Loss of control in flight: Zenith Zodiac CH601 HDS, N6271F, fatal accident occurred on April 30, 2024, near Bristol, Indiana

• Location: Bristol, Indiana
• Accident Number: CEN24FA170 
• Date & Time: April 30, 2024, 14:18 Local 
• Registration: N6271F 
• Aircraft: Zenith CH601 
• Aircraft Damage: Substantial 
• Defining Event: Loss of control in flight 
• Injuries: 2 Fatal 
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194178/pdf

https://data.ntsb.gov/Docket?ProjectID=194178

On April 30, 2024, at 1418 eastern daylight time, a Zodiac CH-601 HDS airplane, N6271F, was destroyed when it was involved in an accident near Bristol, Indiana. The private pilot and pilotrated passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The private pilot and pilot-rated passenger were returning to their home airport following a personal flight. About 7 miles from the destination airport, the airplane’s airspeed increased, and it entered a steep descent. Witnesses reported that the airplane descended rapidly and impacted a wooded area. Witnesses also reported conflicting observations regarding whether the engine was operating normally. The engine examination did not reveal any preimpact anomalies, and the shattered and widely dispersed wooden propeller blade fragments were consistent with engine power at impact. The airframe examination did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation.

Toxicological testing of the pilot identified ethanol at low levels in several of the specimens and was not detected in brain tissue. Based on these results, some or all of the small amount of detected ethanol may have been from postmortem production rather than alcohol consumption, and it is unlikely that ethanol effects contributed to the accident. 

As a result of his heart disease, the pilot was at some increased risk of a sudden impairing or incapacitating cardiac event, such as chest pain, arrhythmia, or heart attack. The autopsy identified no evidence of such an event. However, an acute cardiac event occurring immediately before death may leave no reliable autopsy evidence. Whether the pilot’s heart disease contributed to the accident could not be determined.

Toxicological testing of the pilot-rated passenger identified two oral medications commonly used to treat diabetes. People with medication-treated diabetes are at risk for both abnormally high blood sugar (from diabetes) and abnormally low blood sugar (from medication effects). Short-term effects of high blood sugar may include decreased cognitive performance, including slower information processing speed, decreased executive function and attention.

Low blood glucose may cause difficulty concentrating, impaired task performance, and, in extreme cases, diminished consciousness, seizure, and death. The pilot-rated passenger’s postmortem urine glucose concentration is inconsistent with a markedly high antemortem blood glucose; however, it provides no information about whether his blood sugar may have been low. It also is unknown if the pilot-rated passenger had less severe symptoms of diabetes, such as fatigue or blurred vision or chronic complications associated with diabetes, such as vision loss, neuropathy, or kidney disease

As a result of his heart disease, the pilot-rated passenger was at some increased risk of a sudden impairing or incapacitating cardiac event, such as chest pain, arrhythmia, or heart attack. The autopsy identified no evidence of such an event. However, such an event does not leave reliable autopsy evidence if it occurs immediately before death. It is unknown what role the pilot-rated passenger had, if any, in aircraft operations and flight safety. Whether the effects of the pilot-rated passenger’s use of metformin and glipizide or his heart disease contributed to the accident cannot be determined.

Although either occupant could have experienced a sudden incapacitating medical event while manipulating the flight controls during the descent, the remaining occupant may have had insufficient time or opportunity to recover the airplane before impact. However, the investigation could not determine which occupant, if either, was manipulating the flight controls at the time of the accident. Therefore, whether either occupant experienced an incapacitating medical event that contributed to the accident could not be determined. 

- Probable Cause: The pilot’s loss of control during the descent for reasons that could not be determined, which resulted in a steep descent into terrain.

Aerodynamic stall/spin: Boeing-Stearman A75L3 (PT-17) Kaydet, N53466, fatal accident occurred on September 6, 2024, near Yacolt, Washington

• Location: Yacolt, Washington 
• Accident Number: WPR24FA298 
• Date & Time: September 6, 2024, 12:59 Local 
• Registration: N53466 
• Aircraft: Boeing A75L3 
• Aircraft Damage: Substantial 
• Defining Event: Aerodynamic stall/spin 
• Injuries: 1 Fatal, 1 Serious 
• Flight Conducted Under: Part 91: General aviation - Personal 

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/195073/pdf

https://data.ntsb.gov/Docket?ProjectID=195073

On September 6, 2024, about 1259 Pacific daylight time, a Boeing A75L3 airplane, N53466, was substantially damaged when it was involved in an accident near Yacolt, Washington. The pilot was seriously injured and the passenger was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The accident airplane was one of three airplanes traveling together on a cross-country flight. The pilots of the accident airplane and one of the other two airplanes chose to divert from the group’s typical route of flight to fly an alternate route through rising, mountainous terrain.

