Monday the 6th of April, 2026

NTSB Final Report: Cozy Mark IV

The Airplane Landed Short Of The Runway Threshold And Its Nose Landing Gear Separated As The Airplane Transitioned Onto The Asphalt Runway

Location: Gonzales, Texas Accident Number: CEN24LA141
Date & Time: March 25, 2024, 18:53 Local Registration: N20MN
Aircraft: Cozy Mark IV Aircraft Damage: Substantial
Defining Event: Loss of engine power (total) Injuries: 1 None
Flight Conducted Under: Part 91: General aviation - Personal

Analysis: While enroute, at 9,500 ft above mean sea level (msl), the engine lost all power. After multiple attempts to restart the engine, the pilot executed a forced landing to a nearby airport. The airplane landed short of the runway threshold and its nose landing gear separated as the airplane transitioned onto the asphalt runway. The left wing and left canard sustained substantial damage.

Postaccident examination of the engine revealed that the left crankshaft idler gear shaft separated from its attach points, which prevented the crankshaft idler gear from engaging its corresponding crankshaft and camshaft gears. The disengagement prevented camshaft rotation and valvetrain timing to the crankshaft. The left crankshaft idler gear’s attachment hardware were both separated into two sections from abrasion. The capscrew was lockwired to the idler shaft but no lockwire was observed through the stud and slotted shear nut.

It is likely that maintenance personnel did not follow the engine manufacturer’s service instructions and undertorqued the fasteners during installation, resulting in insufficient clamping force. Additionally, the absence of lockwire likely permitted the shear nut to back off during engine operation. Because the airplane’s maintenance records were not available for review, the investigation was not able to identify when the crankshaft idler gear was last serviced.

Probable Cause and Findings: The National Transportation Safety Board determines the probable cause(s) of this accident to be -- Maintenance personnel’s failure to properly torque the crankshaft idler gear hardware according to the engine manufacturer’s service instructions, which resulted in separation of the crankshaft idler gear’s fasteners and disengagement of the camshaft, crankshaft, and crankshaft idler gear and a subsequent total loss of engine power.

FMI: www.ntsb.gov

 

 

NTSB Final Report: James E Davidson Jr RANS S7S Courier

On Previous Flights, The Engine Had Produced Less Power Than The Pilot Expected

Location: Benson, Arizona Accident Number: WPR24LA130
Date & Time: April 22, 2024, 09:42 Local Registration: N599YY
Aircraft: James E Davidson Jr RANS S7S Courier Aircraft Damage: Substantial
Defining Event: Fuel starvation Injuries: 1 None
Flight Conducted Under: Part 91: General aviation - Personal

Analysis: The pilot was evaluating the airplane’s engine performance with a different fuel after changes were made to the fuel system. Shortly after a normal takeoff, the pilot noticed a low fuel pressure warning. The engine subsequently sustained a partial and then total loss of power. The pilot restarted the engine, and it momentarily produced power. As he advanced the throttle, the engine again stopped producing power. During an off-airport landing, the main landing gear collapsed.

On previous flights, the engine had produced less power than the pilot expected. In response, he performed an engine examination and observed lead deposits on the exhaust valves. He contacted the engine manufacturer, who recommended switching from 100LL avgas to unleaded auto fuel. The pilot then created a mixture of winter-blend auto fuel and a small, precise amount of 100LL avgas.

An examination of the engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. Examination of the fuel system revealed that the inside diameter of the fuel supply and return lines were smaller than recommended by the engine manufacturer. This undersized condition limited the volume of fuel available to the engine.

A small fuel leak was discovered at an exit fitting in one of the fuel pumps. Investigators could not determine if the leak existed before the accident or if it was a result of impact forces. Additionally, the vent tube in the left-wing fuel tank was obstructed and did not permit airflow until investigators inserted a small wire several inches into the tube, after which the vent permitted air passage.

Accident flight data recorded by the airplane’s engine monitoring device revealed that the fuel pressure and flow both declined slowly as the flight progressed and became increasingly erratic. Shortly thereafter, a sudden and complete loss of both fuel pressure and flow occurred. When the pilot attempted to restart the engine, the available fuel pressure and flow was insufficient to sustain engine operation. Recorded data from the flight was consistent with air bubbles present in the fuel system, followed by fuel starvation due to vapor lock. After an operational test of the engine, several firewall-mounted fuel-system components (including the gascolator, fuel filters, electric fuel pumps, and associated metal fuel lines) that had been positioned near the engine exhaust system remained hot for more than 20 minutes after engine shutdown. Under these heat-soaked conditions, investigators noted that the fuel pumps required an extended period to achieve priming, and the fuel exiting the pumps initially appeared cloudy and aerated before gradually clearing as normal pressure and flow were restored. The pumps emitted abnormal noises consistent with cavitation during the period when cloudy, vapor-entrained fuel was present.

The locally procured auto fuel was a winter blend, which is formulated in a manner that makes it susceptible to vaporization at warmer fuel temperatures. Because the fuel was routed through metal fuel system components exposed to exhaust heat, the fuel in the system was likely heated to a temperature that resulted in vaporization. Although the investigation also found a small leak at a fuel line exit fitting and a blocked vent tube in the left-wing fuel tank, the engine data and postaccident engine testing was consistent with fuel vaporization. The vaporization of the fuel likely led to a vapor-lock condition and subsequent fuel starvation.

