Mesnard Velocity Twin
Sandersville, Georgia/Injuries: 1 Fatal, 1 Serious
NTSB Report: ERA23LA32
The pilot, who held an airline pilot transport certificate and had logged approximately 21,000 flight hours, planned to do a cross-country flight in the twin-engine, amateur-built airplane. He was accompanied by a passenger. The pilot reported that the takeoff was normal, but at an altitude of approximately 500 feet, the right engine “failed hard.” The airplane began to roll to the right. The pilot added left rudder to arrest the roll but was unable to stop it, so he then added full left aileron. The airplane continued to roll right. The pilot then performed what he described as a “low yo-yo” maneuver, and he was able to regain control of the airplane. He reduced throttle on both engines to idle before pitching to maintain 85 knots, which was the simulated single-engine best rate of climb airspeed (VYSE) determined during flight testing. The pilot reported that the airplane could not climb at 85 knots, and he was too low to return to the airport, so the pilot went straight ahead and put the aircraft down in a small clearing in a swamp. The off-airport landing substantially damaged the fuselage, empennage, and both wings.
The postaccident examination of both engines and the flight controls found no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation.
However, the examination of the airplane’s wiring found the engine control unit (ECU) wiring from the ECU circuit breakers in the cockpit to the ECUs on the aft firewall was chafed, and multiple wires were severed in the vicinity of the main landing gear actuator piston track. The wires were not shielded or protected and were clamped to the side of an undamaged covered channel where the landing gear actuator piston ran along with multiple other wires and the aileron control rod. One power wire for the left ECU was severed, and both right ECU injector wires were severed. Multiple other wires in the same bundle exhibited cuts and chafing, likely a result of the main landing gear teeter bar rubbing against the wires when the landing gear was raised and lowered.
The ECU manufacturer reported that with both right ECU injector wires severed, there would be no power to the electronic fuel injectors for the right engine, and combustion would be lost.
The pilot reported that during the accident flight, he never attempted to feather the windmilling propeller of the right engine. Subsequently, the propeller controller would have continued to adjust the propeller blades to a fine pitch attitude in an attempt to maintain the set engine rpm until reaching the fine pitch stop. This adjustment toward fine pitch would greatly increase the drag produced by the propeller, and it is likely the unexpected drag the pilot reported experiencing following the loss of engine power.
The pilot stated that during his flight testing of the airplane, he did not shut an engine down in flight nor did he feather a propeller in flight, as he thought it was too much of a risk. Instead, he simulated single-engine operations by reducing an engine to idle with the propeller set to cruise. All single-engine flight testing was done in this configuration to include minimum controllable airspeed (VMC) and VYSE, and basic flight with a simulated loss of engine power to one engine. Due to the lack of flight testing with an engine shutdown, the investigation was unable to determine why the pilot experienced a loss of control even though the airplane remained above the VMC and VYSE.
Probable cause(s): A total loss of power in the right engine due to the right ECU injector wires being severed by the main landing gear actuator piston teeter bar as a result of a lack of clearance and protection of the wiring bundle.
Cessna 152/Cessna 172
Long Beach, California/Injuries: None
NTSB Report: WPR23LA298
The student pilot in a Cessna 152 reported that, after completing the engine start procedure checklist, he set the parking brake, and both he and the instructor placed their feet on the brake pedals. As both pilots looked down to plug in their headsets, the airplane rolled forward, striking the right wing of a Cessna 172 that was taxiing in front of them. As a result of the collision, the Cessna 172’s right wing was substantially damaged. The flight crews of both airplanes reported that there were no preaccident mechanical failures or malfunctions with their airplanes that would have precluded normal operation.
Probable cause(s): The flight instructor’s inattention during ground operations, which resulted in unintentional movement of the airplane and ground collision with another airplane.
Kitfox III
Scottsburg, Indiana/Injuries: 1 Serious
NTSB Report: CEN23LA381
The student pilot who did not have the required solo endorsement was attempting a personal flight in an airplane that lacked an airworthiness certificate. A witness to the accident flight stated that the student pilot performed a successful airplane run-up before takeoff. The airplane lifted off about halfway down the runway and climbed to about treetop level. A few seconds later, the right wing dropped, and the airplane descended in a nose-down attitude. The engine continued to operate after the impact until the witness turned the magnetos and fuel selector valve off. The airplane sustained substantial damage to the fuselage. The post-accident investigation did not find any mechanical issues.
Probable cause(s): The student pilot’s failure to maintain airplane control after takeoff resulted in an impact with terrain.
