power" as the airplane descended vertically out of view on the west side of the key, and the sound of impact was heard. Two witnesses said the nose of the airplane "pitched up" momentarily before the airplane descended vertically at full power. In a telephone interview, one of the four witnesses said, "The airplane went straight down, steady. Like it was flying straight down. It was like he either had a heart attack, or did it deliberately. The airplane did not spiral or spin, the wings were parallel with the water the whole way down." According to another witness, the engine was "wide open. He never let off the throttle; it was running at full power." A third witness said the airplane went straight down, with no spiral or spin, and that the sound of the engine got "faster and faster, and louder and louder." He said, "The airplane appeared intact, but was going straight down. I expected him to pull up, but he never pulled up." PERSONNEL INFORMATIONThe pilot held a student pilot certificate with an endorsement to perform solo flight in the Cessna 172. His most recent FAA first-class medical certificate was issued on February 11, 2013. An examination of the pilot's logbook revealed that he had logged 145 total hours of flight experience, of which 105 hours were in the Cessna 172. Examination of the logbook further revealed that the pilot had logged 40 hours during the 1980's and had resumed flight training in 2013. AIRCRAFT INFORMATIONAccording to FAA and maintenance records, the airplane was manufactured in 1977. Its most recent annual inspection was completed June 4, 2014, at 18,366 aircraft hours. The airplane accrued approximately 30 hours of flight time after the inspection. According to the airplane manufacturer, the Cessna 172 had "conventional" stall characteristics, and an aural warning sounded between 5 and 10 knots above the stall. Typically, one wing will stall before the other, and the airplane will then enter a spin around the stalled wing. If the flight control positions remain unchanged, the airplane would continue in the spin, and achieve a steady-state descent. The stall and spin may be arrested by the proper flight control inputs by the pilot, or, if the flight controls were relaxed by the pilot, the spin would likely progress to a nose-down, spiraling descent. METEOROLOGICAL INFORMATIONAt 1458, the weather reported at Homestead Air Reserve Base (HST), 10 miles west of Elliott Key, included few clouds at 2,000 and the wind was from 090 degrees at 8 knots. The temperature was 33 degrees C, the dew point was 24 degrees C, and the altimeter setting was 30.05 inches of mercury. AIRPORT INFORMATIONAccording to FAA and maintenance records, the airplane was manufactured in 1977. Its most recent annual inspection was completed June 4, 2014, at 18,366 aircraft hours. The airplane accrued approximately 30 hours of flight time after the inspection. According to the airplane manufacturer, the Cessna 172 had "conventional" stall characteristics, and an aural warning sounded between 5 and 10 knots above the stall. Typically, one wing will stall before the other, and the airplane will then enter a spin around the stalled wing. If the flight control positions remain unchanged, the airplane would continue in the spin, and achieve a steady-state descent. The stall and spin may be arrested by the proper flight control inputs by the pilot, or, if the flight controls were relaxed by the pilot, the spin would likely progress to a nose-down, spiraling descent. WRECKAGE AND IMPACT INFORMATIONThe wreckage was recovered to and examined at Ft. Pierce, Florida, on July 25, 2014, and all major components were accounted for at examination. The engine compartment, instrument panel, cockpit, cabin area, wings and empennage were completely destroyed by impact and fragmented into very small pieces. The largest sections were the vertical fin, horizontal stabilizer, elevator and landing-gear support structure with landing gear attached. The engine was still attached to the instrument panel area by wires and cables. Control cable continuity was established from the cockpit area to the rudder and elevator. Cable continuity was traced to the ailerons through several cable and bellcrank breaks, all of which displayed failures consistent with overload. The engine was separated from the main wreckage and displayed significant impact damage. The propeller was attached, and both blades displayed similar twisting, curling, and aft bending. The starter displayed rotational scoring on its face. All engine accessories were separated by impact except the right magneto. The crankshaft was rotated by hand at the propeller flange and continuity was established through the powertrain and valvetrain to the accessory section. Thumb compression was confirmed on all cylinders using the thumb method. Neither magneto would produce spark when tested due to salt water immersion and corrosion. Disassembly revealed no visual evidence of mechanical anomaly. MEDICAL AND PATHOLOGICAL INFORMATIONThe Miami-Dade County Medical Examiner Department, Miami, Florida, performed the autopsy on the pilot. The autopsy report listed the cause of death as "airplane crash." The FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed forensic toxicology on specimens from the pilot. Ethanol was detected in the muscle and blood, but none was detected in the liver. The sample sites and quantities detected were consistent with post mortem production of ethanol.

Probable Cause and Findings

The airplane’s vertical descent into water for reasons that could not be determined because postaccident airplane examinations revealed no mechanical anomalies.

 

Source: NTSB Aviation Accident Database

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