Aviation Accident Summaries

Aviation Accident Summary LAX08FA256

Gearhart, OR, USA

Aircraft #1

N828CC

CESSNA 172K

Analysis

The pilot took off in the morning without filing a flight plan for the planned cross-country flight. Weather in the vicinity of the airport was less than 3 miles visibility with overcast clouds at 300 feet above ground level. The overcast layer extended from 300 feet to 2,600 feet. Aircraft flight data was recovered from a handheld GPS unit that was onboard the airplane. The data disclosed that the airplane climbed to 412 feet mean sea level (msl) on a northerly heading, then entered a climbing left-hand turn that tightened into a climbing spiral. The airplane reached 1,350 feet msl before entering a rapid spiraling descent and colliding with a vacation home about 1 mile northwest of the airport. These GPS flight track data suggested that the pilot may have become spatially disoriented during the initial climb. A post impact fire destroyed the house and airplane. The pilot held an instrument airplane rating; however, a review of his personal flight records was unable to establish that he was current with his instrument flight experience. The majority of the airplane was destroyed by the post impact fire. In the small portions of wreckage that could be examined, no mechanical anomalies were identified. Post-accident toxicology testing detected a low level of zolpidem, a prescription sleep aid often known by the trade name Ambien, in the blood of the pilot. The source from which the blood sample was taken was not documented, however, and no conclusive determinations can be made regarding when the pilot may have last used the medication or whether he may have been impaired by its use. The medication would not typically be expected to result in impairment more than 6 hours after a dose, and the U.S. military permits flight duties as soon as 6 hours after the use of zolpidem.

