WPR23FA257

The flight crew’s decision to descend below the decision altitude of an instrument approach without having the appropriate runway visual reference(s) distinctively identified and with the visibility below the minimum that was prescribed for the approach, which resulted in controlled flight into terrain.

During an early morning night flight, the flight encountered deteriorating weather conditions with a low overcast ceiling and rapidly decreasing visibility at the destination due to fog. A few minutes before the flight’s arrival time at the destination airport, the weather had changed from being clear with 10 statute miles (sm) visibility to 300 ft overcast with 3/4 sm visibility. Additionally, in the next 20 minutes, the visibility further decreased to about 1/2 sm with fog. The airplane was cleared for the RNAV (GPS) Runway 18 instrument approach to the airport. The lowest visibility requirement on the approach was 7/8 of a mile. During the final approach, the pilot executed a missed approach and asked to try another instrument approach. During the second instrument approach, while on final approach, the pilot failed to fly a stabilized approach as the airplane’s descent rate and airspeed were excessive. Subsequently, the airplane descended below the decision altitude of the approach without appropriate visual references and impacted terrain about 810 ft short of the runway threshold. The circumstances of the accident flight were consistent with controlled flight into terrain (CFIT). The postaccident examination of the airplane and engines revealed no evidence of mechanical failures or malfunctions that would have precluded normal operation of the airplane. The pilot had very low levels of ethanol detected in postmortem vitreous fluid and cavity blood. Some or all of this small amount of ethanol may have been from sources other than alcohol consumption. Although it is uncertain whether the pilot had consumed alcohol overnight, the toxicology results indicate that it is unlikely that the pilot’s performance would be significantly affected by ethanol. The copilot’s ethanol levels were high in all tested postmortem specimens. Based on the toxicology results and the circumstances of the event, it is likely that the copilot had consumed alcohol. However, based on the extent of his injuries, the presence of indicators of microbial decomposition, and the relative differences in ethanol levels across specimens, it also is likely that some of the detected ethanol was from sources other than alcohol consumption. The copilot’s blood alcohol level at the time of the crash cannot be reliably determined from available evidence. Overall, alcohol-related impairment may have limited the copilot’s ability to make a positive contribution to flight safety (such as by helping to monitor the approach); however, whether the effects of alcohol use by the copilot contributed to the accident outcome could not be determined.

