Aviation Accident Summaries

Aviation Accident Summary MIA00FA260

ODESSA, FL, USA

Aircraft #1

N3WT

Beech B-95

Analysis

The accident aircraft was found in a field after an emergency locator transmitter beacon had made an alert of a possible accident having occurred. At about 1225, a witness, who had also been a student pilot, was in a housing development near where the accident aircraft was found, and he said that he had observed an aircraft maneuvering at a low altitude, just above the tree line. He said he saw the aircraft enter a steep bank, and start a dive with its left wing down. According to the witness, the aircraft then went below the tree line, and he waited for signs of an impact, such as noise or smoke, but did not hear or see anything. He said he then assumed that the pilot might have recovered enough to set the aircraft down in the field. He said the aircraft had descended as an eagle would, had it been attacking a small animal. FAA Tampa Approach radar information showed that the accident aircraft had been at 300 feet at 1221:44, and it had climbed to a maximum altitude of 1,100 feet at 1223:35. At 1224:21, radar information showed the aircraft at 700 feet, prior to all radar information being lost. The accident occurred during daylight hours, in visual meteorological condition, and examination of the accident aircraft did not reveal any preexisting failure or malfunction to the aircraft or any of its systems. The accident aircraft propeller signatures that were found were consistent with the left propeller having been feathered, and the right propeller rotating upon impact.

