Aviation Accident Summaries

Aviation Accident Summary ERA20LA330

Floral City, FL, USA

Aircraft #1

N6106Z

Piper PA25

Analysis

The commercial pilot departed a nearby airport to conduct agriculture spraying. During the third spray pass from west to east a witness observed the airplane abruptly pull up and then descend rapidly into a tree line after which an explosion and postcrash fire occurred. About 350 ft directly west of the main wreckage, a large dead tree with vegetation growth was present in the field being sprayed. The tree contained broken branches and components of the agricultural spraying equipment near its base. The spray fan nose cone exhibited a large dent impact signature. It is likely that during the low spraying pass, the agricultural spraying equipment mounted on the bottom of the fuselage struck the dead tree. At some point prior to or after the collision, the pilot likely rapidly pulled up, but subsequently lost airplane control, and impacted a row of trees inverted. Examination of the airplane did not reveal any anomalies that would have precluded normal operation. Multiple factors likely contributed to the airplane’s collision with the tree. The first factor was that the pilot’s spraying approach from west to east was toward the shorter portion of the field, which forced the pilot into making shorter low passes and reduced his time to see and avoid the tree. He had previously sprayed the field about 4 weeks prior to the accident from the north to south, which would have allowed for longer spray runs due to the field being oriented longer on a north/south direction. Second, the sun had risen about 30 minutes prior to the accident and the sky was clear. It is likely that the eastward path presented the pilot with a combination of sun glare and shadows in the field due to the low sun angle and the row of trees that lined the eastern portion of the field. Lastly, the tree had significant vegetation growth that was similar to the color of the field being sprayed, which possibly camouflaged portions of the tree. These factors likely affected the pilot’s ability to see and avoid the tree. The pilot had autopsy findings of moderate coronary atherosclerosis in one artery and was taking high blood pressure medications. These cardiovascular conditions placed the pilot at some increased risk for an acute cardiac event, however, there was no operational or medical evidence to suggest that occurred. Thus, it is unlikely that the pilot’s cardiovascular disease was a factor in the accident. Toxicology results found that the pilot was taking medication for diabetes and likely had an elevated blood glucose on the day of the accident; however, there was no evidence to suggest that the pilot’s high blood glucose and diabetes contributed to the accident.   Toxicology testing also found evidence of the impairing drug cannabis. The levels found suggested that usage may have been some time earlier in the day. However, toxicology results alone cannot be used to prove that the user was experiencing effects of cannabis at the time of the accident. Metabolism and elimination depend on the means of ingestion, potency of the product, frequency of use, and user characteristics; information the medical investigation did not obtain. As a result, it could not be determined whether the pilot's use of a potentially impairing substance contributed to the accident.

Factual Information

On September 23, 2020, about 0750 eastern daylight time, a Piper PA-25 airplane, N6106Z, was destroyed when it was involved in accident near Floral City, Florida. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 137 aerial application flight. According to a flight instructor who was preparing for flight at the nearby Inverness Airport (INF), Inverness, Florida, he observed the accident pilot fill the airplane with chemicals and depart runway 19 shortly thereafter. The flight instructor subsequently departed and remained in the traffic pattern where he observed the pilot spraying fields south of INF. According to a solo student pilot also in the traffic pattern at INF, while turning right downwind for runway 01, he glanced down and saw that the accident airplane was “spraying” and it looked like “he pitched up to clear something and then abruptly went down.” The student pilot subsequently observed fire and smoke emanating from where he last saw the airplane. An additional witness was located on a tractor in a nearby farm field. He reported that he observed the accident airplane spraying from west to east and it had “dipped down two times, coming down near the trees and then coming back up.” He reported that at that time of day the sun would have been in the pilot’s eyes. He then observed the airplane on its third approach, and it was “real low” and he “never saw him [the airplane] come back up.” He subsequently observed black smoke and heard explosions. According to a Federal Aviation Administration (FAA) inspector who traveled to the accident site, the main wreckage was located inverted in a row of trees that lined the field the airplane was spraying. A postcrash fire consumed a majority of the fuselage; however, all primary flight controls were present with the main wreckage. He reported that within the field that was being sprayed, about 350 ft directly west of the main wreckage, a large dead tree with vegetation growth contained broken branches and components of the agricultural spraying equipment near its base. Figure 1 provides a view of the dead tree and the spraying equipment that was found about 25 ft east of the tree. An additional photo in the figure shows where the agriculture equipment was likely mounted on the accident airplane. Figure 1: View of the dead tree in the field being sprayed, with accompanied photographs of the agriculture spraying equipment located in the field. Figure 2 provides an overview of the field being sprayed, the accident site area, and the reported flight path direction. Figure 2: Overview of the accident site area. Flight control continuity was established for all flight control surfaces during examination of the engine and airframe at the recovery facility. The engine sustained significant fire damage; however, engine continuity was established for the crankshaft, camshaft, and pistons. The propeller blades were bent slightly aft and the tip of one blade showed “S” bending. The agriculture spraying fan displayed a large impact damage witness signature on its nose cone. The examination did not reveal any anomalies that would have precluded normal operation of the airplane. According to the pilot’s spouse, the pilot had sprayed the field about 4 weeks prior to the accident. She added that she was taking photographs when the pilot performed the previous spraying and that he utilized a north-south spray pattern. She further stated that spraying east-west would require “much shorter passes before turns.” The sunrise was 0718 the day of the accident and the wind was reported calm at nearby INF. The National Oceanic and Atmospheric Administration Solar Calculator showed that the azimuth of the sun about the time of the accident was 93.76° with an elevation of 6.21° above the horizon. The commercial pilot held a second-class medical certificate issued on April 13, 2020, with the limitation that he must wear corrective lenses for near and distant vision. At this most recent examination, he reported taking no medications and having resolved his previous diagnoses of diabetes and high blood pressure by diet and exercise. The pilot’s spouse reported that at the time of the accident, the pilot was taking medications for diabetes, high blood pressure, and gastric reflux. According to the autopsy report, the cause of death was multiple blunt force injuries due to an airplane collision and the manner of death was accident. The medical examiner reported that the pilot had 60% atherosclerosis in his left anterior descending coronary artery and moderate atherosclerosis of his aorta. Toxicology testing was performed at the FAA Forensic Sciences Laboratory and the medical examiner’s office. Toxicology testing identified the diabetes medication glipizide in the pilot’s blood and urine. Post-mortem clinical laboratory findings showed the pilot had vitreous fluid and urine glucose concentrations of 130 mg/dL and 1,264 mg/dL, respectively and a hemoglobin A1C of 6.3%. Toxicological testing also detected tetrahydrocannabinol (THC) in the pilot’s blood and urine (6.5 and 6.7 ng/mL, respectively) and THC’s psychoactive metabolite 11-hydroxy-delta-9-THC in blood and urine (1.2 and 77.9 ng/mL, respectively). THC’s inactive metabolite THC-COOH was detected in his blood (31 and 29.4 ng/mL) and urine (671.3 ng/mL). The cannabis plant contains chemicals called cannabinoids; tetrahydrocannabinol (THC) is the primary psychoactive cannabinoid compound. THC's mood-altering effects include euphoria and relaxation. In addition, marijuana causes alterations in motor behavior, time and space perception, and cognition. Significant performance impairments are usually observed for at least 1-2 hours following marijuana use, and residual effects have been reported up to 24 hours.

Probable Cause and Findings

The pilot’s failure to see and avoid a tree while flying towards the rising sun during an aerial application flight, which resulted in a collision with the tree and a subsequent loss of airplane control.

 

Source: NTSB Aviation Accident Database

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