Aviation Accident Summaries

Aviation Accident Summary WPR11FA147

Milford, UT, USA

Aircraft #1

N989TT

Neefjes Lancair 360 MK-II

Analysis

The pilot, who was not instrument rated, intended to fly to his destination while remaining in visual meteorological conditions (VMC). While en route, he entered an area where the clouds started to close in on him. Although the air traffic controller whom he was communicating with advised the pilot that there was an airport with VMC a short distance behind him, the pilot elected to attempt to proceed to his destination. As he continued, weather conditions became such that the pilot elected to land at an alternate airport. While being vectored to the alternate airport, the airplane's engine began to run rough, which, according to recorded engine analyzer data, was due to a restriction of the fuel flow in the orifice of the no. 1 cylinder injector nozzle. While attempting to deal with the rough running engine and maneuvering toward the alternate airport, the pilot inadvertently entered the clouds, and most likely lost control of the airplane due to spatial disorientation. The airplane then descended near vertically into the terrain. There was no record of the pilot receiving a weather briefing either from an FAA-contracted Flight Service Station or from either Direct User Access Terminal Service (DUATS) provider.

Factual Information

HISTORY OF FLIGHT On February 26, 2011, about 1730 mountain standard time, an experimental Neefjes Lancair 360 MK-II, N989TT, impacted the terrain about 6.5 five miles northwest of Milford, Utah. The private pilot, who was the sole occupant, received fatal injuries, and the airplane, which was owned and operated by the pilot, sustained substantial damage. The 14 Code of Federal Regulations Part 91 personal cross-country flight, which departed Grand Junction, Colorado, about 1 hour and 40 minutes prior to the accident, was en route to Chandler, Arizona. The airplane was initially being operated in visual meteorological condition (VMC), but as the pilot continued en route he entered an area where instrument meteorological conditions (IMC) prevailed. The pilot did not file a flight plan prior to departure, but he did contact the Air Route Traffic Control Center (ARTCC) while en route for assistance in reaching his destination while operating under visual flight rules (VFR). After departing Grand Junction, the pilot contacted Denver ARTCC for VFR flight advisories and routing assistance. As he approached the boundary of Denver Center's airspace, the pilot advised the controller that he may need to divert from his planned route due to weather, and might head more to the west toward Cedar City, Utah. The controller therefore gave the pilot the current Cedar City weather, and soon thereafter, about 1600, handed him off to Salt Lake Center. Approximately two and one-half minutes after he contacted Salt lake Center, the pilot told the controller that he was trying to divert through a cloud cover, and that the clouds were starting to close in on him. He then asked for the weather for Carbon County Airport, which was north of his planned route. The Carbon County weather the controller gave the pilot included the fact that it had a 3,300 foot overcast ceiling and a visibility of 10 miles. The controller further advised the pilot that the best weather in his vicinity was at Canyonlands Airport (Moab, Utah), which had a 6,500 foot broken ceiling; and that everything else in the area had broken ceilings below 3,000 feet. The controller then told the pilot that the weather at Page, Arizona, looked really good, with no ceiling, but with winds at 17 knots gusting to 26 knots. At that point the controller also explained to the pilot that since his weather radar was very inaccurate that he did not know how to route him to Page. Then about five minutes later, the controller advised the pilot that he had checked the weather at Vernal, Utah, which was about 50 miles behind the pilot, and that the weather report there indicated clear skies. The controller then checked with the crew of another airplane that was about 100 miles in front of the Lancair pilot, in order to get a report on the tops of the cloud layer in that location. That crew reported that the tops in that location were about 15,000 feet, and the controller passed that information on to the pilot. As the pilot continued to the west, he advised the controller that it appeared that the cloud tops might be higher than the reported 15,000 feet. The controller therefore asked the aforementioned crew for an update on the cloud tops in their present location, which was about 20 miles north of the Lancair, and the report came back that they were around 17,000 feet. The controller passed that information on to the pilot, and then, in response to another question from the pilot, confirmed that previous reports indicated that the tops started to go down "a bit" toward the west. About 11 minutes later, the pilot advised the controller that he was going to try to divert to Torrance, California (his home base), and asked if the controller had any weather information between his present position and Torrance. About 2 minutes later, the controller advised the pilot that he had looked at the Tonopah, Nevada and Las Vegas, Nevada weather, and that Las Vegas had an 8,500 foot broken ceiling, with an overcast ceiling at 14,000 feet, and that Tonopah had a 5,500 foot broken ceiling, with no overcast above. The controller further advised the pilot that he did not show any precipitation in the Las Vegas and Tonopah areas, and that in the Los Angeles area (near Torrance) there was no ceiling, but only scattered clouds at 6,000 feet and 20,000 feet, with winds at 18 knots gusting to 25 knots. The pilot responded to that information by stating, "I think I will head in that direction." About 5 minutes later the pilot was switched to the next Salt Lake Center sector controller, and about 6 minutes after that, after an inquiry from the controller, the pilot confirmed