Aviation Accident Summaries

Aviation Accident Summary FTW04FA079

Valley Spring, TX, USA

Aircraft #1

N6175Y

Cessna 210N

Analysis

Prior to departure, the 580-hour, non-instrument rated private pilot obtained two weather briefings from an automated flight service station (FSS). A briefer reported that an AIRMET for IFR conditions was in affect and VFR was not recommended across the proposed route of flight. The AIRMET for IFR conditions would continue beyond 0900 and end at 1200. In addition, a briefer told the pilot to contact FSS while en route and obtain weather advisories. The pilot departed about 0915, and there are no records that he contacted FSS while airborne. Examination of the last one minute of data revealed the target was at an altitude of 5,400 feet msl, on a heading of 102 degrees at 158 knots, when it made a right 180-degree turn, before the data ended at 1039. A witness said the weather conditions at the time were light drizzle, haze, limited visibility, and that it had been raining, but had "just let up." He heard the airplane circle overhead for several minutes followed by a loud explosion at 1045. According to FAA Flight Training Handbook Advisory Circular (AC) 61-21A, "If neither horizon or surface references exist, the airplane's attitude must be determined by artificial means - an attitude indicator or other flight instruments. Sight, supported by other senses such as the inner ear and muscle sense, is used to maintain spatial orientation. However, during periods of low visibility, the supporting senses sometimes conflict with what is seen. When this happens, a pilot is particularly vulnerable to spatial disorientation." A toxicology report detected hydrocodone, a narcotic analgesic, in the pilot's liver and kidney. Since blood was not available for testing, it is not possible to determine when the pilot may have ingested the prescribed medication or whether he may have been impaired from it. Hydrocodone may cause some people to become drowsy, dizzy, or lightheaded. According to an FAA flight surgeon, using hydrocodone within 24 hours of flying is not recommended.

