Structural icing: Gulfstream 695A Jetprop Commander 1000, N965BC, fatal accident occurred on April 13, 2024, near San Bernardino, California

• Location: San Bernardino, California 
• Accident Number: WPR24FA124 
• Date & Time: April 13, 2024, 20:19 Local 
• Registration: N965BC 
• Aircraft: Gulfstream Corporation 695A 
• Aircraft Damage: Destroyed 
• Defining Event: Structural icing 
• Injuries: 1 Fatal 
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194082/pdf

https://data.ntsb.gov/Docket?ProjectID=194082

On April 13, 2024, about 2019 Pacific daylight time, a Gulfstream Corporation 695A airplane, N965BC, was destroyed when it was involved in an accident near San Bernardino, California. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The accident pilot had been in a recurrency training program in the accident airplane the week before the accident flight, which was the return flight after completing the week with the instructor. According to the instructor, the pilot wanted to proceed home so they had planned for the accident pilot to depart on that leg of the flight no later than 1830 for a route of flight that remained west of specific terrain due to weather forecasts and that would arrive at the destination airport before dark. The pilot subsequently departed about 30 minutes past the planned departure time and flew a route east of the terrain that had been discussed, which placed the airplane in severe weather conditions after dark.

While descending from its cruising altitude, the airplane encountered turbulence and the autopilot disengaged. For the remainder of the flight, multiple transmissions were recorded between air traffic control (ATC) and the pilot regarding course corrections, altitudes, icing conditions, and issues with the airplane’s autopilot. ATC offered vectors from the arrival procedure; however, the accident pilot declined the vectors. After receiving another pilot’s report of airframe icing from ATC, the accident pilot confirmed to ATC that he had accumulated moderate rime ice and agreed when ATC offered a lower altitude. When ATC asked, the pilot confirmed that the airplane remained in icing conditions during the continued descent, and the airplane subsequently leveled at 7,200 ft above mean sea level (msl).

ATC instructed the pilot to climb the airplane to the last assigned altitude of 7,400 ft msl; however, the airplane remained at 7,200 ft msl for 29 seconds and began a right turn. During flight at 7,200 ft msl, the airplane’s groundspeed slowed from 124 kts to 84 kts. ATC asked the pilot if he was ready to turn back to the left and the pilot responded “turning.” The airplane subsequently began a rapid descent from which the pilot did not recover. 

Recorded weather closest to the accident site reported wind from the southwest at 15 kts, with gusts to 23 kts, rain, and a cloud ceiling of 1,100 ft above ground level (agl). Multiple AIRMETS and SIGMETS were in effect throughout the planned route of flight, and areas of moderate to severe icing were forecast. The airplane flew its descent in instrument meteorological conditions and moderate to severe icing conditions, including supercooled liquid droplets (SLD). 

Given the conditions, the airplane likely encountered serious icing during the descent. The pilot continued to use the airplane’s autopilot system while flying in sustained moderate to severe icing conditions. It is likely that either the autopilot masked the effects of the ice accretion on the airframe until it either reached its limits of use and disengaged at a low attitude or that it remained engaged until the airplane exceeded its critical angle of attack and entered an aerodynamic stall. The sudden onset of a rapid descent and subsequent near-vertical impact are consistent with a loss of control due to an aerodynamic stall. 

Postaccident examination of the airframe and engines revealed no evidence of any preexisting mechanical failures or anomalies that would have precluded normal operation. 

Medical review indicated that the pilot had used a cannabis product and it is possible that he could have been experiencing associated impairing effects at the time of the accident. However, the exact timing of his last cannabis use or level of impairment could not be determined from muscle tissue results alone.

- Probable Cause: The pilot’s continued use of the airplane’s autopilot after flight into moderate to severe icing conditions, which resulted in an exceedance of the airplane’s critical angle of attack and an aerodynamic stall.

