NTSB Factual Report

HISTORY OF THE FLIGHT

On July 4, 2000, about 0750 central daylight time, a Cessna 152, N89043, registered to and operated by SDS Inc., as a Title 14 CFR Part 91 instructional flight, crashed during takeoff/initial climb from Murfreesboro Municipal Airport, Murfreesboro, Tennessee. Visual meteorological conditions prevailed, and no flight plan was filed. The commercial-rated flight instructor was fatally injured, and the student received serious injuries. The aircraft incurred substantial damage. The flight was originating at the time of the accident.

The airplane crashed on the front lawn of the residence located at 1718 Dover Street, Murfreesboro, Tennessee. The aircraft had departed from the Murfreesboro Municipal Airport where it had taken off on runway 18. The student pilot in the accident airplane stated that it had been a normal day, and they had performed the preflight, and then proceeded to takeoff. He said that the only unusual event was that during the engine "runup", as they performed the magneto check, one magneto indicated a lower than acceptable reading, and they diagnosed the cause as due to the spark plug being fowled. He said they performed a procedure where they held the brakes and increased the power for about 30 to 45 seconds. He said they then performed another magneto check, and the rpm "drops" were in the correct range. According to the student, he performed the takeoff, and the aircraft got about 50 to 100 feet in the air, and appeared as if it did not have enough power to fly. He said that the aircraft engine was not operating rough, nor had it ever sputtered or displayed any problems, but the airplane just was not climbing, and seemed as if it did not have enough power to fly. He said that his instructor immediately took over the duties of the pilot flying, and turned the aircraft back toward the airport or possibly to the nearby ball field. The student said throughout the whole flight the engine "rpms" were correct, and the engine noises were normal. The student said that as they were executing the turn back to the airport, the last thing he remembered was the stall warning horn going off after the turn was initiated, and just before they dropped.

The student stated that it had been his fourth flight lesson, and the three prior lessons had been in a Cessna 172. He said that there had been a scheduling conflict with the aircraft he normally flew, and that the flight school had a total of three airplanes, two Cessna 172s and one Cessna 152, and the one he usually flew was the 160-horsepower Cessna 172. He said there was a 180-horsepower Cessna 172 available, but he did not want to pay the extra $20.00 to rent it for the lesson. He stated that he and his instructor did not discuss weight and balance, or aircraft performance in preparation to the lesson, and at the time of the flight the aircraft had been topped off with fuel. He also said that at the time of the accident he weighed 194 pounds, and he believed that his instructor weighed about 175 to 185 pounds. According to the student the only additional weight that they had in the cabin was his logbook, and the instructor's small backpack, which contained his logbook and headphones.

A witness on the ground stated that the airplane took off to the south, and the engine sounded as if it was laboring during the climb. The witness further stated that it appeared as if the airplane was not gaining altitude. According to the witness, the airplane leveled off, and entered a hard right hand turn and the engine sputtered, almost as if it started and stopped, but the witness said he could not be sure if it actually stopped. According to the witness, as the airplane was in the bank it leveled out slightly, ad somehow missed the trees, and headed in the direction of the ball field. The witness said he was certain the engine was operating when it crashed.

A student pilot, taxiing an airplane about midfield on the airport, said that he noticed the accident airplane lift off at about the 3/4 length of the runway. According to the student, it was slow, at an altitude of about 100 feet, and was not climbing any higher. The student further stated that he saw the nose pitch up, and then lower. The student said that the airplane then entered a shallow turn to the right, and heard a voice on the Unicom frequency say that he had an emergency and was turning back to land on runway 36. The student said he lost sight of the airplane as it went behind trees.

PERSONNEL INFORMATION

Records obtained from the operator confirmed that the flight, during which the accident occurred, had been the student pilot's fourth flight lesson. The student's logbook indicated that he had accumulated a total of 3.3 flight hours, commencing with his first flight on June 19, 2000. At the time of the accident, the student did not yet possess a student pilot certificate, and was being given primary flight instruction by the flight instructor.

