Aviation Accident Summaries

Aviation Accident Summary SEA94FA004

HEBER CITY, UT, USA

Aircraft #1

N50TH

CESSNA 182P

Analysis

THE PILOT ENTERED A BOX CANYON WHILE GIVING A SCENIC RIDE TO RELATIVES. THE AIRCRAFT HAD INSUFFICIENT PERFORMANCE TO OUTCLIMB THE CANYON GRADIENT. THE PILOT ATTEMPTED TO ADJUST THE POWER, AND THEN ADVISED HIS PASSENGERS THAT THEY WERE GOING DOWN. THE AIRCRAFT BURNED AFTER CRASHING ON A STEEP SLOPE, AND STARTED A FOREST FIRE. THE PASSENGERS SUSTAINED SERIOUS BURNS WHILE ATTEMPTING TO ESCAPE. ONE PASSENGER WAS TRAPPED IN THE FIRE UNTIL HIS SEAT BELT BURNED THROUGH. NO EVIDENCE OF MECHANICAL MALFUNCTIONS WAS FOUND DURING THE INVESTIGATION. THE AIRCRAFT WAS AT OR NEAR GROSS WEIGHT AT THE TIME OF THE CRASH.

Factual Information

HISTORY OF FLIGHT On October 3, 1993, approximately 1230 mountain daylight time, a Cessna 182P, N50TH, was destroyed when it collided with terrain in Center Canyon, about eleven miles southeast of Heber City, Utah. The Airline Transport Pilot was fatally injured, and his three passengers sustained serious injuries in the crash and post-crash fire. There was no flight plan filed for the personal flight, conducted under 14 CFR 91. Visual meteorological conditions prevailed at the time of the accident. The post-crash fire started a forest fire that consumed about 150 acres. The pilot had topped off with 31.4 gallons of 100 octane fuel at Heber Valley airport, and was taking relatives for a scenic flight prior to his return home in Boulder, Colorado. Airport personnel observed a forest fire to the southeast after the pilot's wife expressed her concern about the time since departure. An inbound aircraft was contacted, and it flew over the crash site. One of the injured passengers walked out to find rescue personnel. The wreckage was located near the floor of a box canyon, heading upslope toward the origin of the canyon. Other than the surviving passengers, there were no witnesses to the crash. Several people reportedly saw an aircraft low in Daniel's Canyon about the time of the accident. In an interview conducted in the hospital, the female passenger stated that her uncle in the seat beside her extracted himself after the impact, then assisted her, and they attempted to extract her other uncle who had been in the front seat. They were able to extract him after his seat belt burned through. She stated that fire had started after impact, immediately overcoming the pilot. During that interview, the female passenger said that she recalled the aircraft bouncing three times before it stopped. She stated that she observed no sputtering or other indication of a loss of power prior to the crash. She said that they had been in the canyon for about three minutes. She observed that the trees kept getting closer and closer, and that the pilot was manipulating the power controls and mumbling prior to telling the passengers to brace themselves for impact. An FAA inspector's record of interview is attached, which includes his observation that she stated that the engine was running all right, and that her uncle in the back seat with her said that something was wrong because they were too close to the trees. During a telephone interview, the front seat passenger, who sustained head injuries as well as burns, stated that he was unable to escape until the seat belt (which he stated was wrapped around his foot after the crash) burned through. He stated that they had been following the highway, then headed up a canyon. He said it seemed like the aircraft "was running out of gas," and the pilot reached down to the middle (engine) controls and adjusted them. At that time, he stated that the pilot repeatedly said "Oh, no." The passenger said that the airplane didn't have enough power, that perhaps it could have made it with a lighter person on board. On October 12, 1993, an FAA inspector interviewed Guy Nielson, who stated that they weren't very low until the aircraft started losing altitude and getting closer to the trees. He said that he did not know anything about little airplanes, but thought that the engine sputtered two or three times. He said that the pilot was pushing and pulling something on the dash trying to keep the aircraft up. None of the passengers provided written statements until they were solicited through their attorney. The attached passenger statements from Guy Nielson and Raymond Nielson were received in May, 1994. In that statement, Guy Nielson, who stated he was in the back seat behind the pilot, noted that "The engine began sputtering. Brent's adjusting seemed to make it surge, then sputter. All passengers were quiet with concerned looks. We were losing altitude because I could see the trees and mountains coming closer. The engine sputtering got worse, we dropped below the ridge on our left, then down right next to the trees. I looked at Shanna next to me and said 'Brace yourself, we're going to crash.'" Raymond Nielson, in his statement provided in May 1994, stated that "The engine started cutting out. The pilot kept on trying things like adjusting the controls, and we were losing altitude. He steered into this valley for more air time to correct the problem, and find a level spot to try and land." INJURIES TO PERSONS The three passengers received injuries during the crash, and received serious burns while attempting to escape from the burning aircraft, requiring extensive hospitalization. PERSONNEL INFORMATION The pilot was a first officer for a major airline, and held type ratings in Convair 340/440, and BAE-146 aircraft. He had commercial pilot privileges in single-engine aircraft, and held