Loss of control in flight: Rockwell Aero Commander 690A, N690BM, fatal accident occurred on May 5, 2024, near Palmyra, Virginia

• Location: Palmyra, Virginia
• Accident Number: ERA24FA209
• Date & Time: May 5, 2024, 08:54 Local
• Registration: N690BM
• Aircraft: ROCKWELL INTERNATIONAL 690A
• Aircraft Damage: Destroyed
• 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/194204/pdf

https://data.ntsb.gov/Docket?ProjectID=194204

On May 5, 2024, about 0854 eastern daylight time, a Rockwell International 690A, N690BM, was destroyed when it was involved in an accident near Palmyra, Virginia. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The airplane was in cruise flight at 20,000 ft on an instrument flight rules (IFR) cross-country flight when the pilot reversed course. When an air traffic controller queried the pilot, he replied, “we have lost…we need to climb.” The controller then asked the pilot, “what is your issue?” and the pilot responded, “we have lost autopilot.” There were no further communications received from the pilot and radar contact with the airplane was lost shortly thereafter. A witness who saw the airplane as it descended toward ground impact described that it was on fire.

The wreckage of the airplane was heavily fragmented and scattered amongst a wooded area, with a debris path over 3 miles long. The left wing, left engine, left propeller, and empennage were heavily burnt and found at the main wreckage site. The right wing was separated at the wing root and was found 1/4-mile north of the main wreckage. The right wing was fire damaged, and the right engine and right propeller were not located. The vertical and horizontal stabilizers were found about 3/4-mile north of the main wreckage. All fractures exhibited overstress features consistent with an in-flight breakup. Mapping of the wreckage indicated that the tail components likely separated first, followed by the right wing. This structural failure resulted in the horizontal and vertical stabilizers deforming and subsequently separating from the airplane. The lack of heat damage indicated that this separation occurred before the fire and that the inflight fire observed by the witness was likely a result of the inflight breakup. No evidence of any mechanical malfunctions or failures that would have preceded the inflight breakup was found during the postaccident wreckage examination.

Review of data provided by a preflight planning application vendor revealed that before the accident flight, the pilot filed an IFR flight plan and received a weather briefing. The briefing included an AIRMET for moderate icing with the freezing level between 9,000 and 13,000 ft, with tops at 24,000 ft, which included a portion of the intended route of flight. This AIRMET was active at the time of the accident. Satellite imagery of the accident area and upper air sounding model data depicted cloudy, instrument meteorological conditions across the region from the surface to above 30,000 ft. Upper air data and computer modeling also identified the potential for some icing as the airplane climbed above 11,000 ft, and it is possible that some trace icing could have accumulated on the airplane’s structure during this time. Weather radar reflectivity values indicated that along the final portion of the accident flight path, the potential for an encounter with more significant structural airframe icing was greater, though the severity of that icing could not be definitively quantified.

The airplane was equipped with de-ice boots on the leading edges of the wings, horizontal stabilizer, and vertical stabilizer. Most of the components of the airplane’s de-ice system were destroyed during the accident sequence and could not be examined. Review of maintenance logbooks did not reveal evidence of any anomalies or preexisting discrepancies that would have precluded normal operation of the de-ice system before the accident flight.

The pilot’s statement to air traffic control that he had “lost the autopilot,” shortly before radar contact with the airplane was lost and the airplane broke up in flight, suggest that he may have been experiencing difficulty controlling the airplane, either with or without the aid of the autopilot. The airplane’s pilot’s operating handbook contained an airworthiness directive (AD) that explicitly warned pilots who encountered certain types of structural icing in flight not to utilize the autopilot, as it could mask tactile cues indicative of adverse changes in the airplane’s handling characteristics. Given this information, it is likely that the pilot’s loss of control that ultimately resulted in the airplane’s inflight breakup was preceded by an accumulation of structural ice that altered the airplane’s handling characteristics in a way that the pilot had not anticipated and was unable to recover from.

- Probable Cause: The pilot’s loss of control following an encounter with structural icing, which resulted in an inflight breakup of the airplane.