Records obtained from the Federal Aviation Administration (FAA) showed that the flight instructor held a commercial pilot certificate with airplane single and multiengine land instrument ratings, issued on May 4, 1999. The flight instructor also held a flight instructor certificate with an airplane single engine land rating, last issued on March 7, 2000, as well as a second-class medical certificate, last issued on April 30, 1998. The flight instructor had accumulated about 482 total flight hours, with about 100 of flight instruction given. Within the last 90 days the flight instructor had flown about 79 hours, and within the last 30 days he had flown about 33 hours.

AIRCRAFT INFORMATION

N89043 is a 1978 model Cessna 152, serial number 15282607, registered to SDS INC., Murfreesboro, Tennessee, and it had received an annual inspection on February 15, 2000. On April 3, 2000, the aircraft received its last 100-hour inspection prior to the accident. The aircraft had accumulated a total of 3,603.3 hours on the airframe.

The aircraft was equipped with a 110-horsepower, Lycoming O-235-L2C engine, serial number L-14656-15. The engine had accumulated 85.7 hours since inspection, and a total of 1604.9 hours since overhaul. The aircraft was equipped with a McCauley propeller, whose model number was TCM6958, and whose serial number was FH014.

WEIGHT AND BALANCE

At the time of the accident the airplane was estimated to weigh about 1,713 pounds, and the center of gravity was estimated to be at 33.12 inches aft of datum. It is estimated that the airplane contained 24.5 gallons of fuel at the time of the accident.

According to the Aircraft information handbook, the maximum allowable weight for the airplane is 1,670 lbs. The forward center of gravity limit is 31.0 inches aft of datum at 1,350 pounds or less, with straight-line variation to 32.65 inches aft of datum at 1,670 pounds. The aft center of gravity limit is 36.5 inches aft of datum at all weights.

METEOROLOGICAL INFORMATION

Visual meteorological conditions prevailed at the time. The Murfreesboro Municipal Airport 0800 surface weather observation was sky clear, visibility 10 statute miles, wind from 220 degrees at 3 knots, temperature 81 degrees F, dew point temperature 71 degrees F, altimeter setting 30.11 inHg.

WRECKAGE AND IMPACT INFORMATION Examination of the accident scene revealed that the aircraft had scraped the right front portion of the roof of the house next door at 1714 Dover Street, and had broken small branches off a tree, which grew at the edge of the house, prior to impacting the lawn at 1718 Dover Street. The aircraft came to rest on a heading of 140 degrees magnetic. There were propeller slash marks, 14 inches apart, on the grass, along with a small impact crater, and the angle of incidence along the descent path was about 45 degrees nose-down attitude. Prior to the aircraft coming to rest, it had spun around, and was facing in a direction nearly opposite to that of its final descent path, as indicated by the scars on the roof and the ground, as well as the accompanying debris field. A postcrash fire had ensued, and extensive fire damage had occurred to the right wing, cabin, and engine accessory portion of the aircraft. The area where the aircraft wreckage lay, displayed a small circle of burnt and brown grass as a result of the fire, and the effects of spilled aviation fuel. The aircraft wreckage had come to rest a few feet from the house, but there had been no damage to the structure.

Examination of the aircraft revealed that the propeller had been torn loose from the engine crankshaft, with the six steel flange bushings having been pulled out, and the crankshaft flange bent. The debris field was largely localized, and the propeller had been detached, but it had and had come to rest a short distance from the main wreckage. The carburetor bowl and the right magneto had also both torn loose during the impact, and they lay a short distance away from the main wreckage. One of the propeller blades exhibited torsional bending, and chordwise abrasions, as well as leading and trailing edge damage, consistent with that of a rotating propeller on impact, while the other blade had remained straight.

The right wing contained about half a tank of fuel, and the fuel exhibited characteristics consistent with that of 100-octane low lead aviation fuel, and all fuel samples were clear of water and/or debris. The fuel tank fitting had failed when the trailing edge of the wing separated from the fuselage, and had allowed fuel to drain and feed the postcrash fire. The left wing tank had only trace amounts of fuel, and both fuel tanks had ruptured, exhibiting characteristic hydraulic bulging signatures associated with the impact. The fuel vent lines in the left wing, as well as the vented fuel cap in the right wing were clear of obstructions. The fuel selector handle was intact and secured to the valve, with the handle positioned midway between "off" and "on" placards, and it and exhibited contact signatures as a result of the cabin floor having buckled against the fuel selector handle.