Factual Information

HISTORY OF FLIGHT On September 4, 2000, about 1225 eastern daylight time, a Beech B-95, N3WT, registered to, and operated by a private individual, as a Title 14 CFR Part 91 personal flight, crashed near Tampa Bay Executive Airport, Odessa, Florida. Visual meteorological conditions prevailed, and no flight plan was filed. The aircraft incurred substantial damage, and the commercial-rated pilot, the sole occupant, was fatally injured. The flight originated from Tampa Bay Executive Airport, the same day, about 1200. A student pilot stated that about 1225, he and his wife were house shopping in a new housing development, close to the wooded area where the accident aircraft was found, when he saw a low slow flying airplane coming from the "north/northeast." The student pilot further stated that the aircraft was just above the tree line when it began to descend, while in a 45-degree banking turn to the left. He said he assumed that the pilot flying the aircraft was practicing turns or training, since he was close to the airport. The student said he told his wife that this guy must be crazy, and just as he said that, he saw the aircraft enter a steep bank, and start a dive with the left wing down. He said that the aircraft then went below the tree line. He said that he and his wife waited for signs of an impact such as noise or smoke, but they did not hear or see anything, so they assumed an that the pilot might have recovered enough to set it down in the field. The student said that the aircraft had maneuvered as an eagle would, when attacking a small animal. According to an official with the FAA Flight Service Station (FSS) in St. Petersburg, Florida, FSS personnel received an alert from the U.S Air Force Rescue Coordination Center, informing them that an emergency locator transmitter had been operating in the area of the Tampa Bay Executive Airport. A search was then initiated, and at 1705, the accident airplane was discovered in a sparsely wooded area, about 2 miles northwest of the airport. Recorded radar data from the FAA Tampa Approach Control showed that the flight was observed on radar at 1221:44, at an altitude of 300 feet msl, and a ground speed of 61 knots. At 1223:35, the flight was observed at 1,100 feet msl, and a ground speed of 85 knots. At 1224:21, radar information showed that the flight was located about 345 degrees, and 14.37 nautical miles from the Tampa International Airport approach control radar, at 700 feet msl, and the aircraft had a ground speed of 107 knots. This was the last radar contact with the FAA Tampa Approach Control. PERSONNEL INFORMATION FAA records indicate that the pilot, age 55, held an FAA commercial pilot certificate, with airplane single and multiengine land instrument airplane ratings, issued on February 9, 1993, and a flight instructor certificate, with airplane single land and instrument ratings, last issued on May 4, 2000. The pilot also held an FAA third class medical certificate, with the limitation that the pilot must wear corrective lenses for distant vision, issued on November 2, 1998. According to the pilot's logbook, at the time of the accident the pilot had accumulated over 1,876 hours total flight experience, with about 631 hours in multiengine aircraft. The logbook information also showed that the last entry in the pilot's logbook, was for a flight which occurred on July 18, 2000, and according to a flight instructor, that was the date he had been given a biennial flight review. AIRCRAFT INFORMATION N3WT is a Beech B95 Travel Air, serial number TD-409, which was manufactured in 1960. At the time of the accident the aircraft had accumulated about 4,841 flight hours. The aircraft received an annual inspection on April 5, 2000, about 39 flight hours before the accident. The airplane was equipped with two wing mounted Textron Lycoming O-360-A1A, 180 horsepower engines, and at the time of the accident, they had accumulated about 282.6 hours. The left and right propellers were both two bladed constant speed Hartzell propellers, and both had received major overhauls on November 25, 1995. METEOROLOGICAL INFORMATION Visual meteorological conditions prevailed at the time of the accident. The St. Petersburg-Clearwater International Airport 1253 surface weather observation was sky clear, visibility 10 statute miles, wind from 210 degrees at 7 knots, temperature 89 degrees F, dew point temperature 71 degrees F, altimeter setting 29.87 inHg. WRECKAGE AND IMPACT INFORMATION N3WT crashed in a relatively open sandy area, consisting of grass, shrubs, and sparse trees, on Starke Ranch, in Pasco County, Florida. The trees in the area of the wreckage were about 50 to 75 feet high, with the closest ones being a short distance behind the main wreckage, but there was no evidence of the trees having been impacted, which was consistent with the aircraft impacting at a steep angle. The aircraft was located in position 28 degrees, 13.265 minutes north latitude, 082 degrees, 37.389 minutes west longitude, and it had come to rest on a magnetic heading of about 075 degrees. All components of the aircraft, which were necessary to sustain flight, were located in the immediate vicinity of the main wreckage of the aircraft, and there was no evidence of a fire and/or an explosion at the scene. The aircraft's nose/baggage area had been crushed, and was pushed rearward to about 12 inches forward of the windshield, and the nose had also been twisted slightly to the right as a result of the impact. The fuselage had broken just aft of the rear spar carry through structure, resulting the aft fuselage being bent upward at about a 55- to 60-degree angle. The impact marks/crush line, when measured in relation to the horizontal plane, showed that the angle of impact had been about 55 degrees, in a nose down attitude, and both wing engine pylons had dug into the ground at a depth sufficient to permit the forward fuselage and wings to lie flat on the ground. Both wings exhibited chordwise crushing, with crushing on the right wing being more extensive than that of the left. The chordwise crushing had extending from the wing tip to the engine mount, consistent with the right wing having struck the ground first. Continuity of the flight controls was confirmed for roll, pitch, and yaw by tracing the cables to the respective flight control surfaces. There was no evidence of damage to the flight control surfaces on the empennage, and there also was no evidence that the flight controls had incurred any preimpact failure or malfunction. The right aileron had been detached and was in close proximity to the main wreckage, and the left aileron as well as both flaps had remained attached to the respective wings. Both flap