VFR encounter with IMC: Extra EA 300/L, N22MW, fatal accident occurred on May 19, 2024, near Bandera State Airport (4W0), Bandera, Washington

• Location: Bandera, Washington 
• Accident Number: WPR24FA156 
• Date & Time: May 19, 2024, 16:49 Local 
• Registration: N22MW 
• Aircraft: EXTRA FLUGZEUGBAU GMBH EA 300/L 
• Aircraft Damage: Substantial 
• Defining Event: VFR encounter with IMC 
• Injuries: 1 Fatal 
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194296/pdf

https://data.ntsb.gov/Docket?ProjectID=194296

On May 19, 2024, at 1649 Pacific daylight time, an Extra Flugzeugbau GMBH EA 300/L airplane, N22MW, was substantially damaged when it was involved in an accident near Bandera, Washington. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The non-instrument-rated pilot departed for the destination airport to attend an aerobatic camp. The airplane followed an interstate through a mountain pass while generally maintaining an altitude of 1,500 ft above ground level (agl). As the airplane continued along the canyon, it began to climb while its airspeed slowed, likely the pilot’s response to entering an area of higher terrain while avoiding clouds. The airplane reached an altitude of about 7,000 ft mean sea level (msl) and an airspeed of 103 kts. The airplane began descending and its speed increased to over 185 kts. The airplane then leveled off briefly before beginning a steeper descent. The airplane then made a 90° left turn and the airspeed decreased while it continued the descent. The airplane impacted terrain in a near-vertical attitude. 

Postaccident examination of the wreckage revealed no evidence of a mechanical malfunction or failure. The examination found evidence consistent with the pilot, who was wearing a parachute, having his seatbelt fastened at impact, which indicates he did not attempt to bail out and suggests he did not perceive the airplane to be uncontrollable. 

Weather data indicated that, during the last 2 minutes of flight, the airplane was likely operating in instrument meteorological conditions above 3,000 ft msl and encountered icing conditions above 5,400 ft. Forecast information applicable to the accident time included moderate icing above 5,000 ft msl and mountain obscuration due to clouds and mist. There is no record of the pilot obtaining a weather briefing before departure. However, he had commented to the owner of the accident airplane that he might not be able to complete the flight as planned due to weather, indicating an awareness of potential overcast conditions. The pilot had flown through the pass on numerous occasions and likely felt comfortable with the route. 

The altitude and airspeed changes during the final 2 minutes of flight are consistent with the pilot attempting to remain clear of clouds while maintaining terrain clearance. After the airplane climbed, it likely encountered icing conditions. Although the reason for the pilot’s left turn could not be determined, the turn occurred while the airplane was in the cloud layer and likely accumulating ice, and it is possible he was attempting to reverse course while descending. The decrease in altitude while approaching the mountain peak, the drastic changes in airspeed, and then the sharp left turn followed by a sudden descent are consistent with the pilot becoming spatially disoriented and entering an aerodynamic stall. 

The pilot held the required FAA waiver for the aerobatic camp and was the only person authorized to activate the aerobatic area. This responsibility may have created self-induced pressure to complete the flight despite the adverse weather conditions.

- Probable Cause: The pilot’s decision to continue flight into icing conditions and inclement weather, which likely led to spatial disorientation when he attempted to divert from the planned course to the destination airport.

Loss of engine power (total): Beechcraft V35A Bonanza, N150WR, fatal accident occurred on June 7, 2024, in Arvada, Colorado

• Location: Arvada, Colorado 
• Accident Number: CEN24FA212 
• Date & Time: June 7, 2024, 09:30 Local 
• Registration: N150WR Aircraft: Beech V35A 
• Aircraft Damage: Destroyed 
• Defining Event: Loss of engine power (total) 
• Injuries: 1 Fatal, 2 Serious, 1 None 
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194416/pdf

https://data.ntsb.gov/Docket?ProjectID=194416

On June 7, 2024, about 0930 mountain daylight time, a Beech V35A airplane, N150WR, was destroyed when it was involved in an accident near Arvada, Colorado. The pilot was not injured. Two passengers sustained serious injuries, and a third passenger was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot reported that shortly after takeoff he noticed a slight drop in engine manifold pressure, but the airplane was still able to climb. He chose to divert to a nearby airport, and shortly thereafter, noticed that the oil pressure caution light had illuminated and oil pressure was rapidly decreasing. The engine subsequently lost total power. The pilot performed a forced landing on a residential street, during which the airplane impacted a tree and a parked pickup truck. The airplane was consumed by a postimpact fire. 

