Aviation Accident Summaries

Aviation Accident Summary WPR22FA021

Dunsmuir, CA, USA

Aircraft #1

N5268Q

CESSNA 150L

Analysis

The non-certificated pilot departed on a cross-country flight that required multiple fuel stops. The weather forecast called for clouds near the accident site. During the fuel stops, the pilot recharged the battery and, at one instance, refused assistance from witnesses to find and replace his alternator. Witnesses stated that he sparingly used the battery power for takeoff and landing and continued his cross-country flight with a known inoperable alternator. Postaccident examination of the cockpit revealed that the master switch was in the OFF position. With the master switch in the OFF position, the electrical system was not powered, and the airplane was not able to transmit its aircraft positions over its automatic dependent surveillance-broadcast (ADS-B) system. The field examination of the airplane wreckage did not reveal any mechanical malfunctions or failures that would have precluded normal operation. A witness near the top of the mountain reported that clouds and fog were present and provided a visibility of about 200 ft. He added that, about the time of the accident, he heard a low-flying airplane and was able to distinguish noise consistent with a running engine but did not hear the airplane’s impact with terrain. He further reported that the fog was present for most of the morning, lasting through the early afternoon. The pilot was likely flying the airplane low over the interstate to stay out of the clouds. He then likely entered instrument meteorological conditions as the airplane approached the mountain valley and turned back towards the departure airport before impacting trees in a wings-level attitude. No record was found indicating that the pilot received a preflight weather briefing; however, it could not be determined if the pilot obtained weather information using other sources. The pilot’s toxicology results indicate that he may have been experiencing impairing effects of diphenhydramine, such as sedation, at the time of the crash, and may also have been experiencing mild symptoms of uncontrolled diabetes, such as fatigue or blurry vision. However, the pilot’s decision to attempt the risky flight is unlikely to have been directly affected by these medical factors. Thus, given that the airplane was in controlled flight at the time of its collision with visually obscured terrain, there is low likelihood that the pilot’s diphenhydramine use or uncontrolled diabetes contributed to the crash.