As the two airplanes approached an area of higher terrain and a ridgeline that required a climb, the pilot of the second airplane flying the alternate route initiated a circling climb to gain sufficient altitude needed to cross the approaching ridgeline. He then continued on toward the intended destination, unaware that the accident airplane was not behind his airplane.

When approaching the same ridgeline, the pilot of the accident airplane maintained an altitude that was lower than the elevation of the ridgeline and did not initiate a climb. The airplane maintained an altitude of about 2,900 ft mean sea level (msl) until it entered a left turn, followed by a rapid descent above the accident location. The airplane’s ground speed had slowed to 40 kts at the onset of the rapid descent and the left turn began about .63 statute miles from terrain that rose to 3,550 ft msl, which was the lowest available terrain ahead of the airplane’s position. The pilot likely initiated a left turn away from rising terrain and exceeded the airplane’s critical angle of attack. The investigation was unable to determine why the pilot did not initiate a climb earlier in the flight. 

The pilot of the second airplane flying the alternate route reported that “it wasn’t too smooth out,” which was consistent with terrain-induced wind and/or turbulence. He reported that at the initiation of his climb he added engine power, saw his ground speed decrease and then added additional engine power. He subsequently chose to circle climb to clear the ridgeline. The calculated density altitude near the accident site was 4,626 ft. 

Postaccident examination of the engine and airframe revealed no evidence of preaccident malfunction or failure.

- Probable Cause: The pilot’s exceedance of the airplane’s critical angle of attack while maneuvering at a low altitude in mountainous terrain in moderately high density altitude conditions, resulting in an aerodynamic stall and subsequent impact with terrain.

Unknown or undetermined: Grumman G-164A Ag-Cat, N9709, fatal accident occurred on June 25, 2024, near Chamberino, New Mexico

 

• Location: Chamberino, New Mexico
• Accident Number: WPR24FA213 
• Date & Time: June 25, 2024, 13:15 Local 
• Registration: N9709 
• Aircraft: GRUMMAN ACFT ENG CORSCHWEIZER G-164A 
• Aircraft Damage: Destroyed 
• Defining Event: Unknown or undetermined 
• Injuries: 1 Fatal 
• Flight Conducted Under: Part 91: General aviation - Instructional

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194549/pdf

https://data.ntsb.gov/Docket?ProjectID=194549

On June 25, 2024, about 1315 mountain daylight time, a Grumman Aircraft Engineering Corporation-Schweizer G-164A, N9709, was destroyed when it was involved in an accident near Chamberino, New Mexico. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 business flight.

Before the accident pilot departed on his first solo flight in the single-seat, turbopropellerequipped biplane, the chief pilot instructed him to depart to the north, climb to altitude, practice turns, climbs and descents, and then return to the departure airport. The chief pilot and the accident pilot were unable to communicate via radio and instead exchanged several text messages during the flight. The accident pilot sent a message stating, “it shakes a little bit, I don’t know if its normal,” to which the chief pilot replied, “Yeah it’s just a lot of horsepower on the front of the plane.” There were no further communications from the accident pilot. Shortly thereafter, the chief pilot observed smoke rising from the area where the pilot was operating. He departed in another airplane and subsequently located the accident site. 

Two witnesses saw the airplane flying low from north to south. Both witnesses reported that the engine sounded normal. One witness stated that he saw the airplane’s wings rocking left and right several times.

The airplane came to rest in sandy desert terrain and was largely consumed by a postimpact fire. No ground scars were observed near the accident site. All major components of the airplane were present, and impact damage was consistent with a right-wing-low, nose-down pitch attitude at the time of impact. Control continuity was established for the left and right lower wing flaperons from the cockpit to the control surfaces. Rudder control continuity was established from the cockpit to the rudder. Elevator control continuity could not be confirmed due to impact and thermal damage. Postaccident examination of the propeller revealed operational signatures consistent with low-to-moderate engine power. Postaccident examination of the engine revealed evidence consistent with the engine producing power at the time of impact, with no indications of preimpact mechanical malfunctions or failures that would have precluded normal operation. 