Factual Information

HISTORY OF FLIGHT On August 4, 2008, at 0648 Pacific daylight time, a Cessna 172K, N828CC, impacted a small neighborhood residence in Gearhart, Oregon. The airplane was operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The commercial pilot, his passenger, and three people on the ground were killed, three people on the ground were seriously injured, and the airplane was destroyed. Instrument meteorological conditions prevailed, and no flight plan had been filed. The flight originated at Seaside Municipal Airport, Seaside, Oregon, around 0644. The pilot rented the airplane from an operator at Seaside Municipal Airport the night before the accident. The operator stated that the pilot told him that he was making a business trip to Klamath Falls, Oregon, in the morning. Global positioning system (GPS) data recovered from a handheld GPS unit located in the airplane recorded that the takeoff occurred at 0644. The airplane climbed to about 412 feet mean sea level (msl) on a northerly heading, then entered a climbing left-hand turn that tightened into a spiral over the beach. The airplane climbed to 1,350 feet msl then entered a rapid descent at 0646:31. The final GPS data point occurred at 0646:39, at an altitude of 832 feet msl. The airplane collided with a vacation home in Gearhart, about 1 mile northwest from the Seaside Municipal Airport. The airplane appeared to have been traveling in a northerly direction when it first impacted a large pine tree, and then into the house. A post impact fire erupted and destroyed the house. PERSONNEL INFORMATION The pilot, age 36, held a commercial pilot certificate, issued on September 11, 2003, with single-engine land and instrument airplane ratings. Additionally, he held a certified flight instructor (CFI) certificate, single-engine land, issued on August 4, 2006. He held a second-class airman medical certificate, with no limitations, that was issued on June 24, 2008. The pilot’s logbook was not located during the course of the investigation. The pilot noted on his June 24, 2008, medical application a total pilot time of 1,650 flight hours. The owner of the airplane stated that he had given the pilot a flight review on June 27, 2008, in which he reviewed Cessna 172 operations, engine failures, GPS familiarization, and crosswind landings. They did not fly any practice instrument flight using a hood. A review of the pilot’s available flight records could not establish the existence of recent instrument flight experience or currency. Federal Aviation Administration Regulations, Part 61.57, states that no person may act as pilot-in-command under instrument flight rules (IFR) or in weather less than the minimum prescribed for visual flight rules (VFR), unless within the preceding 6 calendar months, that person has logged at least 6 instrument approaches, holding procedures, and intercepting and tracking courses through the use of navigation systems. AIRCRAFT INFORMATION The four-seat, high-wing, fixed-gear, single-engine airplane, was manufactured in 1969. It was powered by a Lycoming O-360-1A1, 150 horsepower engine, and equipped with a Hartzell model HC-C2YK-1BF constant speed propeller. Review of the airplane’s maintenance records revealed that an annual inspection was performed on the airframe and engine on April 1, 2008. The annual inspection documentation shows that the total time on the airplane was 3,650 hours, and the engine’s total time since overhaul (TTSOH) was 1,198 hours. The propeller annual inspection was also documented as performed on April 1, 2008. The operator provided copies of the airplane’s use log for March through July 2008. The accident pilot flew the airplane three times during that period; June 27 for 1.3 hours (BFR), July 23 for 2.0 hours, and July 24 for 2.0 hours. Additionally, he noted that he (the operator) had flown an instrument proficiency flight in the airplane on July 27; no instrument abnormalities were noted during the flight. The operator stated that he fueled the airplane on August 3, 2008, at Astoria Regional Airport, topping off the fuel tanks. The flight back from Astoria to Seaside took 0.2 hours. The fuel receipt from Astoria Regional Fuel Sales recorded that N828CC received 28.7 gallons of 100LL on August 3. METEOROLIGCAL INFORMATION The Automated Surface Observation System (ASOS) at the Astoria Regional Airport, located 8 miles north of the Seaside Municipal Airport, reported that the weather conditions at 0655 were calm winds; 2.5 miles visibility in mist; 300-foot overcast layer; temperature 12 degrees centigrade (C); and the dew point 12 degrees C. A former airline pilot who lived on the beach in Gearhart reported that he observed that visibility was less than 80 feet at 0600 on the morning of the accident. The 1500Z Atmospheric Model Data (NAM12) relative humidity profile shows the cloud tops were approximately 2,600 ft msl. WRECKAGE & IMPACT The airplane wreckage was in the center of a wood house structure that had been gutted and destroyed by fire. Major portions of the fuselage and tail were not located; however, deposits of melted aluminum were found in the direct area around the airplane's control cables, cockpit instruments, and engine. The right wing was located at the base of a large pine tree 115 feet south of the engine/cockpit location. Branches of freshly broken tree limbs were intermingled with debris from the airplane structure. The large pine tree was determined to be the initial point of impact. The left wing was located about 60 feet south of the engine/cockpit area. Both wings had been separated at the wing root and had semicircular deformations in their leading edges. The ailerons and flaps were attached to both wings. The left horizontal stabilizer and elevator had been separated at the stabilizer root and was located near the debris of the left wing. Flight control cable continuity was established for the elevators, and for the ailerons through multiple overload separations. The left rudder cable was continuous, from the rudder horn to the cockpit rudder bar, and the right was separated approximately 