Ludlow, CA, USA
N5201F
CESSNA T182
After departing on a cross-country flight in night visual meteorological conditions, the pilot requested flight following from air traffic control. According to radar data, about 11 minutes after takeoff, the airplane leveled off at 14,800 feet mean sea level (msl). About 30 minutes later, when the airplane was still about 150 miles from its destination, air traffic controllers observed the airplane beginning to descend. When air traffic controllers subsequently questioned the pilot as to his intensions, the pilot’s responses were garbled and unintelligible. Radar data indicated that the airplane continued a meandering descent until it descended through about 11,000 feet msl and radar contact was lost. The airplane impacted terrain in a right-wing-low attitude, and the debris field extended about 830 feet. Postaccident examination revealed no preimpact mechanical malfunctions or failures that would have precluded normal operation. The investigation revealed that the pilot had flown for about 40 minutes at altitudes exceeding 12,500 feet msl, with much of that time spent at 14,600 feet msl. At these altitudes, without the use of supplemental oxygen, the pilot would have become hypoxic (insufficient brain oxygen). Although the pilot’s wife indicated that he typically used supplemental oxygen when operating above 11,000 feet msl and supplemental oxygen was available to the pilot during the flight, postaccident investigation indicated that no cockpit oxygen ports were in use when the accident occurred. The degree of hypoxia experienced by the pilot would have severely degraded his performance. Both the garbled transmissions to air traffic controllers and the airplane’s meandering flight path are consistent with the pilot experiencing symptomatic hypoxia. As the airplane descended during the last few minutes of the flight, the pilot’s oxygen saturation would have slowly improved; however, the rate of descent was likely too rapid to allow the pilot to recover his vision and judgment in time to prevent the accident.
On April 5, 2012, about 2015 Pacific daylight time, a Cessna T182T, N5201F, was substantially damaged following impact with terrain while maneuvering about 17 nautical miles (nm) northeast of Ludlow, California. The certified private pilot, who was the owner and sole occupant of the airplane, was fatally injured. Visual meteorological conditions prevailed for the personal cross-country flight, which was being operated in accordance with 14 Code of Federal Regulations (CFR) Part 91, and no flight plan was filed. The flight departed the Laughlin/Bullhead International Airport (IFP), Bullhead City, Arizona, about 1920, with its intended destination being Santa Monica Municipal Airport (SMO), Santa Monica, California. Federal Aviation Administration (FAA) voice recordings and radar data revealed that at 1925, about 5 minutes after taking off, the pilot contacted air traffic control and requested flight following. The controller responded by issuing the pilot a discrete transponder code of 1030, which the pilot acknowledged. At 1927, the controller confirmed radar contact with the flight as it was climbing westbound at an altitude of 10,000 feet mean sea level (msl). About 1929, the airplane was observed climbing through 12,500 feet msl, and at 1931, the flight leveled off at an altitude of 14,800 feet msl. It subsequently stabilized at a cruise altitude of 14,600 feet msl on a westerly heading. About 1959, the controller instructed the pilot to switch over to a second controller on a different frequency, which the pilot complied with. About 2001, the pilot contacted the second controller and advised him that he was level at 14,500 feet msl. About 45 seconds later the airplane was observed in a descent out of 14,500 feet; the pilot did not advise the controller of his intentions. About 10 minutes later at 2011, the controller queried the pilot as to whether or not he was still going to land at SMO; there was a garbled unintelligible response. About 10 seconds later the controller again asked the pilot if he was planning on landing at SMO; this was followed by a keyed microphone with the voice transmission being unintelligible. About 30 second later, at 20:12:27, the pilot radioed, “I’m having some difficulties.” This was the last recorded transmission received from the pilot. About 2009, radar data indicated that the airplane had descended through 12,000 feet msl on a southwesterly heading. About 2009:34, the airplane turned right about 30 degrees, then subsequently made another right turn to a northwesterly heading, at an