that he was "currently" at 13,600 feet. About 3 minutes later the pilot asked for an update on the cloud tops in his area and in the Las Vegas area. The controller therefore checked in with two other airplanes operating in the area, and determined that the cloud tops near Milford, Utah, were between flight level 250 and flight level 270, and that in the area of Saint George, Utah, the tops were about flight level 195, with light to moderate turbulence in the area. The controller passed this information on to the pilot, along with the updated weather for Las Vegas, which indicated an 8,000 foot broken ceiling, a visibility of 10 miles, and winds of 19 knots gusting to 23 knots. The pilot then asked if there was any precipitation between his position and Las Vegas, and the controller informed him that there was one area of precipitation, but that on his present course he would not enter that area. Then about 18 minutes after the pilot had been handed off to the sector controller, the controller asked him if he was still planning on going to Torrance, or if he was changing his destination to Las Vegas. The pilot responded that he was changing his destination to Las Vegas. About one minute after advising the controller that he was changing his destination to Las Vegas (about 1718), the pilot reported that he was "losing" his engine, and was declaring an emergency. The controller responded by asking him his intentions, and the pilot stated that he would like to divert to the nearest airport. The controller advised him that Milford was 15 miles to his east, and that Cedar City was a little bit further away and to the south. The pilot chose Milford, and after receiving a vector heading from the controller, he asked for the Milford weather. The controller informed the pilot that Milford's weather included heavy snow, freezing fog, and a visibility of ¼ mile. The pilot therefore asked for the Cedar City weather, which included light snow, mist, a visibility of 1/2 mile, few clouds at 600 feet, a broken ceiling at 2,900 feet, an overcast layer at 4,200 feet, a temperature of 1 degree C, and a dew point of 0 degrees C. The pilot then advised the controller that his engine was running very rough, but that he was not losing altitude. The controller acknowledged that transmission, and then about 45 seconds later informed the pilot that Saint George was reporting a broken ceiling at 3,600 feet, with an overcast layer at 4,200 feet, with a visibility of 10 miles. The pilot responded by asking the controller to vector him there, and the controller gave the pilot a heading vector and provided him with the airport identifier (DXZ). About 2 minutes later the controller directed the pilot to contact the next sector controller on the frequency he provided. About 15 seconds after giving the frequency change instructions, the controller noticed that the airplane was heading north (away from Saint George). Assuming that the pilot might still be on his frequency, the controller asked the pilot if he was just heading north for cloud avoidance. The pilot did not immediately respond, but about 15 seconds later transmitted that he was losing control of the airplane. The controller then advised the pilot that Milford was at 077 degrees from his position at 5 miles, and then asked the pilot if he was encountering any icing. The pilot responded with, "Negative so far," and about 20 seconds later stated that he had the airplane "stabilized a little bit." The pilot then asked where Saint George was from his present position, and the controller gave him a new heading for Saint George; but the pilot did not respond. The controller waited for about 30 seconds, and then asked the pilot if he was in the clouds right then, or if he was still in visual meteorological conditions. The pilot immediately responded with, "Right now I'm in the (unintelligent word)." That transmission, which took place at 1728:10, was the last radio contact with the pilot, and in just under 1 minute radar contact with the airplane was lost. The airplane was ultimately located in a ravine near where it was lost from radar, about 6 ½ miles west-northwest of Milford. The airplane was recovered to the facilities of Air Transport in Phoenix, Arizona, where it underwent a further examination and teardown inspection. PESONNELL INFORMATION The pilot was a 49 year old male who held a private pilot's license with an airplane single engine land rating. He did not hold an instrument rating. His last FAA airman's medical, a third class, was completed on September 24, 2009. He had one medical limitation, which was the requirement that he wear corrective lenses. According to the information in his pilot's logbook, he had accumulated about 520 hours of total flying time, of which about 70 hours were in a Lancair. AIRCRAFT INFORMATION The airplane was a single engine experimental Neefjes Lancair 360 MK-II, with a fuel injected Penn Yan Aero XE-360 180 horsepower engine and a Hartzell HC-F2YR-1F constant speed propeller. At the time of the accident, the airframe and engine had both accumulated about 185 hours since new. The airplane was built in Canada in 2006, and registered there as C-FHUB. It was imported into the United States in July of 2010, at which time it had accumulated about 118 hours since new. METEOROLOGICAL INFORMATION The 1706 aviation weather surface observation (METAR) for Milford indicated winds from 350 degrees at 12 knots, ¼ mile visibility, heavy snow, freezing fog, a vertical visibility of 400 feet into the obscuration (fog), a temperature of minus 3 degrees C, and a dew point of minus 4 degrees C. The Milford 1752 METAR indicated winds from 360 degrees at 14 knots, ¼ mile visibility, heavy snow, freezing fog, a vertical visibility into the obscuration of 200 feet, a temperature of minus 3 degrees C, and a dew point of minus 4 degrees C. A review of visible satellite imagery revealed that there were broken to overcast cloud layers over all of southwestern Utah, northwestern Arizona, and southeastern Nevada. The