2 feet forward of the rudder horn. The flap jackscrew measurement equated to a flap retracted setting. The bearing from the tree that was identified as the initial point of impact to the engine/cockpit location was 010 degrees magnetic. The angle of impact as determined by the angle between the cockpit/engine location and the highest branch missing from the tree was 20 degrees. The propeller and crankshaft flange had separated from the engine and was located about 6 feet north of the engine. One blade tip exhibited a slight forward curl. The remaining portion of the second blade measured 12 inches from the hub. The engine exhibited thermal damage. Engine mechanical continuity was established by rotating the crankshaft and achieving thumb compression on cylinders 1, 2, and 4. The number 3 cylinder’s valve push rods were bent, holding open a valve. Both magnetos were removed and produced spark at all posts when rotated by hand. Oil was observed to drain out of the engine. The spark plugs were removed and the electrodes were gray in color, all gaps similar, and exhibited no mechanical damage. The carburetor was removed and disassembled. Both metal carburetor floats were uniformly deformed. The plastic shear coupling on the vacuum pump was thermally damaged and deformed. The vacuum pump was disassembled; the rotor was intact, all vanes were in their slots, and all were observed as approximately the same length. The attitude gyro was disassembled; the rotor shaft was in its journals, two very light score marks were observed on one interior side of the external gyro case. Due to the thermal and mechanical damage of the engine and cockpit area, integrity of the vacuum system could not be determined. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy was performed on the pilot on August 5, 2008, by the Clatsop County Medical Examiner. Autopsy findings include blunt force trauma of the head, blunt force trauma of the chest, and postmortem charring. The cause of death was reported as massive blunt force trauma of the head. Forensic toxicology was performed on specimens collected from the pilot by the FAA Forensic Toxicology Research Team, Oklahoma City, Oklahoma. The report contained negative results for carbon monoxide, cyanide, and ethanol. The report noted “0.026 (ug/ml, ug/g) ZOLPIDEM detected in Blood; ZOLPIDEM detected in Urine.” The source from which the blood sample was taken was not noted on the autopsy report, or on the containers, packaging, or paper work accompanying the specimens. The U.S. military will permit pilots, under supervised conditions, to perform flight duties as soon as 6 hours (Navy and Air Force) and 8 hours (Army) after the use of zolpidem.A positive result for 0.026 ug/ml of zolpidem was annotated. TESTS AND RESEARCH GPS A Garmin GPSMAP 295, a hand portable GPS unit, was recovered at the accident location. The unit was sent to the Safety Board’s Vehicle Recorder Laboratory for data recovery. The data was downloaded using Garmin MapSource v6.13.7. Forty-nine user defined waypoints, 10 user defined routes, and 6 tracklogs dated April 19 to August 4, 2008, were downloaded from the GPSMAP 295. One tracklog was recorded on the date of the accident. Downloaded tracklog data included the following parameters for each recorded data point: index, date, GPS time, GPS altitude, distance from previous update [leg length], time since last update [leg time], average groundspeed during period since last update [leg speed], average course during period since last update [leg course], and latitude/longitude position at the time of the update. Leg length, leg time, leg speed, and leg course information are all calculated by the download software and are not directly calculated and recorded within the GPS unit itself. Data corresponding to ACTIVE LOG 005 tracklog began at 0638:36 with a latitude/longitude position fix corresponding to Seaside Municipal Airport. The average GPS altitude during the first 5 minutes 55 seconds of recorded tracklog data was 15.5 feet. Field elevation for Seaside is 12 feet. The final GPS position location fix was recorded at 0646:39, and placed the airplane at 46 degrees 01.578 minutes north latitude and 123 degrees 55.622 minutes west longitude, with 832 ft GPS altitude – approximately 828 feet msl after correcting for local vertical GPS distance error. The last calculated velocity and direction of travel was 136 mph groundspeed with a course of 220 degrees true. The data depicts the airplane track starting on runway 34, climbing to 412 feet msl, then entering a left-hand climbing turn. The left-hand climbing turn constantly reduces in radius, creating a path consistent to an inward spiral. At 1,350 feet the airplane enters a rapid descent of approximately 3,885 feet per minute. The GPS Factual Report is contained in the official docket of this investigation. ADDITIONAL INFORMATION Spatial Disorientation The Instrument Flying Handbook (FAA-H-083-15A) defines spatial disorientation as " the lack of orientation with regard to position in space and to other objects." "A pilot in a prolonged coordinated, constant rate turn, will have the illusion of not turning. During the recovery to level flight, the pilot will experience the sensation of turning in the opposite direction. The disoriented pilot may return the aircraft to its original turn. Because an aircraft tends to lose altitude in turns unless the pilot compensates for the loss in lift, the pilot may notice a loss of altitude. The absence of any sensation of turning creates the illusion of being in a level descent. The pilot may pull back on the controls in an attempt to climb or stop the descent. This action tightens the spiral and increases the loss of altitude; hence, this illusion is referred to as a graveyard spiral. At some point, this could lead to a loss of control by the pilot." (FAA-H-083-15A)

Probable Cause and Findings

The pilot's failure to maintain aircraft control during the initial climb after takeoff due to spatial disorientation.

 

Source: NTSB Aviation Accident Database

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