Factual Information

On October 20, 2021, about 1100 Pacific daylight time, a Cessna 150L, N5268Q, was substantially damaged when it was involved in an accident near Dunsmuir, California. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. Multiple witnesses reported that the pilot was on a multi-leg cross-country flight that departed on October 19, 2021, from Sequim Valley Airport (W28), Sequim, Washington, about 1000 PDT, and was destined for Haigh Field Airport (O37), Orland, California. During a stop at Independence State Airport (7S5), Independence, Oregon, a witness reported the pilot charged the airplane battery, as he was having “issues” with the alternator. The witness offered the pilot assistance to find a replacement alternator, but the pilot refused. Witnesses reported that the pilot was “anxious” to get home and had a “get-there-itis" posture. After charging the battery at 7S5, the pilot departed for Ashland Municipal Airport-Sumner Parker Field (S03), Ashland, Oregon, and landed for an overnight rest stop. On October 20, the pilot departed S03 about 0940 PDT enroute to O37. The Federal Aviation Administration (FAA) issued an alert notification, or ALNOT, on October 20, at 1925 PDT, after a family friend became concerned as he had not heard back from the pilot, who was unreachable through the pilot’s cell phone. A search ensued and the airplane wreckage was subsequently discovered on a rising face of Mt. Bradley, about 725 ft below the summit, about 2 miles northwest of Interstate 5 near Dunsmuir, California. PILOT INFORMATION According to FAA records, the pilot had an expired student pilot certificate and reported civil flight experience that included 200 total hours and 0 hours in the six months before his last Aviation Medical Examiner examination on March 16, 1999. At that time, he reported no medication use or active medical conditions, and no significant issues were identified. A family member reported that he was a diabetic. Another witness added that the pilot has been flying as long as he has owned the airplane, which was about 20 years. METEOROLOGICAL INFORMATION There was no record of the pilot receiving a weather briefing or viewing weather imagery from Lockheed Martin Flight Service (LMFS), the Direct User Access Terminal Service (DUATS), or ForeFlight Mobile before departure. The pilot did not file a flight plan with ForeFlight Mobile. It is unknown whether the pilot retrieved weather graphics or text weather information from other internet sources. Weather Conditions at Time of Accident At 0840 PDT on the day of the accident, the weather at Rogue Valley International - Medford Airport (MFR), Medford, Oregon, elevation 1,335 ft, located about 15 nm from S03 (the last departure airport), included winds at 0 knots, visibility of 10 statute miles (sm), clouds broken at 6,500 ft, overcast at 8,500 ft, temperature and dewpoint at 9°/8°C respectively, and an altimeter setting of 29.96 inches of mercury. At 1050, the weather conditions recorded at Dunsmuir Municipal-Mott Airport (1O6), Dunsmuir, CA, elevation 3,261 ft, located about 3 nm northeast of the accident site, included winds from 100° at 4 knots, visibility 2 sm, light rain, clouds scattered at 700 ft, broken at 1600 ft, and overcast at 2,500 ft. The elevation of the accident site was about 5,314 ft. A power company lineman supervisor working near the Mt. Bradley lookout point on the day of the accident reported that a fog layer to the top of the mountain was present and allowed for a 200-ft visibility. Between 1100 to 1200, he heard a low-level airplane flying; he added that the engine sounded as if it was running but clarified that he did not hear the airplane impact terrain. He further reported that the fog was present for most of the morning and throughout the early afternoon. WRECKAGE IMPACT INFORMATION Examination of the accident site revealed that the airplane impacted a mountain about 5,290 ft mean sea level (msl). The airplane came to rest on a 15° slope on a heading of 350° magnetic. The first identified point of contact (FIPC) was identified by two 40-foot-tall pine trees and several broken tree branches, consistent with level flight. A debris path was marked by subsequent tree strikes that began about 75 ft forward of the FIPC and was oriented on a heading of 360° magnetic. The left wing was separated and found 20 ft southeast of the main wreckage. All major structures necessary for flight were accounted for at the accident site. Figure 1. Left picture: Location of wreckage site in relation to Dunsmuir, California. Right picture: Main wreckage location in relation to first identified point of impact.   The main wreckage marked the end of the debris path and was located about 225 ft beyond the FIPC. The nose, engine compartment, and the main landing gear came to rest inverted left of the cabin. The fuselage and cabin came to rest upright. The windscreen and both cabin doors separated. The cabin roof remained attached to the upper aft section of the fuselage. The cockpit had a bench seat installed. The instrument panel remained mostly intact and had impact damage. The split rocker-type master switch was in the OFF position (the left half controls the alternator, and the right half controls the battery). All other instrument switches were also in the OFF position. The ignition was in the BOTH position. The fuel selector lever was in the ON position. ADS-B was installed but not broadcasting due to the battery switch being in the OFF position. Both wings separated from their respective attachment points. The right wing separated from its respective root attachment point and came to rest upright, with its forward section partially resting on top of the tailcone. The right wing displayed a large area of compression damage on the leading edge starting 3 ft to 5 ft from its wing root, consistent with a tree strike. Its flight control cables cut through the upper skin up to midspan and displayed broom-straw failure, consistent with tension