Flight control continuity was established for all flight controls through their respective bellcranks and pulleys for all three axis. The flaps had appeared to be set to at least half of the available flap range, and when the flap actuator was examined, it verified that they were indeed extended, with the measurement equating to a 20-degrees flap extension. The flap motor was connected to battery power and tested, with the flaps functioning normally, and the horn type stall warning system also functioned normally when suction was applied.

The engine had remained partially attached at the firewall, and it displayed impact damage to the lower and rear sections, in addition to heat damage associated with the postcrash fire. There was some deformation to the tubular mounts and the control cables. Fuel system lines were either damaged, and/or had been destroyed. The carburetor had fractured into several fragments, and the metal float, as well as the one-piece venturi, had both also fragmented, and some portions were not recovered. The main fuel nozzle had broken off, and also was not recovered. The right magneto had broken from the accessory pad, but upon examination, the gear timing was normal. Both magnetos fired from all towers when they were field-tested. The ignition harness was destroyed, and the level of destruction precluded any possible test.

The engine core had remained intact, and its examination showed that there had been considerable fire damage. When the engine was rotated, continuity of the crankshaft, camshaft, valve train, valve action and accessory drives was verified. All four cylinders were removed and inspected, and no evidence was found to indicate any mechanical failure or malfunction. All spark plugs had a light tan color, displayed carbon deposits, which were consistent with the appearance of the spark plugs and the combustion chambers, with the exception of the No. 2-bottom spark plug, which was oil soaked. The spark plug electrodes possessed light to moderate wear, and their gap settings were normal. When examined, the No. 4 top plug had been installed with two gaskets.

Examination of the engine oil suction screen and oil filter showed that the oil was uncontaminated, and examination of the induction air box showed that it was clear of any obstructions, but the air induction filter element had been burned.

MEDICAL AND PATHOLOGICAL INFORMATION

The student pilot and the flight instructor both sustained serious injuries and were admitted to the hospital, but the flight instructor later succumbed to his injuries.

Toxicological testing was performed on specimens from the student pilot during admission to the hospital for drugs, and alcohol, and all test results were negative.

Dr. Bruce P. Levy, Resident Pathologist, Office of the Chief Medical Examiner, Nashville, Tennessee, performed the postmortem examination on the flight instructor. The cause of death was attributed to thermal burns and smoke inhalation. A contributory cause of death was also determined to be blunt force injuries of the torso and extremities. No findings, which could be considered causal to the accident, were reported.

Aegis Analytical Laboratories, Nashville, Tennessee, as well as the FAA Toxicology Laboratory, Oklahoma City, Oklahoma performed toxicological studies on specimens obtained from the flight instructor. The tests were negative for carbon monoxide, cyanide and ethanol. The tests were positive for Diazepam and Nordiazepam, which were detected in the blood. Nordiazepam was also detected in the liver.

TESTS AND RESEARCH

Examination of the crash site revealed two propeller slash marks that were 14 inches apart. Based on the slash marks, the estimated ground speed at impact for the two bladed propeller, with a 1.1 engine/propeller gear ratio was 41 knots, and the estimated engine speed was about 1,774 rpms.

The density altitude at the time of the accident was estimated to be about 2,000 feet.

ADDITIONAL INFORMATION

On July 6, 2000, the NTSB released the wreckage of N89043 to Mr. Eric Niehoff, General Manager, SDS Inc., Murfreesboro, Tennessee.

NTSB Probable Cause

the flight instructor's failure to maintain an airspeed above the aircraft's stall speed, which resulted in a stall/mush, and an inflight loss of control while maneuvering to return to a landing area during an emergency, resulting in an uncontrolled descent and collision with a residence, and the ground. Factors contributing to the accident were an improper flap setting, and the aircraft's gross weight being exceeded.