Aviation Accident Summaries

Aviation Accident Summary FTW04FA208

Burnet, TX, USA

Aircraft #1

N927RP

Piper PA-32-300

Analysis

The non-instrument rated pilot lost control of the airplane due to spatial disorientation after entering into instrument meteorological conditions while en route to his destination. He had obtained three separate weather briefings from a flight service station that reported a stationary front with high clouds over the intended route of flight. An air traffic control center first plotted the airplane ascending through 5,000 feet. After reaching an altitude of 10,000 feet, the airplane began to descend in a tight right turn losing altitude rapidly, with the last radar contact at 7,500 feet. A witness reported seeing an airplane coming out of the clouds and diving at a very high rate of speed. Pieces of the airplane were found scattered up to a half-mile distance from the main wreckage site.

Factual Information

HISTORY OF FLIGHT On August 7, 2004, approximately 1700 central daylight time, a Piper PA-32-300 single-engine airplane, N927RP, was destroyed upon impact with terrain following a loss of control and subsequent in-flight breakup while maneuvering near Burnet, Texas. The non-instrument rated private pilot and passenger were fatally injured. The airplane was owned and operated by the pilot. Instrument meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 91 personal flight. The flight originated from Horseshoe Bay Airpark (4XS7), near Marble Falls, Texas, approximately 1610, and was destined for Lubbock, Texas. Air traffic control (ATC) from Houston Center stated that there were no communications with the pilot, and there were no distress calls received from the pilot. The airplane impacted terrain and came to rest in a remote area of Burnet County, approximately 32 statute miles (SM) northwest of 4XS7. A witness to the accident reported that she was looking upwards over a tree line, approximately 15-20 feet in height and approximately 70-80 feet away, when she first saw an object that appeared to look like an airplane coming out of the clouds and diving at a very high rate of speed. She recalls, "the weather was overcast and somewhat windy." The witness also stated that there was no smoke or fire coming from the aircraft, and she did not remember seeing any components of the airplane breaking apart. She added that the airplane disappeared behind a line of trees, and she did not see the airplane come back up, nor did she hear the sound of an impact. According to tape recordings submitted by the San Angelo Flight Service Station (FSS), the pilot received three weather briefings prior to departure from 4XS7. On the first briefing, the pilot told the FSS that he planned a 1200 departure, with a cruising altitude of 8,500 feet. On the second briefing, the pilot estimated a 1530 departure, with a cruising altitude of 6,500 feet. On the last briefing, the pilot estimated a 1630 departure, with a cruising altitude of 6,500 feet. The pilot also told the FSS that the estimated time en route was two hours. According to radar data obtained from the Houston Air Route Traffic Control Center (ARTCC), the airplane was first plotted approximately 1642 traveling on a north-northwesterly heading, steadily ascending through 5,000 feet. The airplane then began to turn to a northeasterly heading at 1654, reaching an altitude of 10,000 feet at 1656:22. From the northeasterly heading, the airplane began to descend in a tight right turn. Radar data depicted the airplane at an altitude of 9,700 feet at 1656:43, and an altitude of 7,700 feet at 1657:23. The last contact that the radar depicted was 7,500 feet at 1657:13. PERSONNEL INFORMATION The 44 year-old pilot was issued a private pilot certificate with an airplane single-engine land rating on March 16, 2004. The pilot possessed a third class medical certificate, with no limitations, that was issued on September 30, 2003. No personal flight records were located for the pilot and the aeronautical experience listed in this report was obtained from a review of the airmen FAA records on file in the Airman and Medical Records Center located in Oklahoma City, Oklahoma. These records indicated a total of 16 hours of flight time when the last medical certificate was issued. AIRCRAFT INFORMATION The airplane was a low wing 1973-model Piper PA-32-300, configured for a maximum of six seats, serial number 32-7340152, which the pilot purchased on December 12, 2003. According to the aircraft logbook, the most recent annual inspection was completed on March 18, 2004, at an airframe total time of 3,451.1 hours. The total airframe time recorded on the Hobbs meter and tachometer at the time of the accident could not be retrieved due to impact damage. The airplane was powered by a Textron Lycoming IO-540-KIA5 engine, serial number L-11978-48, rated at 300 horsepower. According to the engine logbook, the engine was last overhauled on June 9, 1988, with a recorded tachometer time of 2,068 hours. The most recent annual inspection was completed on April 1, 2004, with the engine total time as 3,562.5 hours, thus indicating 1,494.50 hours since an overhaul. The Hartzell model HC-C2YK-1 propeller assembly, serial number CH21704, received a 100-hour inspection on March 18, 2003. According to maintenance records, the assembly was last overhauled on September 29, 1993, with a tachometer time of 2,068 hours. Examination of the maintenance records revealed no unresolved maintenance discrepancies against the airplane prior to departure. Fueling records from Horseshoe Bay Airpark established that the airplane was fueled on August 5, 2004, with the addition of 34.4 gallons of 100-octane aviation fuel. At the request of the NTSB investigator-in-charge (IIC), a fuel sample was taken by airport personnel on August 9, 2004, and no anomalies were noted. METEOROLOGICAL INFORMATION At 1653, the Automated Surface Observing System (ASOS) at the Burnet Municipal Airport-Kate Craddock Field (KBMQ) near Burnet, Texas, located approximately 18 miles from the accident site, reported: wind variable at 3 knots, visibility 9 statute miles, sky condition overcast at 4,300 feet, temperature 29 degrees Celsius, dew point 19 degrees Celsius, and an altimeter setting of 29.96 inches of Mercury. A Surface Analysis Chart prepared by the National Weather Service (NWS) National Centers for Environmental Protection (NCEP) for 1600 on the day of the accident showed a stationary front located over southern-southwestern Texas. A northeast-southwest ridge of high pressure predominated over central and northeastern Texas. A visible satellite image for the nominal time of 1702 depicted a northwest-southeast line of clouds paralleling the airplane's path. The line of clouds intersected the accident area and extended further to the northwest. The image indicated thin high clouds and scattered-broken low-mid level clouds west and southwest of the accident location. Two radar products indicated a convective cell northwest of the area where the airplane disappeared from radar. Comparison of the two products revealed that the northwest cell expanded in area and increased in intensity from 20 dBZ to 35 dBZ over the 1655-1700 time period. Additionally, the cells were increasing in altitude during a time period between 1655 and 1705. A staff meteorologist for the Safety Board prepared a factual report as part of supporting documentation, which included the following for the departure area: surface weather observations, pilot reports, winds and temperatures aloft data, Geostationary Operational Environmental Satellite-12 data, National Weather Service WSR-88D data, and aviation area forecast. WRECKAGE AND IMPACT INFORMATION Investigators from the Safety Board, the Federal Aviation Administration, Piper Aircraft, and Textron Lycoming Engines examined the wreckage at the accident scene. The airplane impacted dry rocky terrain along the side of a mountain. The airplane came to rest on a magnetic heading of 100 degrees on its left side, at latitude 31.00.25 degrees North, longitude 98.25.95 degrees West. The field elevation was recorded at 1,337 feet mean sea level (msl). Components of the airplane, including the left inboard wing, flap, and landing gear, the left outboard wing and tip, the right wing tip, and the left aileron, were found scattered in a northerly direction within a half-mile distance from the main wreckage site, with other fragmented pieces located up to 70 feet from the main wreckage. Wreckage fragmentation was consistent with a high velocity ground collision after an in-flight breakup, with pieces of the bottom fuselage skin imbedded into rock formations. Pieces of the detached airplane skin exhibited 45-degree angle fractures. The left wing had an upward and aft bend five inches outboard of the connecting splice on the outboard section of the wing. One of the connecting bolts on the aft spar was missing, and the bolt hole was formed into an oblong pattern. All cockpit communication and navigation aids, electrical switches, flight instruments, engine instruments, and cockpit engine controls were destroyed. The pilot's seatbelt was found connected, but not attached to its respective mounts. The propeller governor screen and governor oil line were destroyed. One propeller blade was observed partially twisted and bent. The other blade displayed a greater degree of twist and bending, including leading edge gouging and scratches along the chord wise axis. The engine, with most of its components and accessories, was destroyed, including the fuel nozzles and fuel pump, and vacuum pump. The ignition system, including starter, alternator, and environmental controls were destroyed, except for part of the left magneto. No anomalies with the engine were noted. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed by the Medical Examiner's Office of Travis County on August 8, 2004. It was determined that the pilot's death was a result of multiple traumatic injuries sustained in the airplane crash. A toxicological test was performed by the FAA's Civil Aeromedical Institute (CAMI) in Oklahoma City, Oklahoma, for volatiles and drugs. The result of the tests were negative for alcohol and all screened drug substances. FIRE There was no evidence of an in-flight fire or significant post-impact fire found during the on-scene portion of the investigation. TESTS AND RESEARCH On August 24, 2004, the NTSB IIC and representatives from Textron Lycoming Engines and Piper Aircraft met at Air Salvage of Dallas (ASOD) in Lancaster, Texas, to reexamine the airplane wreckage. Due to the remote crash site location and terrain, further examination was made after the airplane was recovered by ASOD. However, further examination did not reveal anomalies not already observed. ADDITIONAL INFORMATION According to the FAA Advisory Circular (AC) 61-21A, "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 nor 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." The FAA AC 61-27C (Section II, "Instrument Flying: Coping with Illusions in Flight") states that spatial disorientation cannot be completely prevented, but it be ignored or sufficiently suppressed by pilots' developing an "absolute" reliance upon what the flight instruments are reporting about the attitude of their aircraft. For more information, including descriptions of the major illusions leading to spatial disorientation, see the FAA AC 61-27C. The wreckage was released to the owner's representative on August 24, 2004.

Probable Cause and Findings

The pilot's continued flight into known adverse weather, VFR flight into instrument meteorological conditions, and his failure to maintain control of the airplane due to spatial disorientation. A contributing factor was the cloudy weather.

 

Source: NTSB Aviation Accident Database

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