Review of the airplane’s maintenance records indicated that its most recent annual inspection was 13 months before the accident. The airplane was issued a special flight permit 20 days before the accident that was valid for 10 days and allowed the airplane to be ferried for repairs or maintenance. The chief pilot reported that the accident flight was the airplane’s first flight following maintenance and that the mechanic had not completed a logbook entry. The mechanic who performed the maintenance stated that she had started the airplane’s annual inspection but did not complete it, because the owner wanted to fly the airplane. When asked, the chief pilot stated that he made the decision to fly the airplane. Review of records provided by the operator after the accident revealed a new entry for an annual inspection, dated the day of the accident. 

Review of the pilot’s logbook indicated that, in the months before the accident, he received agricultural application training in several models of tailwheel-equipped airplanes, including a high performance, piston-engine-powered biplane; however, other than referring to “chair flights” performed before the accident flight, the operator did not provide additional information regarding the pilot’s transition training for the turbine-powered accident airplane. 

The orientation of the airplane at the accident site and the lack of ground scarring around the wreckage was consistent with the nose-low, near-vertical descent characteristic of an aerodynamic stall; however, the reason for the loss of control could not be determined based on the available information. Although examination of the wreckage did not reveal any mechanical malfunctions or anomalies, the scope of the examination was limited due to the thermal damage sustained during the postcrash fire. Given the pilot’s unfamiliarity with the accident airplane, it is possible that attempting to communicate with the chief pilot via text message during the flight provided an additional distraction that may have contributed to the loss of control.

- Probable Cause: An aerodynamic stall and loss of control for reasons that could not be determined based on the available information.

Unknown or undetermined: Erco 415-C Ercoupe, N3093H, fatal accident occurred on August 7, 2024, near Elkhart, Illinois

• Location: Elkhart, Illinois
• Accident Number: CEN24FA312
• Date & Time: August 7, 2024, 08:00 Local
• Registration: N3093H
• Aircraft: ENGINEERING & RESEARCH ERCOUPE 415-C
• Aircraft Damage: Destroyed
• Defining Event: Unknown or undetermined
• Injuries: 1 Fatal
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194886/pdf

https://data.ntsb.gov/Docket?ProjectID=194886

On August 7, 2024, about 0800 central daylight time, an Ercoupe 415-C airplane, N3093H, was destroyed when it was involved in an accident near Elkhart, Illinois. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight

The pilot was on a multi-leg cross country flight after purchasing the airplane. A friend of the pilot stated that the pilot landed the airplane at an airport on the first evening of the flight and was planning to continue west the next morning. A fuel receipt confirmed that the pilot purchased 16.34 gallons of fuel at that airport.

Two days after the flight was supposed to arrive at the final destination, the friend reported the pilot missing. The airplane was not equipped with ADS-B, and it did not have a transponder, so flight track data was not available for the investigation. On the evening that the pilot was reported missing, the airplane wreckage was found in a soybean field about 87 nm west of the last known fuel stop.

The main wreckage exhibited heavy thermal damage to the engine compartment, cockpit, and fuselage. The investigation was unable to determine if the fire started before or after impact. Examination of the airframe indicated that there were no preimpact mechanical malfunctions or failures that would have precluded normal operation.

The signatures on the propeller blades indicated that the propeller was likely not rotating at the time of impact and the engine was likely not producing power. Due to thermal damage, rust, and corrosion, the engine and magnetos could not be functionally tested. The investigation was unable to determine whether the engine lost power or if the pilot shut down the engine before impact with the ground.

The header tank and left and right fuel tanks were burned and compromised, during the accident sequence, so the fuel amount at the time of the accident could not be verified. However, based upon the fuel receipts, the pilot likely filled the airplane to its full 24-gallon capacity before departing.

The airplane’s emergency locator transmitter (ELT) was not transmitting on emergency frequency 121.5 MHz at the time the airplane was located, nor was there evidence of an ELT transmitting in the area in the days before the airplane was located. The airplane was found about an hour after search and rescue was deployed and three days after the accident likely occurred.

The pilot was found 18 ft away from the main wreckage and there was a 2 ft wide by 18 ft long trail of vegetation displacement between the main wreckage and his location. The vegetation displacement indicated the pilot was likely alive after the accident and either walked or crawled away from the wreckage and was not ejected upon impact.

According to the pilot’s autopsy report, his cause of death was thermal burns. His autopsy identified thermal burns over 80% of his body surface, without evidence of smoke inhalation or airway thermal injury. The autopsy report noted there was no fatal traumatic injury or lethal natural disease found. Based on available evidence, the possibility cannot be excluded that the pilot might have survived long enough after the crash to be transported to a burn center had rescue not been delayed. Regardless, his burns were very likely to be fatal even with specialized care. A widely used clinical burn mortality prediction tool predicts little to no hope of survival for a 77-year-old patient with 80% body surface area burns.