Probable Cause and Findings: The National Transportation Safety Board determines the probable cause(s) of this accident to be -- The pilot’s unintentional use of a winter-blend fuel that was susceptible to vaporization, which resulted in fuel starvation and a loss of engine power due to vapor lock. Contributing to the accident was the airplane’s undersized fuel lines, which limited the available fuel flow and volume.

FMI: www.ntsb.gov

 

 

NTSB Prelim: Experimental Homebuilt Airshark

One Of The Pilots Decided To Conduct A Local Flight To Verify The Airplane Was Performing Normally

Location: Statesboro, GA Accident Number: CEN26FA147
Date & Time: March 25, 2026, 14:53 Local Registration: N220AS
Aircraft: Experimental Homebuilt Airshark Injuries: 1 Fatal
Flight Conducted Under: Part 91: General aviation - Personal

On March 25, 2026, about 1453 eastern daylight time, an experimental homebuilt Airshark airplane, N220AS, was substantially damaged when it was involved in an accident near Statesboro, Georgia. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91personal flight.

The airplane was being prepared for a ferry flight from Statesboro, Georgia, to Carrollton, Georgia, when one of the pilots decided to conduct a local flight to verify the airplane was performing normally before beginning the cross-country flight. Local authorities received a cell phone crash alert at 1453. First responders located the wreckage in a wheat field where it came to rest inverted.

The airplane struck a tree in about a 14° right wing low attitude about 42 feet above the ground on a 062° magnetic heading. A ground scar at 215 feet forward from the tree appeared to have been created by a propeller strike. At 218 feet from the tree, a large ground scar led up to the airplane which came to rest inverted 245 feet from the tree. An impression in the soil to the left of the large groundscar was consistent with the right wing as evidenced by the green position light lens found at the outer end of the impression.

An on site examination of the wreckage revealed no anomalies were found with the flight control system or flight control surfaces. Flight control continuity was verified for the ailerons, rudder, and elevators.

The airplane was reported to have been fueled to capacity (118 gallons) before the accident flight. The fuel selector in the cockpit was in the left fuel tank position. Both fuel tanks were breached, and the surrounding vegetation was yellow in the field where the wreckage came to rest. The right fuel cap and its receptacle were separated from the wing but present in the debris field next to the airplane. Both fuel caps were present and secure in their receptacles.

To facilitate viewing the fuel tank finger screens with a borescope, access holes were made in the wings near the wing root in the top wing skin. The right fuel tank finger screen was free of obstructions. The left fuel tank finger screen was corroded and appeared to be 30 to 40% obstructed. The obstruction’s appearance was consistent with solder used to manufacture the finger screen’s seam and end cap and did not appear to be foreign object debris from the fuel tank. Both fuel tanks were clean and free of debris in the area around the finger screens.

The airplane was equipped with a bail type gascolator and an inline paper element style fuel filter. The bail type gascolator bowl was sampled and blue liquid with an odor consistent with 100LL aviation fuel was collected in a container. When water-indicating paste was applied to the fuel, there was a small amount of water present (a tiny portion of the paste turned bright red). The gascolator bowl was removed and there was about a ½ teaspoon of water present.

There was no filtering element or screen present in the gascolator bowl, and rust was present in the bottom of the bowl.

The paper style fuel filter was removed from its mount. It contained blue liquid consistent with the appearance and odor of 100LL aviation fuel. Water-indicating paste was added to the fuel. It did not indicate any water was present. The paper filter element was generally clean. Some rust and corrosion were present in the metal housing.

No leaks or anomalies were noted along the fuel lines in the airframe. Fuel was present in the engine compartment fuel lines and all the engine fuel system components examined. The fuel injector servo and fuel flow divider were disassembled and no anomalies were noted. The engine driven fuel pump was removed from the engine and produced air at the outlet port when it was actuated by hand. The unit was disassembled and no anomalies were noted.

The engine valve covers were removed and crankshaft continuity to the rear gears and to the valvetrain was confirmed. Compression and suction were observed from all six cylinders. A wire screen covered the fuel injector servo; corrosion and some trapped debris were present. No other induction air filtration system was present for this installation. Both magnetos exhibited impact damage. The left magneto did not produce spark when rotated by hand. The right magneto produced spark when it was rotated with a drill. The spark plug electrodes exhibited dark grey coloration and normal wear signatures. The No. 3 bottom spark plug electrodes were oil soaked. The ignition harness was secure and no damage was noted. Oil was observed in the engine. The oil suction screen contained about ¼ teaspoon of dark granular material. The oil filter was not examined due to impact damage.

The propeller remained attached to the engine. One blade was bent aft about 20° about 10 inches from its tip. One blade was curved aft about 50° about 12 inches from its tip. One blade was curved aft about 80° about 12 inches from its tip. All three blades were twisted in varying amounts towards their respective blade faces.

A Levil Flight Aviation broadcasting outer module (BOM) was found on the ground next to the airplane, which had been attached to one of the wing’s lower wing skin access covers. The unit is capable of providing flight data wirelessly to a phone or tablet in the cockpit when properly configured. The unit was reported to have been installed the day of the accident flight, but the contracted ferry flight pilot declined to configure the device due to time constraints. According to the manufacturer’s website, the unit may contain a flash memory card. The unit was retained for further examination.

FMI: www.ntsb.gov