altitude of about 11,400 feet msl. This was followed by a right turn to the northeast, and then another right turn to a heading of east; the airplane was now at an altitude of about 10,800 feet msl. Radar data further revealed that the airplane then made a 45-degree turn to the right to a heading of southeast and climbed to an altitude of about 11,700 feet msl, before making another right turn to a northwest heading. The last radar return, which was record at 2011:22, indicated that the airplane was at 11,000 feet msl. The airplane subsequently impacted sparse desert terrain about 1 1/2 miles northeast of the last radar position, and about 70 nm west of the departure airport. It was noted that during the flight the airplane was operated above 12,500 feet msl continually for a period of about 40 minutes, and above 14,000 feet msl for about 34 minutes. PERSONNEL INFORMATION The pilot, age 63, possessed a private pilot certificate for airplane single-engine land, which was issued on September 9, 2005. A review of the pilot’s personal logbook revealed a total time of 727 hours of flight time, of which 528 hours were logged as pilot-in-command. Additionally, the pilot had accumulated a total of 265.5 hours in the accident airplane, 260 hours of cross-country time, and 46.6 hours of night time. Further, the pilot had accumulated 18.5, 9.6, and 5.6 hours in the last 90, 60 and 30 days respectively, and about 3 hours in the last 24 hours. Also logged was 7.2 hours as simulated instrument flight time. The pilot successfully completed his most recent flight review on October 8, 2011. The pilot was issued a third-class FAA airman medical certificate on September 15, 2010, with the limitation that the pilot “must wear corrective lenses for near and distant vision.” In a conversation with a family member who had flown with the pilot in the accident airplane on various occasions, it was revealed that this was the first time he had flown to IFP. The family member stated that on cross-country flights in the past when the pilot climbed to about 11,000 feet he would use oxygen, but had a habit of not keeping the oxygen unit up front in the cockpit, and that sometimes he would have to be reminded about using it. Radar data revealed that the pilot operated the accident airplane above 12,500 feet from 0228 until 0308. There was no evidence to indicate that the pilot had used supplemental oxygen during the flight. The family member characterized the pilot as very conscientious. She also stated that he did not have very much flying experience at night. AIRCRAFT INFORMATION The airplane was a Cessna T182T, serial number T18208152. A review of the airplane’s logbooks revealed a total time on the engine and airframe of 1,269.1 hours at the most recent annual inspection, which was performed on October 4, 2011. This was the last recorded logbook entry. The engine was a Textron Lycoming TIO-540-AK1A, serial number L-11245-61A, six cylinder, air cooled, direct drive, horizontally opposed, fuel injected, internal combustion rated at 235 horse power at 2,400 revolutions per minute. METEOROLOGICAL INFORMATION The accident pilot did not request or receive a formal pre-flight weather briefing. As reported by a Senior National Transportation Safety Board (NTSB) Meteorologist in a NTSB Weather Study, the National Weather Service (NWS) 2000 Surface Analysis Chart depicted isobars near the accident site located relatively close together, which is indicative of the possibility of strong surface wind conditions. The station models around the accident site depicted winds west to northwest of 15 to 25 knots with clear skies. The meteorologist also reported that the dry, windy environment surrounding the accident site was conducive to low-level turbulence. Upper Air Charts indicated that winds were quite strong throughout the atmosphere near the accident site, with 60 knot winds at 700-hPa (10,000 feet) and winds increasing to near 100 knots at 300-hPa (30,000 feet). A Center Weather Advisory (CWA) issued by the Center Weather Service Unit in Los Angeles, California at 1840 and valid through 2040, forecasted areas of moderate to severe turbulence with areas of low-level wind shear and updrafts below 12,000 feet msl. These conditions were expected to continue through 2200; the reports were generated by light general aviation aircraft. The Area Forecast issued at 1945, forecasted clear skies and surface winds from the northwest to north at 25 knots with gusts to 35 knots. The meteorologist also reported that AIRMET TANGO was active for the accident site time, forecasting moderate turbulence below Flight