a current certified flight instructor certificate. According to FAA medical records, his weight was 162 pounds on September 22, 1992. According to driver's license information, Ms. Rivera's weight was 120 pounds; Raymond Nielson's weight was 185 pounds. In their written statements, Raymond Nielson stated that his weight was 178 pounds; Guy Nielson stated that he weighed between 165 and 170 pounds at the time of the accident. AIRCRAFT INFORMATION Empty weight of the aircraft was recorded as 1854 pounds on February 13, 1992; useful load was 1096 pounds, CG was 38.1, and maximum gross weight was 2950 pounds. The aircraft was equipped with a Robertson STOL installation, and with 80 gallon total fuel capacity, with 5 gallons unusable fuel. METEOROLOGICAL INFORMATION Weather observations for stations in the vicinity of Heber City are attached. WRECKAGE AND IMPACT INFORMATION The crash site was about three miles up Center Canyon, at 43 degrees 15 minutes north, 111 degrees 16 minutes west. The impact scatter was along a heading of 080 degrees, across the slope of a boulder field. The first evidence of ground contact was portions of the left wing tip navigation light fairing, 96 feet from the main wreckage. Separate pieces of propeller blades, at 60 and 50 feet from the main wreckage, bracketed an impact crater in the boulders. One blade tip was a section of about 4 to 5 inches, which exhibited chordwise and diagonal gouging, and extensive leading edge damage. The second blade section was about eight inches long, and exhibited extensive leading edge damage. The left wing strut was 17 feet, and upslope slightly, from the main wreckage. The right wing strut and right wing were slightly downslope of the main wreckage. The empennage and what remained of the fuselage tailcone were oriented on a heading of 220 degrees. The slope gradient was measured as 25 degrees. The left main landing gear wheel was at the bottom of the boulder field, downslope of the left wing strut. Small pieces of plexiglass, strobes, and other wreckage were in the scatter path between the main wreckage and the evidence of first ground contact. Post-crash fire consumed about 150 acres of forest. The fuselage was consumed by fire damage forward of the vertical fin to the firewall. The right wing was folded upward about four feet inboard of the wingtip, and was mostly consumed by fire inboard of the strut. The left wing was consumed by fire inboard of the strut, and its outer panel showed evidence of upward folding and displacement, midspan on the aileron. The nosewheel and a portion of the strut were detached from the rest of the airframe. The only instrument recovered was the altimeter, which recorded 6920 feet, with a Kollsman reading of 30.28. The cockpit engine controls were all forward. The fuel selector was melted free of the airframe, and was determined to be positioned at both. The flaps were determined to be in the up position. The elevator trim tab was about 5 degrees up. Control cable continuity was established from the tailcone to the cabin area. One propeller blade exhibited leading and trailing edge gouging. The other propeller blade also exhibited leading and trailing edge gouging, and spanwise gouging. Both blades were bent aft around the engine cylinders. The engine showed evidence of burn damage. The accessories were burned or melted; the vacuum pump was off, its rotor was recovered and found to be intact, with some of the vanes intact. The housing was broken and not scored. The exhaust was crushed. The muffler was removed and the inside of the muffler checked for blockage, with none being found. The carburetor butterfly was found in the closed position and the mixture control was at midpoint, with the cables stretched. On site inspection of the engine included removal of five bottom spark plugs (1,2,3,4, 5) and number 6 top spark plug. All showed evidence of fire damage. Center electrodes showed little erosion, and there was no evidence of lead fouling. Number 4 was oil soaked. The magnetos were destroyed by fire. TESTS AND RESEARCH The operator of the refueling facility retained a fuel sample for testing immediately after he became aware of the accident. His supplier inspected the fuel visually, and stated that it good and did not require further testing. The engine was inspected and partially disassembled at a salvage facility at Greeley, Colorado. The crankshaft could be rotated by hand. All of the valve train operated normally, with thumb compression evident on four cylinders. Drive train continuity was established through the drive train to the magneto drive gears. Number six cylinder was removed for inspection; no anomalies were noted. The oil filter was split. It showed evidence of heat damage, but no contamination was noted. No contamination was found in the carburetor screen. The carburetor was disassembled. The mixture control was in an approximate mid-range, and the accelerator pump seal appeared intact and undamaged. The butterfly vale had heavy soot on the bottom side, but was comparatively clean on the top. The float had heat damage, with melted solder. ADDITIONAL INFORMATION The wreckage was released to the insurance adjuster, who stated that he was the owner's representative, on October 20, 1993. The airframe remained at Spanish Forks Flying Service, and the engine was at Beagle Aircraft, Greeley, Colorado.

Probable Cause and Findings

THE PILOT'S IMPROPER INFLIGHT DECISIONS AND FAILURE TO MAINTAIN PROPER ALTITUDE. FACTORS INCLUDE THE BOX CANYON.

 

Source: NTSB Aviation Accident Database

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