The pilot’s autopsy identified cardiovascular disease, including coronary artery disease and an old area of stroke. This cardiovascular disease was associated with increased risk of an impairing or incapacitating cardiovascular event. There was no autopsy evidence that such an event occurred, but such an event does not leave reliable autopsy evidence if it occurs immediately before death. The old stroke affecting a small area of the brain may or may not have had significant symptoms. The pilot had spine disease and a history of left leg weakness that had affected his ability to operate rudder pedals and foot brakes. His leg weakness would not be expected to directly affect control of an airplane without foot-operated controls, such as the accident airplane. However, chronic pain may have performance-impairing effects. Postmortem toxicology results indicated that the pilot had used the medication gabapentin, which the pilot’s daughter indicated the pilot was taking for back and leg pain. The pilot might have been experiencing associated impairing medication effects such as psychomotor or cognitive slowing at the time of the accident, but the magnitude of any such effects could not reliably be determined from the measured gabapentin level alone. 

Based upon ground scars and damage to the airplane, it is likely that the pilot attempted a forced landing to the field. The investigation was unable to determine why the pilot performed an off-airport landing in the soybean field. The airplane’s lack of ADS-B and transponder, and the failure of the ELT to activate as designed, delayed the rescue response. However, it is unlikely that the timing of the rescue response affected the survivability of the accident.

- Probable Cause: An off-airport landing in a soybean field for reasons that could not be determined. Contributing to the severity of the pilot’s injuries and airplane damage was a fire that occurred at an unknown time.

Aerodynamic stall/spin: Piper PA-18-150 Super Cub fatal accident occurred on May 14, 2024, near Thurlow, Montana

• Location: Thurlow, Montana
• Accident Number: WPR24FA150 
• Date & Time: May 14, 2024, 07:20 Local 
• Registration: UNREG 
• Aircraft: Piper PA-18-150 
• Aircraft Damage: Substantial 
• Defining Event: Aerodynamic stall/spin 
• Injuries: 2 Fatal 
• Flight Conducted Under: Part 91: General aviation - Other work use

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194259/pdf

https://data.ntsb.gov/Docket?ProjectID=194259

On May 14, 2024, about 0720 mountain daylight time, an unregistered Piper PA-18-150 airplane was substantially damaged when it was involved in an accident near Thurlow, Montana. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 other work use flight.

The pilot of the tandem seat, non-registered airplane and a passenger were conducting a predator control flight that targeted coyotes on private land. A wildlife control officer on the ground near the designated hunting area was communicating with the pilot via through cell phone and could hear gunfire when the call ended. The control officer attempted to call the pilot back after he expected the flight to have ended but did not determine a need to search for the airplane. A ranch hand located the wreckage later in the day. 

GPS data recovered from a handheld device found in the airplane wreckage showed that most of the flight was conducted at low altitudes. While engaging wildlife targets, the pilot slowed the airplane to as low as 36 kts groundspeed and performed multiple turns. During the last period of circling maneuvers the airplane slowed to about 25 kts groundspeed while about 113 ft above ground level (agl). The manufacturer’s Pilot’s Operating Handbook for a similar model of airplane indicated that the stall airspeed was 43 mph (37 kts).

Examination of the wreckage revealed the airplane impacted terrain in a nearly vertical, nosedown attitude while rotating clockwise. The wreckage signatures and very small debris area were consistent with an aerodynamic stall/spin. While maneuvering at low altitudes and low airspeed, the pilot likely exceeded the airplane’s critical angle of attack, which resulted in an aerodynamic stall/spin at an altitude too low for recovery. The pilot’s use of his cell phone, even with the aid of a hands-free device, likely distracted him from piloting duties.

The pilot’s toxicological testing revealed medications that had the potential to cause performance impairment and other medications that were commonly used to treat cold and allergy symptoms; however, toxicological testing did not establish that the pilot was impaired by the medication, nor that he was experiencing cold or allergy symptoms at the time of the accident.

- Probable Cause: The pilot’s exceedance of the airplane’s critical angle of attack while maneuvering at low altitude, resulting in an aerodynamic stall and subsequent impact with terrain. Contributing to the accident was the pilot’s distraction by his cell phone use while maneuvering.