Examination of the airplane after it was recovered from the accident site revealed one missing bolt and three loose bolts associated with the oil line adapter fittings on the engine turbocharger. Police photos confirmed that the missing bolt was missing from the top oil line fitting at the accident site before the wreckage was moved. Three witnesses along the route of flight saw smoke emanating from the airplane, consistent with leaking oil contacting hot exhaust components during the flight. 

An engine examination revealed signatures consistent with an oil starvation event. The No. 5 connecting rod separated from the crankshaft, and the No. 5 connecting rod journal exhibited lubrication distress and smeared bearing material. The other connecting rod journals and main bearing journals showed varying degrees of discoloration from heat and lubrication distress. 

The engine oil and filter were replaced in the days before the accident. Additionally, the maintenance technician also replaced exhaust/muffler hardware in the vicinity of the missing and loose oil line fitting bolts; however, this would not have required loosening the oil line fitting bolts. The technician stated that there were no fluid leaks identified during a postmaintenance engine run and leak check.

The pilot reported that when he retrieved the airplane after maintenance, he checked the oil and performed a thorough preflight inspection before takeoff and did not observe any discrepancies during a 50-mile flight the day before the accident.

Based on the available evidence, the engine lost total power due to an oil starvation event as a result of the loose turbocharger oil line fittings, which allowed for an oil leak. Although the engine had undergone recent maintenance in the vicinity of the loose oil line fittings, the associated maintenance tasks did not require the those fittings to be loosened or removed. As such, the investigation could not conclusively determine how and when the oil line fittings became loose.

- Probable Cause: A total loss of engine power due to oil starvation as a result of loose turbocharger oil line fittings.

Aircraft structural failure: Bailey-Moyes Dragonfly, UNREG, fatal accident occurred on April 19, 2024, at Sheets Airport (FA42), Groveland, Florida

• Location: Groveland, Florida
• Accident Number: ERA24LA185
• Date & Time: April 19, 2024, 13:30 Local
• Registration: UNREG Aircraft: Bailey-Moyes Dragonfly
• Aircraft Damage: Substantial
• Defining Event: Aircraft structural failure
• Injuries: 1 Fatal
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194119/pdf

https://data.ntsb.gov/Docket?ProjectID=194119

On April 19, 2024, about 1330 eastern daylight time, an unregistered Bailey-Moyes Dragonfly airplane was substantially damaged when it was involved in an accident at Sheets Airport (FA42), Groveland, Florida. The private pilot was fatally injured. The flight was operated under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. 

According to witnesses, the airplane departed and climbed to an altitude about 200 to 300 ft above ground level and then turned before the right wing “folded upward” and the airplane descended in a spiral to the ground. Postaccident examination revealed that the right lower wing strut attachment was not properly assembled; the bolt intended to connect the wing strut block to the fuselage bulkhead was threaded through the fuselage structure and tightened, but had not passed through the hole in the strut block, resulting in no load-bearing connection between the wing strut and the fuselage. The absence of deformation or damage to the bolt and wing strut block at the attachment point was consistent with the improper installation of the bolt. 

Without the structural support of the right lower wing strut, the wing was unable to sustain the aerodynamic loads encountered during the initial climb, resulting in an in-flight structural failure of the right wing. The accident flight was the airplane’s first flight since it was assembled by the pilot. The airplane was unregistered and had not been issued an airworthiness certificate or operating limitations, nor had it been inspected by a designated airworthiness representative or an FAA inspector before the flight. 

- Probable Cause: The pilot’s improper installation and inspection of the right lower wing strut attachment bolt, which resulted in the inflight failure of the right wing.