Level 180 (18,000 feet) for much of the Mountain West. Geostationary Operational Environmental Satellite number 15 (GOES-15) data, which was obtained from the National Climatic Data Center, revealed that water vapor imagery at 2000 feet, showed wave-like features oriented from west to east in regular intervals from southern California into southern Utah and northern Arizona. The meteorologist noted that these wave-like features are likely due to mountain wave activity with strong westerly winds moving across the mountainous terrain, and most likely between 5,000 and 15,000 feet. At 1950, the Automated Surface Observing System (ASOS) at the Barstow-Daggett Airport (DAG), located 41 nm west of the accident site, reported wind 250 degrees at 24 knots with gusts to 35 knots, visibility 10 miles, sky clear, temperature 12 degrees Celsius (C), dew point -8 degrees C, and an altimeter setting of 29.87 inches of mercury. At 2050, the DAG ASOS reported wind 260 degrees at 30 knots with gusts to 36 knots, visibility 10 miles, sky clear, temperature 11 degrees C, dew point -7 degrees C, and an altimeter setting of 29.87 inches of mercury. For further information, refer to the NTSB Weather Study, which is located in the public docket for this accident. In a conversation with the NTSB investigator-in-charge (IIC), a pilot who was flying on an instrument flight rules (IFR) clearance at 14,000 feet msl about 20 nm in front of the accident pilot, reported that he did not recall being in any clouds during the flight, and that any turbulence was light at best. He added that there were pretty stiff headwinds. According to the U.S. Naval Observatory, Astronomical Applications Department, the phase of the moon on the evening of the accident was waxing gibbous with 98% of the Moon's visible disk illuminated. Moonrise was at 1832. WRECKAGAE AND IMPACT INFORMATION The wreckage site was located in a remote mountainous region of the Mojave Desert, which is characterized by sparse vegetation and the absence of lighted structures in the area. The main wreckage was found at coordinates 34 degrees 56.765 minutes north latitude and 115 degrees 57.455 minutes west longitude, and at an elevation of 2,424 feet msl. An examination of the wreckage revealed that the airplane had impacted terrain in a right-wing-low, high-speed impact sequence. The debris path, which extended over an area of about 830 feet on a measured magnetic heading of 170 degrees, consisted of multiple fragmented segments of the airplane; the engine was located at the terminus of the debris field. The initial impact point exhibited fragments of green navigation light lens. Thermal damage consisted of several small brush fires, the inboard left wing/fuel cell, and about a 20 feet by 20 feet area of discolored sand and rock. A large crater about 20 feet from the initial impact point, and in line with the general debris path, was indicative of remnants of the main fuselage. MEDICAL AND PATHOLOGICAL INFORMATION Medical records obtained on the pilot revealed that he first applied for FAA medical certification in 1995, at which time he reported hypertension and a history of kidney stones. His certification was initially deferred but granted after he supplied additional information. He next applied for and received third-class medical certification in 2002. At that time, and on each biannual application thereafter, the pilot denied ever having any medical problems and denied taking medication. The medical data showed that he had been taking two medications for his hypertension as well as buproprion for many years. His last third-class medical certificate was issued on September 15, 2010. The FAA Toxicology Accident Research Laboratory, located in Oklahoma City, Oklahoma, conducted toxicological testing on the pilot. Testing for carbon monoxide and cyanide was not performed. Ethanol was not detected in muscle. The following drug was detected: Bupropion detected in muscle Bupropion Metabolite detected in muscle TESTS AND RESEARCH The airframe and engine were recovered from the accident site, and examined by the NTSB IIC and representatives from Cessna Aircraft and Lycoming Engines. Airframe The left and right outboard wings were separated from the structure. The left aileron was separated from the wing and fractured at approximately mid span. An approximately 3-foot long section of the right aileron remained attached to a fragment of the outboard right wing. The left and right flaps were separated from the structure. The empennage was partially separated from the fuselage. The rudder remained attached to the vertical stabilizer. The