same imagery revealed that the tops of the clouds were uneven and were arranged in a gravity wave pattern indicative of turbulence. A review of the weather radar images and the infrared satellite images in the area of the accident revealed that clouds were present from the surface with tops variable to about 20,000 feet. There was no record of the pilot receiving a weather briefing from either an FAA-contracted Flight Service Station or from either Direct User Access Terminal Service (DUATS) provider. WRECKAGE AND IMPACT INFORMATION The airplane impacted flat open terrain that was sparsely covered by low brushy vegetation. It came to rest upright at 38 degrees, 26 minutes 22.8 seconds north; 113 degrees, 07 minutes, 7.68 seconds west. Although the fuselage structure had separated from the aft edge of the wing structure, and the empennage structure had separated from the aft end of the fuselage structure, the entire airframe was still connected by flight control tubes and/or electrical wires, and both fractured sections were lying within a few inches of where they had been attached. There were no ground scars beyond those directly below the airplane's structure, and there was no evidence that the airplane had made any horizontal movement once it contacted the terrain. The wings, fuselage, and empennage retained their original structural form, with the cockpit area, instrument panel, and engine compartment showing near vertical crushing damage. Flight control continuity was able to be established from the cockpit area to all flight controls. The engine, which underwent an NTSB-directed inspection at the facilities of Air Transport, contained fuel throughout its Precision Airmotive fuel injection system. There were no negative fuel system findings, and testing of the fuel with Kolor Kut water disclosing paste resulted in negative findings. The right magneto, which powered all the lower sparkplugs, was removed and produced spark when rotated by hand. The left magneto had been replaced by a LAS Plasma II CD ignition system, which powered all the bottom sparkplugs. That system was removed from the engine and underwent further testing described elsewhere in this report. The spark plugs (Denso W27EMR-C on the top, and Champion REM-40E on the bottom) were inspected for signs of excessive wear, arching, particulate contamination, and cracked insulators. The findings were negative. The oil system appeared to be intact, and an unmeasured amount of oil was observed in the sump. The vacuum pump was removed and disassembled. Its rotor was fractured, but there were no pre-impact negative findings. The engine was rotated by hand using the propeller, and all cylinders produced suction and compression when their respective sparkplug holes were covered with a thumb. All rocker arms, valves, and the accessory drive gear were observed to move when the propeller was rotated by hand. All cylinders were examined with a lighted borescope, and no defects were found. The exhaust system was examined, and it was noted that the color of the number 1 cylinder exhaust runner was lighter than the other three, which is consistent with a leaner air fuel mixture burning in that cylinder. During the course of the engine examination, nothing was observed that indicated the existence of an anomaly that would have precluded the engine from making power prior to the initiation of the accident sequence. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy completed by the office of the Utah State Medical Examiner determined that the pilot's manner of death was accidental, and his cause of death was determined to be blunt force injuries sustained during an airplane crash. The FAA's Civil Aerospace Medical Institute (CAMI) performed a forensic toxicology examination on specimens recovered from the pilot, and the results were negative for all tests performed. TESTS AND RESEARCH The control unit, ignition coils, sparkplugs, and crankshaft sensor from the LSE Plasma II CD ignition system were removed from the airplane and inspected/tested under direct NTSB oversight at the facilities of Light Speed Engineering of Santa Paula, California. All components were tested at varying speed ranges from 200 to 3,000 rpm, with a consistent and even spark being produced at all the spark plug electrodes. The throttle body, flow divider, and fuel injection nozzles from the Precision Airmotive EX-5VA1 fuel injection system were removed from the airplane and inspected/tested under direct NTSB oversight at the facilities of Precision Airmotive Corporation of Marysville, Washington. The flow divider tested within production specifications at all test points. Injection nozzles 1, 3, and 4 flowed within the specified parameters of 31.4 to 32.6 pounds per hour, and all had good stream patterns. Injection nozzle 2, which had damaged threads and also slight damage to the insert flare, flowed at 31.2 pounds per hour, with a good stream pattern. The throttle body itself had sustained impact damage that left the mixture control seized near the full rich position, and kept the throttle lever from being moved below the ½ open position. Although it was expected that it would flow overly rich during a flow test, which it did, upon disassembly no evidence of an anomaly or a malfunction was found that would have keep it from functioning properly at cruise flight. The Stern Technologies Pulsar 200 Engine Analyzer was removed from the airplane and shipped to the NTSB laboratory in Washington, D. C., where its recorded raw data for the flight was

Probable Cause and Findings

The pilot's loss of control of the airplane due to spatial disorientation after inadvertently entering instrument meteorological conditions. Contributing to the accident were the pilot's inadequate preflight preparation, his en route decision-making, and his distraction due to a partial loss of engine power due to a restriction in a fuel injection nozzle.

 

Source: NTSB Aviation Accident Database

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