Factual Information

HISTORY OF FLIGHT On February 22, 2004, approximately 1045 central standard time, a Cessna 210N single-engine airplane, N6175Y, registered to and operated by a private individual, was destroyed upon impact with terrain while maneuvering near Valley Spring, Texas. The non-instrument rated private pilot, sole occupant of the airplane, was fatally injured. The airplane was registered to Baley Aviation, LLC, of Richmond, Texas. Instrument meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight that originated at Midland International Airport (MAF), near Midland, Texas, approximately 0915, and was destined for Sugarland Regional Airport (SGR), near Sugarland, Texas. A review of voice communications revealed that the pilot had obtained two weather briefings from the San Angelo Flight Service Station (AFSS), San Angelo, Texas, prior to departure. The pilot reported that he would operate under visual flight rules (VFR) and his route of flight would be from Midland to San Angelo to Burnet to Sugarland, Texas, at an altitude of 5,500 feet mean seal level (msl). He planned to depart about 1000. The first weather briefing was obtained at 0651, at which time, the briefer reported that an AIRMET for instrument flight rules (IFR) was in affect and VFR flight was not recommended across the proposed route of flight. The briefer informed the pilot that the AIRMET for IFR conditions would continue beyond 0900 and end at 1200. The pilot told the briefer that he would call back prior to his departure for another weather briefing. The second weather briefing was obtained at 0851. The pilot asked for an update to the AIRMET, and wanted to know if it was still in effect. The briefer responded that an update for the AIRMET was not available and to call back in 15 minutes. The pilot then requested weather information for airports along the route of flight. At the end of the briefing, the briefer advised the pilot to contact Flight Service in-flight on 122.6 for updated weather information. A review of air traffic control (ATC) communications revealed that the pilot did not request weather advisories during the flight. A review of radar data revealed a target emitting a VFR transponder beacon code traveling southeast bound from Midland toward Valley Spring, Texas. Examination of the last one minute of data revealed the target was at an altitude of 5,400 feet msl, on a heading of 102 degrees at 158 knots, when it made a right 180-degree turn, before the data ended at 1039. The last radar return was approximately 30 degrees, 52 minutes north latitude, and 098 degrees, 46 minutes west longitude, and at an altitude of 5,300 feet msl. A witness was standing outside his home located about one mile north of the accident site when he heard a small airplane approaching from the south-southeast. He said the airplane was traveling in a west to northwest direction, and seemed to be having engine trouble because it was "speeding up then throttling back." The witness listened to the airplane for approximately one minute, and recalled that the engine noise seemed to get worse because it began to "spit and sputter." Suddenly, the engine "revved" really high then shut off for a split second, followed by a loud explosion, "thud" and smoke. The witness said the weather conditions at the time were light drizzle, haze, limited visibility, and that it had been raining, but had "just let up." He stated that the airplane sounded like it was circling, because it stayed in the area for a few minutes. The witness called 9-1-1 at 1045. A certified flight instructor provided a statement to the Investigator-In-Charge (IIC) regarding the weather he encountered on an instructional flight from Midland to Burnet (BMQ), near Burnet, Texas. The flight was on an instrument flight rules flight plan and was cleared to an altitude of 7,000 feet msl. At that altitude, they were above a scattered-to-broken layer of clouds, until approximately 30 nautical miles west of the Llano, Texas, VOR. He said, "At that point, we entered the clouds and did not break out again until on the approach at BMQ." They landed at BMQ at 1230, following a fairly lengthy hold at the initial approach fix waiting for traffic inbound to Horseshoe Bay to clear. During this period the weather was deteriorating rapidly. At the time they entered the clouds, the ceiling at Burnet was 2,600 feet msl. The flight instructor said, "Just after passing the Llano VOR, reported ceiling was 1,600 feet msl and by the time we initiated the approach it was called variable between 500 feet msl and 900 feet msl with visibility down to one mile in rain and mist. We broke out right at the MDA for the approach which is 650 feet msl. Shortly after landing, rain intensity increased and the ceiling and visibility were further reduced." PERSONNEL INFORMATION The pilot held a private pilot certificate with a rating for airplane single-engine land. His most recent Federal Aviation Administration (FAA) third-class medical certificate was issued on September 24, 2002, with a limitation to wear corrective lenses while flying. Examination of the pilot's logbooks revealed he had accumulated a total of 580.1 flight hours, of which 1.3 hours were in actual instrument conditions and were conducted under the supervision of a certified flight instructor (CFI). METEOROLOGICAL INFORMATION Weather conditions at Midland International Airport, at 0853, were reported as wind from 120 degrees at 5 knots, visibility 10 statute miles, overcast skies at 1,100 feet, temperature 8 degrees Celsius, dew point 4 degrees Celsius, and an altimeter setting of 29.99 inches of Mercury. Weather conditions at Burnet Municipal Airport, 22 nautical miles west of the accident site, at 1016, were reported as winds from 090 degrees at 4 knots, visibility 10 statute miles, overcast skies at 6,500 feet, and ceiling broken at 2,600 feet. At 1053, the weather was reported as wind from 120 degrees at 7 knots, visibility 9 statue miles, overcast skies at 5,500 feet, and ceiling broken at 3,800 feet. AIRCRAFT INFORMATION An examination of the airplane's logbooks revealed that the most recent annual inspection was completed on August 12, 2003, at a total time of 5,923.6 hours. WRECKAGE AND IMPACT INFORMATION The wreckage came to rest on private property, fragmented along rolling terrain, with brush and trees, at a field elevation of approximately 1,400 feet. The wreckage was scattered along a linear path that was 835 feet long by 260 feet wide, and oriented on a magnetic heading of 320 degrees. The initial debris field was located at the top of a hill, located 690 feet from the initial impact point. Located at the initial debris field was the outboard section of the left wing, which included the tip and a section of left aileron, a mid-section of left wing and partially attached flap, landing gear, right horizontal stabilizer, right cabin door, and a piece of the windshield. Paint transfer marks from the left wing were found on the right horizontal stabilizer. Scattered along the path from the initial debris field to the initial impact point was a section of the right elevator, left elevator tip, elevator trim tab, inboard section of the right elevator, sun visor, windshield with compass holder, rudder, a piece of the vertical stabilizer, and the rudder weight. Examination of trees located along the debris field revealed no impact damage except from falling debris. The initial impact point was a small crater that was approximately 1-2 feet deep. All three propeller blades, the piston dome and propeller spinner were separated from the engine and were embedded in the crater. The first propeller blade had separated, and was wrinkled with heavy rubbing on the