Unknown or undetermined: Piper PA-18-150 Super Cub, N1880P, fatal accident occurred on December 8, 2023, near Anchor Point, Alaska

• Location: Anchor Point, Alaska
• Accident Number: ANC24FA008
• Date & Time: December 8, 2023, 13:12 Local
• Registration: N1880P
• Aircraft: Piper PA-18-150
• Aircraft Damage: Destroyed
• Defining Event: Unknown or undetermined
• Injuries: 2 Fatal
• Flight Conducted Under: Part 91: General aviation - Personal

https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/193500/pdf

https://data.ntsb.gov/Docket?ProjectID=193500 

On December 8, 2023, about 1312 Alaska standard time, a Piper PA-18-150 airplane, N1880P, was destroyed when it was involved in an accident near Anchor Point, Alaska. The pilot and passenger were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

The pilot was conducting a cross-country personal flight with one passenger. After takeoff, the airplane climbed to altitude to overfly a large body of water. After crossing over the body of water the airplane began a descent. Subsequently, a vehicle dash-mounted camera captured about 7 seconds of video of the airplane falling vertically in an inverted flat spin with the left wing’s outboard section partially separated from the airplane, folded in a V-shape, before impact. The recorded video did not capture the initiating event. Review of flight track data from the airplane’s GPS indicated the pilot initiated a descent of about 1,000 ft per minute (fpm) as the airplane neared the shoreline. The descent rate remained steady until the airplane crossed over the shoreline at an altitude of about 4,500 ft mean sea level (msl), when the descent rate increased to about 4,000 fpm. The airplane came to rest in low brush and trees in an inverted attitude.

All major airframe and engine components were recovered at the impact site. Control continuity was established between the cockpit flight controls and their respective control surfaces. Examination of the engine revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation.

Examination of the left wing revealed a portion of the leading edge skin was flattened and fractured into two pieces. There was mechanical tearing on the upper portion of the aluminum leading edge skin and the leading edge ribs were crushed against the forward spar in this area. The fabric skin covering the aluminum leading edge skin in this area was torn and ripped, coincident with the mechanical damage. Multiple linear, parallel gouges, cuts, and scuffs were oriented aft and inboard in the wing fabric around the area that was torn. There was no evidence of transferred material in these marks, and no evidence of tree debris around the leading edge damage. The mechanical damage to the left wing’s leading edge and the linear, parallel witness marks were consistent with impact by an object.

The examined fracture surfaces had an angled, dull, grainy appearance consistent with overstress separation. The left wing had no obvious corrosion, and it was assembled correctly and was intact before the initiating event, with no pre-existing conditions that would compromise its strength. The deformation of the left wing’s leading edge and spars and the fracture of the left wing spars were not consistent with normal in-flight loads. The separation of the propeller tip from overstress was consistent with impact separation while under power.

Based on physical evidence, it is likely that the leading edge of the left wing was impacted, at an undetermined time, which deformed the forward and aft spars and fractured the forward spar. Aerodynamic loads then twisted the left wing’s outboard section leading edge down and fractured the rear spar, partially separating the left wing from the fuselage. The left wing’s outboard section remained attached to the lift struts, and aerodynamic loads deformed it into a V-shape about the strut attach points. The location and orientation of silver paint transfer marks indicate the upper surface of the left wing’s outboard section likely impacted the airplane’s left ski as the wing fractured and partially separated. This sequence rendered the airplane uncontrollable and resulted in it entering an inverted flat spin.

Examination of the wing showed impact signatures consistent with a glancing impact, but the timing of the contact could not be determined. Based on the available evidence, investigators could not establish whether the damage occurred on the ground, in flight, or immediately before the accident. If a second aircraft had contacted the accident airplane, it is possible that the damage would have been minor enough for continued flight and a normal landing. However, aside from an unverified radio transmission or phone call, the investigation found no evidence that another aircraft was near the accident airplane at the time of the event.

- Probable Cause: An impact to the left wing, at an undetermined time, for reasons that could not be determined, which partially separated the left wing and rendered the airplane uncontrollable.