actuators had separated at the clevis, and the left flap actuator's measurement was 1.75 inches, which equated to a flap setting of zero degrees. The right flap actuator's measurement was 1.50 inches, which also equated to the flaps being retracted. The aileron actuator trim setting was 1.5 inches, which equated to about 1 degree of downward deflection. The rudder trim actuator's measurement was 1.60, which was consistent with about 3 degrees of left rudder trim. Examination of the landing gear actuator revealed that the landing gear had been "up", at the time of the accident. Fuel was present in all four tanks, and all four fuel tank bladders had been breached. There was also a strong smell of fuel in the sand, in which had seeped to a depth of about 8 inches. Both mixture controls were full forward, and both propeller controls as well as both throttles controls were also full forward. Primers were also "in and locked." The engine tachometer was found with the needle for the left engine off the scale on the high side of the gage, and the needle for the right engine at 1,150 rpms. Fuel selector knobs were in the "Main" position for both main tanks. Seats and seat rails were intact, but there had been impact damage to both, with the left seat having suffered the most damage. According to rescue personnel who responded to the accident, the pilot's lap seat belt had been fastened when they first arrived at the scene, and had been moved only to facilitate rescue. The aircraft was not equipped with shoulder harnesses. The left engine had remained attached to the airframe, but it had sustained impact damage at its forward and bottom areas. When the crankshaft was rotated, continuity was established throughout the rotating group, valve train and accessory section. Compression was obtained on cylinders 1, 3 and 2. The No. 4 cylinder had incurred damage at the exhaust pushrod assembly, and was being pinched, preventing closure of the exhaust valve, but when the constriction was relieved, compression on No. 4 cylinder was obtained. The top spark plugs on the left engine were removed and examined, and combustion signatures were consistent with normal operation, and valves were intact and were undamaged. The left magneto had sustained impact damage, but the drives functioned when rotated, and a spark was produced at all terminals of both magnetos. The carburetor had been detached during the impact sequence, but when examined, exhibited signatures consistent with overload. The carburetor float bowl contained about 2 ounces of fuel, and there were no visible signs of fuel contamination or obstruction to the carburetor, fuel, or induction systems. The carburetor float arm and pontoons had remained intact, but the pontoons displayed evidence of hydrodynamic deformation. The right engine had also remained attached to the airframe, but it had incurred damage to the right forward, and bottom areas of the engine. The No 4. cylinder exhaust pushrod assembly, as well as the engine oil sump, were damaged and there was crushed metal, measuring about 55 degrees with respect to the horizontal. Mechanical continuity was established throughout the rotating group, valve train and accessory section, and compression was observed on all four cylinders. The cylinder combustion chambers were examined, and had been undamaged, and the valves were also intact with no evidence of valve to piston contact. Signatures associated with the spark plugs, combustion chambers, and the exhaust system components appearances were consistent with normal operation. The left magneto had incurred impact damage, and had detached from the mounting pad, but when tested, the drive to both magnetos were functional, and sparks were produced at each terminal. The carburetor had been detached from the engine, and the signatures associated with the separation were consistent with an overload condition. The carburetor and induction systems were free of obstructions, and about 1/2 ounce of fuel was found in the carburetor supply line. The carburetor bowl was full of engine oil as a result of the oil sump and float bowl being compromised, and the carburetor float arm and pontoons had remained intact, with the right pontoon showed evidence of hydrodynamic deformation. The two-bladed constant speed propeller on the left engine, along with the spinner had remained attached at the crankshaft flange, and the blades had remained attached to the hub. The piston and pitch change mechanism had sustained impact damage, and the signatures found, revealed that the propeller was at an angle consistent with it having been in feather at the time of the accident. Continuity of the propeller governor oil circuit was established, and the left propeller governor had remained securely attached at the mounting pad. The governor's control rod had detached from the control arm, and it exhibited signatures consistent with overload. The two-bladed constant speed propeller on the right engine had detached from the crankshaft, just aft of the flange, and it, along with its spinner, were found beneath the right engine, in the small crater. Examination of the separation surface revealed signatures consistent with a torsional overload. Both propeller blades had remained attached, with one blade being bent aft in a smooth arc, and having leading edge burnishing and chordwise striations across the cambered surface, as well as a slight torsional twist and trailing edge "S" bending. The other propeller blade was bent aft in a smooth arc, and it also had displayed leading edge burnishing and chordwise striations across the cambered surface MEDICAL AND PATHOLOGICAL INFORMATION Marie H. Hansen, M.D., Associate Medical Examiner, District Six, Largo, Florida, performed the postmortem examination on the pilot, and according to Dr. Hansen, the cause of death was attributed to traumatic crush injuries. The Medical Examiner's Office conducted toxicology studies on specimens from the pilot for carbon monoxide, ethanol and drugs, and the tests were positive for caffeine in the urine. The FAA Toxicology Laboratory, Oklahoma City, Oklahoma, conducted toxicology studies on specimens from the pilot for ethanol and drugs and none were present. ADDITIONAL INFORMATION On September 9, 2000, the NTSB released the wreckage of N3WT to Mr. J. J. Franko, Chief of Maintenance, Central Florida Jets Inc.

Probable Cause and Findings

the pilot's failure to maintain Vmc, which resulted in a loss of control, and collision with the ground. Contributing to the accident was the pilot's decision to feather a propeller powered by an operational engine, while at a low altitude.

 

Source: NTSB Aviation Accident Database

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