CEN19FA008

The partial loss of engine power due to induction system icing. Contributing to the accident was the fractured carburetor heat control cable, which rendered the carburetor heat inoperative.

The pilot was conducting a cross-country flight when the airplane had a loss of engine power while descending through an area of precipitation and icing conditions. He was unable to restore normal engine operation using carburetor heat, which resulted in a forced landing. The airplane struck the terrain in a right wing down attitude and cartwheeled upon impact. Shortly after the accident, an individual observed several pieces of structural ice on the ground below the airplane’s left wing leading edge. After the accident, the engine demonstrated the ability to produce rated horsepower during an engine test. However, the carburetor heat control cable was found fractured and exhibited evidence of prolonged polishing wear against the cable sheathing. It is likely that the carburetor heat control cable had failed in overstress due to its reduced cross section from the polishing wear. Additionally, based on contaminants observed on the cable and fracture surfaces, the carburetor heat control cable had been fractured for an extended period before the flight. The airplane was not approved for flight in known icing conditions; however, if inadvertently flown in icing conditions, the carburetor heat should be engaged to avoid a loss of engine power due to induction air filter icing and/or carburetor icing. It is likely the loss of engine power during the flight was due to an accumulation of ice on the induction air filter and/or to the carburetor, and the pilot was unable to restore engine power because the fractured control cable had rendered the carburetor heat inoperative. According to the airplane’s operating handbook, pilots are to verify the proper operation of the carburetor heat during an engine runup before each flight. A review of the airplane’s flight track and weather data indicated the airplane had flown through areas of precipitation that were consistent with freezing drizzle and supercooled liquid water droplets favorable for structural icing conditions. There was no record that pilot had received a weather briefing before the flight and, as such, his awareness of the icing conditions before the flight could not be determined.

