Aviation Accident Summaries

Aviation Accident Summary WPR10FA459

Coeur d'Alene, ID, USA

Aircraft #1

N111NA

CESSNA T210N

Analysis

During a cross-country flight, the airplane collided with mountainous terrain at an elevation of 3,300 feet mean sea level (msl). Radar data initially identified the flight at 12,000 feet msl on a direct path to the pilot’s planned destination. About 20 miles southeast of the airport, the track indicated a descending left turn to the west-southwest followed by multiple 360 degree turns. The track then proceeded northeast over mountainous terrain, climbing and descending between 3,300 and 3,600 feet msl. The track indicated multiple 180-degree turns before the radar data terminated in the general vicinity where the wreckage was located. Around the time of the accident, reported weather at the destination airport (14 miles north) included cloud layers at 3,900 feet and 6,500 feet. The pilot did not hold an instrument rating, and it is likely that he was maneuvering around weather when the collision occurred. The pilot did not obtain a flight service station (FSS) weather briefing for the flight. A postaccident examination of the airframe and engine revealed no evidence of preimpact mechanical failures or malfunctions.

Factual Information

HISTORY OF FLIGHT On September 17, 2010 about 1400 Pacific daylight time, a Cessna T210N, N111NA, sustained substantial damage after impacting terrain about 14 miles south of Pappy Boyington Field Airport (COE), Coeur D’Alene, Idaho. The airplane was being operated as a visual flight rules (VFR) cross-country flight under the provisions of Title 14 Code of Federal regulations (CFR) Part 91. The private pilot and passenger were fatally injured. The personal cross-country flight departed South Big Horn County Airport (GEY) Greybull, Wyoming, about 1000 Pacific daylight time with a planned destination of COE. Visual meteorological conditions prevailed, and no flight plan was filed. Federal Aviation Administration (FAA) radar data showed a flight track, accompanied with mode C altitude transmissions, which were consistent with the accident airplane’s planned route of flight. The radar data showed a track attributed to the airplane about 20 miles southeast of COE at 12,000 feet mean sea level (msl). The track made a left turn towards the west-southwest and began a descent. The track then started a descending 360 degree turn to the left, followed by a 360 degree turn to the right. While descending through about 4,500 feet, the track departed the right 360 degree turn to the northeast. The radar track climbed and descended between 3,300 feet msl and 3,600 feet msl until 1351, when the radar track turned right 180 degrees to the southwest. The track then climbed and turned to the north towards the airport; a final 180 degree turn was initiated towards the south at 4,600 feet just before the radar data terminated at 1357. PERSONNEL INFORMATION At the time of the accident, the pilot, age 50, held a private pilot certificate with airplane single engine land privileges that was issued on April 26, 2010. The pilot did not hold an instrument rating; his most recent FAA third class medical was issued on January 27, 2010; no limitation or waivers were noted. Examination of the pilot’s logbook revealed that he had accumulated approximately 352 hours of flight experience, 277 hours of which were in the accident airplane. AIRCRAFT INFORMATION The accident airplane, a Cessna T210N, serial number 21063284, was manufactured in 1979 and was equipped with a Continental TSIO-520 engine. The airframe and engine maintenance logbooks were not located. Fuel records at GEY established that the airplane was last fueled on September 6, 2010 at two different times. The airplane was serviced with 21 gallons of avgas (100 Low Lead) at 0715 and 48 gallons of 100LL at 1230. METEOROLOGICAL INFORMATION The nearest weather reporting station was at COE about 14 miles north of the accident site, at an elevation of 2,320 feet. At 1355, the weather was reported as wind from 030 degrees at 14 knots, visibility 10 statute miles, scattered clouds at 3,900 feet, broken clouds at 6,500 feet, temperature 14 degrees Celsius (C), dewpoint 10 degrees C, and an altimeter setting of 30.00 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The wreckage was located in mountainous terrain about 3,300 feet msl. The area was heavily wooded and the terrain angle was approximately 30-45 degrees. The first identified point of contact was a topped conifer tree. The debris path continued down-slope approximately 520 feet in length from the conifer tree to the last known piece of debris. The airplane’s right wing followed the initial impact point; the wing was separated from the fuselage and was located about 350 feet from the conifer tree. Leading edge aft crushing and deformation was noted throughout. Approximately 34 feet downhill from the wing, was a large impact crater that contained two of the three propeller blades. The blades were broken away from the hub assembly and buried in the crater. The fuselage and main wreckage were located in a tree, about 35 feet above the ground, down slope from the impact crater. The left wing and engine were separated from the fuselage and located just beyond the main wreckage. The last known item in the debris field was the airplane’s starter, which was located about 75 yards down slope of the aforementioned tree. MEDICAL AND PATHOLOGICAL INFORMATION The Spokane County Medical Examiner completed an autopsy on the pilot. The cause of death was reported as blunt force injuries. The FAA Civil Aerospace Medical Institute (CAMI) completed toxicology testing on specimens from the pilot. The results were negative for ethanol and drugs; testing for carbon monoxide and cyanide were not performed. The passenger’s results were negative for carbon monoxide, cyanide, ethanol and controlled substances. TEST AND RESEARCH The airplane was recovered from the accident site to a storage facility and later examined by the National Transportation Safety Board (NTSB) Investigator-in-Charge (IIC), an FAA inspector and representatives of the engine and airframe manufacturers. Engine Visual inspection of the recovered engine revealed no visual anomalies. The cylinder rocker covers and spark plugs were removed; the spark plug electrode areas were consistent with, worn out – normal, when compared to the Champion AV-27 chart. The cylinders were borescoped. The piston head and combustion areas were undamaged; organic debris was noted within the cylinders. The valves were undamaged and contained no abnormal thermal discoloration. Cylinder compression and valve continuity was obtained from all cylinders. The magnetos sustained impact damage. The drive shafts were rotated by hand and the impulse couplings engaged for both magnetos, however, there was no spark generated from either magneto. The magnetos were disassembled and no anomalies were noted beyond the external damage that was consistent with impact forces. The fuel manifold valve had separated from the engine during the impact sequence. The valve was disassembled; the screen and diaphragm were intact and clear of debris, fuel was present in the plunger area. The screen was clear of debris. The fuel nozzles were undamaged and no obstructions were noted. Airframe The airframe was fragmented and extensive impact related damage was noted throughout. All flight control surfaces were located along the debris path. The forward section of the fuselage and cockpit were crushed aft and a majority of the cockpit instrumentation and components were severely fragmented and crushed. Examination of the airframe and engine revealed no evidence of preimpact mechanical failures or malfunctions that would have precluded normal operations.

Probable Cause and Findings

The pilot’s continued flight into instrument meteorological conditions and failure to maintain clearance with mountainous terrain while maneuvering in an area of low cloud ceilings.

 

Source: NTSB Aviation Accident Database

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