Piper PA-24-250
Oklahoma City/Injuries: 1 Serious
NTSB Report: CEN23FA360
The pilot was in cruise flight nearing the destination airport when the engine sustained a total loss of power. The pilot made a forced landing on a grassy slope on the left side of a highway. The aircraft struck a power line on the way down. The left main fuel cell and left auxiliary fuel cell on the left wing were breached and could not be functionally tested. The right main fuel cell did not contain any fuel, and the right auxiliary fuel cell was full of fuel. The fuel selector valve was set to the right main fuel cell. The postaccident examination of the airframe and engine did not detect any anomalies that would have precluded normal operation. The pilot told a friend that he received a low fuel warning light while operating on the right main fuel cell. The pilot switched to the left main fuel cell. However, engine power did not return, so he switched back to the right main fuel cell. Investigators were unable to ascertain what additional steps the pilot may have taken to restore engine power after initially switching to the left main fuel cell. The loss of engine power was likely due to fuel starvation, as there was adequate fuel remaining in the right auxiliary fuel cell.
Probable cause(s): The pilot’s mismanagement of fuel, which resulted in fuel starvation and a subsequent total loss of engine power.
Piper PA-28-161
Fort Pierce, Florida Injuries: 1 Fatal, 1 Serious
NTSB Report: ERA23FA340
Two flight instructors were taking part in a flight school-mandated proficiency check. The instructor in the left seat was employed by the flight school and was administering the check to the newly hired instructor in the right seat. The left-seat instructor stated that he was demonstrating an EASA [European Union Aviation Safety Agency] maneuver at the time of the accident. The maneuver was not a part of the operator’s instructor briefing sheet for the proficiency check. The maneuver involved a power-off aerodynamic stall and recovery without the use of engine power. The left-seat instructor described that he pitched the airplane up and entered a full aerodynamic stall with the engine power at idle. After the airplane stalled, he pitched down to get a glide airspeed of 73 knots to recover from the stall. He stated that during the recovery, with power at idle, the right wing departed the airplane, and the airplane banked abruptly to the right. The airplane then descended and impacted a small building that housed a recreational vehicle. Both wings and the horizontal stabilator separated from the airplane in flight and were located about 600-700 feet away from the fuselage.
A performance study using ADS-B data and a forensic metallurgical examination of the fractured wing surfaces were conducted following the accident. The performance study found that the airplane made four steep turns in the final few minutes of recorded data before the in-flight breakup. The final two 180-degree turns observed in the flight track data had a significantly smaller turn radius compared to previous maneuvers. The second-to-last steep turn had a radius of 280 feet, and the airplane accelerated to over 100 knots airspeed while still in the turn, resulting in a calculated bank angle of over 70 degrees left wing down. The final turn started with a radius of 200 feet that tightened as the airplane accelerated. With the airplane’s true airspeed at 99 knots, for a 200-foot turn radius, the resulting bank angle was over 75 degrees left wing down. These calculated bank angles, and thus the calculation of any resulting load factors, derived from ADS-B data, were approximate values that were dependent upon the accuracy of the recorded GPS data.
The forensic metallurgical examination found that the left and right main spars fractured in ductile overstress following wing loads that exceeded the design capability of the airplane. The right wing likely fractured first, and the local deformation associated with the spar fracture was consistent with the upward loading on the wing. The left wing failure was secondary, showing local downward deformation at the fracture location. The left wing failure likely occurred due to a sudden elastic relaxation of the overloaded left wing in response to the rapid load change from the right wing failure, combined with downward air loads on the left wing associated with a subsequent roll to the right from the loss of lift on the right side of the airplane.
Further metallurgical examination of both the right and left wing main spar lower caps found that fatigue cracks initiated in areas of fretting damage. The uniform deformation and upward bending on both sides of the spar box were indicative of a steep turn maneuver that grossly exceeded the structural limitations of the airplane. The airplane was operating in the normal category at the time of the accident. The airplane’s pilot operating handbook prohibited aerobatic maneuvers, which included turns beyond 60 degrees of bank, and included a load limit of 3.8g while operating in the normal category.
The surviving instructor reported that he was flying the airplane at the time of the inflight breakup, but his recollection of the last moments of flight and the maneuver being demonstrated was not consistent with the steep turns identified in the ADS-B performance study.
Probable cause(s): The left seat instructor’s intentional maneuvering of the airplane in an aerobatic steep turn for which it was not approved, which resulted in an exceedance of the structural limitations of the airplane and an in-flight breakup.
Cessna T210M
Indian Creek, Idaho/Injuries: None
NTSB Report: WPR23LA318
The pilot, who had logged approximately 1,369 hours of flight, was conducting a Part 135 flight with four passengers on board. During cruise flight, the airplane’s engine began to run rough and then subsequently lost power. His attempts to restore power were unsuccessful. Due to high airspeed and low altitude, the pilot elected to land gear up on a dirt airstrip, which resulted in substantial damage to the underside of the airplane. The postaccident examination revealed 18 gallons of fuel in the right fuel tank, and the left fuel tank was void of fuel. Neither fuel tank was breached. The operator of the airplane reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The NTSB report did not include information on how much fuel had been onboard prior to takeoff or the duration of the flight before the engine roughness.
Probable cause(s): The pilot’s improper fuel management, which resulted in fuel starvation and gear-up landing on a dirt airstrip.