non-cambered side. The second blade was bent at a 40-degree angle toward the non-cambered side, and was wrinkled at the tip and loose at the hub. The third blade exhibited heavy rubbing on the leading edge and non-cambered side. Slight twisting towards the direction of rotation was observed. The right wing tip was intact and approximately 5-6 feet from the impact point. The main wreckage, which included the firewall, cockpit area, right wing, carry thru spar and portion of the left wing spar, and empennage, were located about 80 feet forward of the initial impact point and sustained post impact fire damage. The right wing was found intact, and slightly deformed. The inboard section of the left wing was still attached to the fuselage. Examination of the electrical and vacuum attitude indicator, and directional gyro housings revealed the internal wall of their respective cases exhibited scoring. The flaps and landing gear were found in the retracted position. The engine was located approximately 10 feet to the left of the main wreckage. The accessories had separated, except for the vacuum pump, fuel pump, and fuel manifold. Most of the intake and exhaust pipes were separated and the oil sump was pushed up into the engine. The oil filter screen was absent of debris. The oil cap for the oil filler was missing. All left side valve covers were shattered and the left side cylinder heads exhibited impact damage. The vacuum pump was in place, and showed little impact damage. The drive shaft rotated freely. The unit was disassembled and the rotor-drum had two cracks and the vanes were intact. The fuel pump exhibited impact damage, and was free to rotate. The drive coupling was intact. The fuel manifold was intact and disassembled. The diaphragm and spring were in place and not damaged. The fuel screen was absent of debris, and small amount of fuel was noted. The fuel selector valve was found in the left tank position. The #1, 3, and 5 spark plugs were intact. The #2,4, and 6 spark plugs were broken in half , light gray in color, and exhibited light deposits on the electrode area. Both magnetos and their respective harnesses had separated from the engine and were impact damaged. Both magnetos were free to rotate, but no spark could be produced. MEDICAL AND PATHOLOGICAL INFORMATION MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot on February 23, 2004, by the Bexar County Medical Examiner's Office, San Antonio, Texas. Toxicological tests were performed by the FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma. Test results revealed 0.117 (ug/ml, ug/g) Hydrocodone detected in the liver. Hydrocodone was also detected in the kidney. Examination of the pilot's medical records revealed that he was treated on February 17, 2004, for acute bronchitis and was prescribed a prescription medication, Atuss MR, that contained pyrilamine, phenylephrine, and hydrocodone. Hydrocodone is a pain killer. Pyrilamine is an antihistamine with sedative side effects. ADDITIONAL INFORMATION According to the FAA Flight Training Handbook, Advisory Circular (AC) 61-21A, page 9, "The flight attitude of an airplane is generally determined by reference to the natural horizon. When the natural horizon is obscured, attitude can sometimes be maintained by reference to the surface below. If neither horizon or surface references exist, the airplane's attitude must be determined by artificial means - an attitude indicator or other flight instruments. Sight, supported by other senses such as the inner ear and muscle sense, is used to maintain spatial orientation. However, during periods of low visibility, the supporting senses sometimes conflict with what is seen. When this happens, a pilot is particularly vulnerable to spatial disorientation. Spatial disorientation to a pilot means simply the inability to tell "which way is up." According to an FAA Instrument Flying Handbook, AC 61-27C (Section II, "Instrument Flying: Coping with Illusions in Flight"), an illusion or false impression occurs when information provided by sensory organs is misinterpreted or inadequate and that many illusions in flight could be created by complex motions and certain visual scenes encountered under adverse weather conditions and at night. It also stated that some illusions may lead to spatial disorientation or the inability to determine accurately the attitude or motion of the aircraft in relation to the earth's surface. The AC further stated that the most hazardous illusions that lead to spatial disorientation are created by information received from motion sensing systems, which are located in each inner ear. The AC also stated that the sensory organs in these systems detect angular acceleration in the pitch, yaw, and roll axes, and a sensory organ detects gravity and linear acceleration and that, in flight, the motion sensing system may be stimulated by motion of the aircraft alone or in combination with head and body movement. The AC listed some of the major illusions leading to spatial disorientation as follows: "The leans - A banked attitude, to the left for example, may be entered too slowly to set in motion the fluid in the 'roll' semicircular tubes. An abrupt correction of this attitude can now set the fluid in motion and so create the illusion of a banked attitude to the right. The disoriented pilot may make the error of rolling the aircraft back into the original left-banked attitude or, if level flight is maintained, will feel compelled to lean to the left until this illusion subsides. Coriolis illusion - An abrupt head movement made during a prolonged constant-rate turn may set the fluid in more than one semicircular tube in motion, creating the strong illusion of turning or accelerating, in an entirely different axis. The disoriented pilot may maneuver the aircraft into a dangerous attitude in an attempt to correct this illusory movement.... Graveyard spiral - An observed loss of altitude in the aircraft instruments and the absence of any sensation of turning may create the illusion of being in a descent with the wings level. The disoriented pilot may pull back on the controls, tightening the spiral and increasing the loss of altitude. Inversion illusion - An abrupt change from climb to straight-and-level flight can excessively stimulate the sensory organs for gravity and linear acceleration, creating the illusion of tumbling backwards. The disoriented pilot may push the aircraft abruptly into a nose-low attitude, possibly intensifying this illusion. Elevator illusion - An abrupt upward vertical acceleration, as can occur in a helicopter or an updraft, can shift vision downwards (visual scene moves upwards) through excessive stimulation of the sensory organs for gravity and linear acceleration, creating the illusion of being in a climb. The disoriented pilot may push the aircraft into a nose low attitude. An abrupt downward vertical acceleration, usually in a downdraft, has the opposite effect, with the disoriented pilot pulling the aircraft into a nose-up attitude...." The AC also stated that these undesirable sensations cannot be completely prevented but that they can be ignored or sufficiently suppressed by pilots' developing an "absolute" reliance upon what the flight instruments are reporting about the attitude of their aircraft. The airplane was released on March 15, 2004, to a representative of the airplane owner's insurance company.

Probable Cause and Findings

The pilot's continued flight into known adverse weather and failure to maintain control of the airplane while maneuvering in instrument meteorological conditions, due to spatial disorientation.

 

Source: NTSB Aviation Accident Database

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