The National Weather Service (NWS) National Composite Radar Mosaic at 1620 depicted an area of light to moderate precipitation echoes surrounding the accident site with several west-to-east oriented bands located west and south of the accident site. There was no evidence of any organized strong convection or thunderstorms. Additionally, the NWS Aviation Weather Center (AWC) data indicated visual flight rules (VFR) conditions at the accident site with overcast ceilings between 3,700 and 5,500 ft agl, and that a large area of precipitation extended across western New Mexico and along the route of flight. An upper air sounding for the Albuquerque area detected a low-level temperature inversion at 3,054 ft agl, and a lifted condensation level (LCL) about 5,300 ft agl that was associated with the cloud base. The freezing level was at 9,900 ft msl and supported a mixture of rime and mixed icing through 16,000 ft msl where the relative humidity exceeded 75%. NWS weather radar base reflectivity images at 1607, 1614, and 1620 depicted a large area of light to moderate precipitation over the accident site and along the route of flight at altitudes between 13,000 ft msl and 19,000 ft msl. A review of the airplane’s flight track indicated the airplane had flown through precipitation echoes that were consistent with freezing drizzle and supercooled liquid water droplets favorable for structural icing conditions. The NWS AWC Current Icing Products (CIP) analysis for 1600 indicated there was greater than 65% probability of icing conditions between 11,000 and 17,000 ft msl across Arizona and into western New Mexico. There was a 35% probability of icing in the Albuquerque area at 16,500 ft msl, and the probability of icing increased to over 75% between 11,000 and 13,000 ft msl. The CIP Icing Severity indicated light to moderate icing and the possibility of supercooled large droplets (SLD). There were no Significant Meteorological Advisories (SIGMETs) or Center Weather Advisories issued at the time of the accident. The NWS had issued several Airmen’s Meteorological Information advisories (AIRMETs) for mountain obscuration over most of Arizona and New Mexico, moderate turbulence below 18,000 ft msl, and moderate icing conditions between the freezing level and 21,000 ft msl. A separate AIRMET for instrument flight rules (IFR) conditions was also current over central and eastern Arizona, which included an earlier portion of the flight. The NWS Winds and Temperatures Aloft Forecast current for the flight indicated a freezing level between 9,000 and 10,000 ft msl. About 30 minutes before the accident, several pilot reports (PIREPs) were filed for light to moderate rime icing conditions, and between 1552 and 2020 there were 9 PIREPs for trace to moderate rime icing conditions between 10,000 and 23,500 ft msl. A search of official weather briefing sources indicated that the pilot had not received a weather briefing before the flight. The autopsy reports for the pilot and passenger attributed their cause of death to multiple blunt-force injuries, and toxicology testing was negative for ethanol, carbon monoxide, and all tested drugs and medications. The airplane was powered by a 285-horsepower, 6-cylinder, Continental O-550-F/TS reciprocating engine, serial number 284691-R. The original fuel-injection system had been replaced with a carburetor when modified by Texas Skyways Supplemental Type Certificate No. SE09131SC. The engine had accumulated 201.23 hours since being installed on August 2, 2017. The airplane had accumulated 21.23 hours since the last annual inspection that was completed on October 4, 2018, at 11,179 total airframe hours. According to the Cessna 182P Pilot’s Operating Handbook (POH), the airplane was not approved for flight in known icing conditions. The POH indicates that carburetor heat should be used to avoid a loss of engine power due to air filter icing and/or carburetor icing while the airplane is operating in inadvertent icing conditions, and that “an unexplained loss in manifold pressure could be caused by carburetor ice or air intake filter ice.” According to the Before Takeoff checklist, pilots are to verify the proper function of the carburetor heat before each flight. Additionally, an accumulation of airframe ice on the leading edge of the wing ¼ inch or greater will result in a significantly higher stall speed. On October 16, 2018, about 1622 mountain daylight time, a Cessna 182P airplane, N9326G, was substantially damaged when it was involved in an accident near Canoncito, New Mexico. The pilot and his passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to recovered GPS track data, the cross-country flight departed earlier in the day from Fullerton Municipal Airport (FUL), Fullerton, California, and made a planned fuel stop at Lake Havasu City Airport (HII), Lake Havasu City, Arizona. The manager of the fixed base operator at HII reported that the airplane was fueled with 30.9 gallons of 100 low-lead aviation fuel before it departed. According to air traffic control (ATC) data and GPS track data, the flight departed HII about 1234 and climbed to an assigned cruise altitude of 19,000 ft mean sea level (msl) while continuing toward Albuquerque, New Mexico. At 1608:25, the pilot established contact with Albuquerque Approach and reported descending through 14,600 ft msl to 10,000 ft msl. The controller relayed the current weather conditions for Double Eagle II Airport (AEG), Albuquerque, New Mexico, told the pilot to fly direct to the Albuquerque Very High Frequency Omni-Directional Range (ABQ VOR), and to expect the visual approach to runway 14 at AEG. At 1612:19, the controller told the pilot that the airplane was on a southerly track, to turn to a 080° heading, and then resume a direct course to the ABQ VOR. At 1613:35, the controller asked the pilot to verify his heading. The pilot replied, "about seventy-two right now sir, we're going back to eighty in a minute." At 1613:43, the controller told the pilot to descend to maintain 9,000 ft msl. The pilot replied, "down to nine thousand, two six golf, yeah, we're just taking it real slow sir." At 1613:53, the controller told the pilot to advise if he was going to deviate from assigned headings. The pilot replied, "ah, you bet, thanks, we are just going around some clouds here." The controller then approved the pilot to make heading deviations to avoid clouds and to resume a direct course to the airport when able. At 1614:16, the pilot replied, "direct to the airport after deviations for two six golf, yeah, in fact, we are just getting into some a little bit of precipitation here." The controller cleared the pilot to deviate as necessary to avoid the precipitation and to begin the descent to maintain 9,000 ft msl. At 1616:05, as the airplane was descending through 10,000 ft msl, the pilot transmitted, "two six golf has got engine problems at this point." At 1616:14, the controller confirmed with the pilot that he was having engine issues. The pilot replied, "yes sir, um, can't really tell what's going on here." The controller replied, "ah, might be some icing, use caution there is high terrain below you, um, I-40, ah, Interstate 40 is located off your right wing and about nine, nine to ten miles." At 1616:38, the pilot replied, "yeah, we've broken out, we are under the clouds now, but, ah, yeah, I'm trying to get it to run here." The controller then told the pilot to make a right turn to a 120° heading to intercept Interstate 40. According to GPS track data, the airplane made a right turn to the east-southeast toward Interstate 40. At that point the airplane was at 9,000 ft msl, about 9.5 nautical miles (nm) west-northwest of Interstate 40, and about 16 nm west-southwest of AEG. At 1617:33, the pilot transmitted, "and I've got my power back with the carb heat