left horizontal stabilizer was bent downward and aft. The left elevator was separated from the left horizontal stabilizer and remained in one piece. The right horizontal stabilizer was separated from the tail. An approximately 2-foot long section of the right horizontal stabilizer remained attached to the right elevator. The elevator trim tab remained attached to the right elevator. Control cable continuity was not established due to fragmentation of the wreckage. Fragments of the rudder and elevator control cables remained attached to the rudder control horn and the aft elevator bell crank. The elevator trim actuator chain, with fragments of the trim cables, remained attached to the elevator trim actuator sprocket. The left fuel cell and fuel cap exhibited fire damage. The right fuel cell was impact damaged. The fuel selector valve was disassembled and observed in the BOTH position. The nose wheel and main landing gear struts were observed fractured and separated from the airframe. A fragment of the cabin overhead containing the seat #1 and #2 oxygen ports was observed in the wreckage. The seat #1 and #2 oxygen ports did not have oxygen lines plugged into them. The locking pins inside the oxygen ports appeared normal. The seat #3 and #4 oxygen ports were also observed in the wreckage. No oxygen lines were plugged into them; the locking pins appeared normal. Two cannula type oxygen masks, with associated hoses, were observed in the recovered wreckage. One additional oxygen hose fragment, approximately 3 feet long, and a high altitude (Red) oxygen fitting (P/N C166005-0603) were observed. The locking tabs on the oxygen fitting appeared to be in a normal operable condition and were not deformed. The instrument panel was fragmented. The face of the altimeter and vertical speed indicator were recovered. There were no visually identifiable needle marks on the instrument faces. All of the seats were separated from the structure and sustained impact damage. Engine The engine was partially fragmented as a result of impact energy sustained during the collision with terrain. As a result, crankshaft rotation could not be accomplished. Mechanical continuity of the rotating group and internal mechanisms were established visually during the partial disassembly and visual examination of the engine utilizing a borescope. There was no evidence of lubrication deprivation or contamination found. There were no signatures or conditions observed consistent with any pre- accident catastrophic mechanical malfunction. The camshaft was intact and each of the camlobes appeared normal in their shape. The accessory gearbox cover was removed. The accessory gears including the crankshaft gear, bolt and dowel were intact and remained undamaged by any pre-impact malfunction. The oil pump drive was free to rotate by hand. The combustion chambers of the cylinders remained undamaged by any foreign object ingestion. The gas path and combustion signatures observed at the spark plugs, combustion chambers and exhaust system components displayed coloration consistent with normal operation and remained free of oil residue. The spark plugs had sustained varying degrees of impact energy damage. The top spark plugs were removed, examined and photographed. The spark plug electrodes remained mechanically undamaged, and according to the Champion Spark Plugs “Check-A-Plug” chart AV-27, the spark plug electrodes displayed coloration consistent with normal operation. The left and right magnetos had sustained impact energy damage, and were displaced from their respective mounting pad. The magnetos sustained varying degrees of damage that rendered the units inoperative and therefore, could not be functionally tested. The propeller hub was fragmented and the hub section remained attached to the crankshaft flange. Each of the recovered sections of propeller blade exhibited deformation and damage signatures consistent with the absorption of rotational energy at the time of impact with terrain. There was no evidence of pre-impact mechanical malfunctions observed during the examination of the engine or the airframe. ADDITIOINAL INFORMATION Regulations The FAA Aeronautical Information Manual (AIM) notes that hypoxia is a "state of oxygen deficiency in the body sufficient to impair functions of the brain," and "the e
The in-flight loss of control due to the pilot’s impairment as a result of hypoxia. Contributing to the accident was the pilot’s operation of the airplane above 12,500 feet without the aid of supplemental oxygen.
Source: NTSB Aviation Accident Database
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