overload. The right wing tip was separated. Fuel was observed inside the right tank. The right aileron and flap remained attached and had impact compression damage. Flight continuity was confirmed from the aileron and the flap to its respective bellcrank. The left wing displayed compression wrinkles across the span of the wing. Two large areas of compression damage were displayed on its leading edge: one near the outboard and the other near inboard section of the wing, spanning about 3 ft each. The left wing tip was separated. The upper section of the left lift strut remained attached to the left wing while its lower section was separated from the fuselage. Fuel was observed inside the left tank. The left aileron and flap remained attached and displayed impact compression damage. Flight continuity was confirmed from the aileron and the flap to its respective bellcrank; flight control cables cut through the upper skin up to midspan and displayed broom-straw failure, consistent with tension overload. The left horizontal stabilator remained attached except for its tip and remained mostly undamaged. The right stabilator remained attached but displayed leading edge compression damage. The vertical stabilizer remained attached to the tailcone but was displaced to the left; compression damage was displayed on the left side of the tailcone near at the base of the vertical stabilizer. The rudder remained attached with minimal impact damage. Its respective cables remained attached to the bellcrank with the bellcrank displaced from impact damage. The elevator remained attached to its respective bellcrank; elevator trim continuity was confirmed. Both elevator and elevator trim cables displayed damage consistent with overload. The engine was displaced to the left of the fuselage and was inverted. The engine remained attached to the fuselage. All four cylinders remained attached. Each bottom spark plug was removed, and each spark plug was oily, with black deposits of carbon; each electrode was intact. Examination of the lower section of each cylinder revealed that each piston, wall, and upper spark plug remained intact. Each piston displayed carbon buildup and each upper spark plug had its electrodes intact with carbon buildup. The position of the engine did not allow the inspection of the upper section of the engine. The exhaust remained attached and secured. The oil sump remained attached and was removed; it was intact and had oil inside. The carburetor and its hoses, mixture lever, and throttle lever were secured and remained intact. After its removal, no anomalies were discovered. The vacuum pump remained attached and was removed; its coupling was attached and intact in one piece. The fuel filter bowl was examined; fuel was present inside the bowl with the filter screen free of debris. Both left and right magneto remained attached and secured along with their corresponding sparkplug wires. Each was removed and both couplings were attached and engaged when the gear was rotated. The battery remained attached with its connectors secured. The alternator remained attached and secured; it was removed, and the fan rotated freely and its wires remained attached and secured. The voltage regulator remained attached to the firewall with its connector and wires secured. According to the manufacturer’s owner manual, the alternator functioned to provide electrical power to the airplane and charge the battery. The 12-volt battery can also supply power to the aircraft; however, the manufacturer recommends that lone battery usage should be limited to checking the airplane’s electrical equipment during preflight. If the alternator switch is in the off position, the entire electrical load is placed on the battery. In an instance where the alternator does not function, the ammeter would indicate the discharge rate of the battery. Examination of the alternator revealed that there was no electrical continuity. The two McCauley blades were attached to the engine at the propeller hub with both blades bent aft about midspan. The crankshaft was slightly displaced to the left from impact damage. One blade displayed some chordwise scratches. The other blade was underneath the engine and could not be inspected. The examination did not reveal any evidence of mechanical malfunction or failures that would have precluded normal operation. MEDICAL AND PATHOLOGICAL INFORMATION The pilot’s autopsy was performed by a pathologist contracted by the County of Siskiyou Office of the Sheriff/Coroner, Yreka, California. According to the pilot’s autopsy report and a supplemental report from the Office of the Sheriff/Coroner, the pilot’s cause of death was exsanguination, and his manner of death was accidental. The Federal Aviation Administration's Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma, performed toxicological tests on specimens recovered from the pilot. The pilot’s postmortem toxicological testing detected the potentially sedating antihistamine medication diphenhydramine in urine and at 174 ng/mL in heart blood. The over-the-counter stomach acid suppression medication famotidine was detected in heart blood and urine; famotidine is not generally considered impairing. Hemoglobin A1c (HbA1c) was elevated at 8.6%. Glucose was measured at 5 mg/dL in vitreous and 1051 mg/dL in urine. Diphenhydramine, marketed under the trade name Benadryl, is an antihistamine used to treat allergies. Famotidine, marketed under the trade name Pepcid, is used to prevent, and treat heartburn due to acid indigestion, usually caused by eating or drinking certain foods. Witnesses reported that the pilot self-medicated with diphenhydramine and famotidine to alleviate an upset stomach.

Probable Cause and Findings

The non-certificated pilot’s improper decision to continue the flight under visual flight rules into instrument meteorological conditions which resulted in controlled flight into terrain.

 

Source: NTSB Aviation Accident Database

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