A review of the NWS Surface Analysis Chart revealed that a low-pressure system was located at the intersection of the California, Nevada, and Arizona borders. A sounding analysis model indicated a cloud layer between 1,650 ft and 2,650 ft msl. No icing was indicated below 10,000 ft msl. No possibility of low-level wind shear (LLWS) was depicted. Light clear air turbulence was indicated in several layers between 1,000 ft and 10,000 ft. The F70 automated weather forecast at 03:15 Pacific daylight time called for clear ceilings and 10 sm of visibility. At 03:55, the ceiling and visibility rapidly decreased to overcast at 300 ft agl and 3/4 visibility with mist. At 0415, near the accident time, the ceiling remained overcast at 300 ft agl and the visibility decreased to 1/2 mile with fog. There were no disseminated pilot reports (PIREPS) distributed into the national airspace system during the two hours before and after the accident time within 100 miles and below an altitude of 18,000 ft. There were no convective or non-convective Significant Meteorological Information (SIGMET) advisories valid for the accident site during the accident time. The NWS Aviation Weather Center had Airmen’s Meteorological information (AIRMET) advisory Sierra valid for the accident site and time for below 8,000 ft. The AIRMET Sierra was issued at 0145 and updated at 0401 with forecast mountain obscuration conditions due to clouds and fog. The NWS weather forecast office in San Diego, California, issued the following area forecast for the region of the accident site: Areas of low clouds will gradually spread to 20 miles inland by 1200Z Sat with bases 1000-1600 ft msl, with local terrain obscurations. A search of archived information indicated that the accident pilot did not request weather information from Leidos Flight Service. The pilot did have an account through Foreflight and filed a flight plan, but no weather imagery was viewed in Foreflight. Astronomical data for the accident location and time indicated that sunrise was 0545 and moonrise was 0454. Both pilots had a type rating for the CE-550 aircraft with the limitation of a second pilot-in-command required. According to the airplane’s operating manual, the reference speed with flaps positioned to land, pressure altitude 2,000 ft, anti-ice systems off, 10°C, and at a gross weight of 9,500 pounds was 95 knots indicated airspeed (KIAS); at a gross weight of 10,000 pounds, the reference speed was was 99 KIAS. The Riverside County Sheriff’s Coroner Division performed an autopsy on the pilot’s remains. The autopsy report listed the cause of death as “blunt force trauma.” The FAA Forensic Sciences Laboratory performed toxicological testing on specimens from the pilot. The pilot’s results for the testing of drugs of abuse, alcohol, and carboxyhemoglobin were negative. Ethanol was not detected at a reporting threshold of 0.01 g/dL. The Riverside County Sheriff’s Coroner Division performed an autopsy on the copilot’s remains. The autopsy report listed the cause of death as “blunt force trauma.” The FAA Forensic Sciences Laboratory performed toxicological testing of postmortem specimens from the copilot. Ethanol was detected at 0.196 g/dL in chest cavity blood, at 0.109 g/hg in brain tissue, and at 0.365 g/hg in liver tissue. N-propanol, n-butanol, and methanol were also detected at low levels in blood but were not detected in brain or liver tissue. The toxicology report noted subjective evidence of organic decomposition. N-propanol and n-butanol are alcohols that can be produced by microbes in a person’s body tissues and fluids after death. Methanol is wood alcohol; it is present at low levels in some foods and drinks and has a variety of industrial uses. There is some evidence that methanol detected in a postmortem specimen may be more likely to be due to dietary sources (such as alcoholic beverage consumption) or contamination rather than postmortem microbial production, although postmortem methanol production has been reported. Ethanol is the intoxicating alcohol in beer, wine, and liquor, and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance, with detrimental effects on piloting tasks that worsen as ethanol levels increase. FAA regulation imposes strict limits on flying after consuming ethanol, including a prohibition on piloting a civil aircraft while having a blood ethanol level of 0.04 g/dL or greater. When absorbed into circulation after alcohol consumption, ethanol distributes relatively evenly throughout the body along with water. In living people, ethanol is eliminated from blood at a rate of approximately 0.008 to 0.035 g/dL per hour (0.01-0.025 g/dL per hour for most people). Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol sometimes may be produced by microbes in a person’s body tissues and fluids after death, potentially elevating ethanol levels in affected postmortem specimens. Postmortem ethanol production is made more likely by extensive trauma, which can spread microbes. Vitreous fluid typically is better protected against the spread of microbes and therefore is less susceptible to postmortem ethanol production than are other specimen types. However, postmortem ethanol production can occur in vitreous fluid. Examination of the accident site revealed that the airplane impacted terrain on the extended runaway centerline about 810 ft short of the runway 18 threshold at F70. The terrain was covered with sagebrush at an elevation of about 1,340 ft msl. All major components of the airplane necessary for flight were found at the accident site. The airplane’s configuration was determined to be gear down and flaps fully extended. Flight control continuity was established. A review of the enhanced ground proximity warning system (EGPWS) unit revealed that the accident flight data was present. A single Mode 4 too-low gear alert was the only alert recorded and was consistent with an alert after the airplane accomplished a missed approach on the first approach and retracted the landing gear at a low altitude. The postaccident examination of the airplane and engines revealed no evidence of mechanical failures or malfunctions that would have precluded normal operation of the airplane. On July 8, 2023, about 0414 Pacific daylight time, a Cessna 550, jet airplane, N819KR, was destroyed when it was involved in an accident near Murrieta, California. The 2 pilots and 4 passengers were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal flight. According to ADS-B and air traffic control data provided by the Federal Aviation Administration, the airplane departed French Valley Airport (F70), Murrieta/Temecula, California, on a cross-country flight to Harry Reid International Airport (LAS), Las Vegas, Nevada, about 2118 the night before. The airplane departed on the return flight back to F70 about 6 hours later. After climb-out, the airplane leveled off at an altitude of about 19,000 ft mean sea level (msl). About 27 minutes into the flight, the airplane started a descent to its destination. About 0344, the pilot established contact with the Pomona radar controller and requested to cancel their IFR clearance. The controller acknowledged the cancellation and provided the altimeter setting and advised that VFR altitude and routing was at their discretion and that he had no weather or landing information for F70. The pilot responded and advised that he had the weather and landing information for F70. About 0351, and about 25 miles north of F70, the pilot reported that he had received updated weather and requested an IFR pickup for the RNAV (GPS) Runway 18 approach at F70. A few minutes before their arrival time at the destination airport, the weather had changed from being clear with 10 sm visibility to 300 ft overcast with 3/4 sm visibility.