ERA25FA082

The pilot had completed a check out flight earlier in the day, and the accident flight was her first solo flight in the accident airplane. She departed the airport where the airplane was based, flew to another airport and performed a touch-and-go landing, then flew to the airport nearest the accident site where she again performed a touch-and-go landing. Upon departure from that airport, while making a turn likely to return to the airport where the airplane was based, the pilot transmitted a mayday call over the common traffic advisory frequency. In the mayday call the pilot reported a loss of control. The airplane then began a descending right turn until impacting a tree and the ground in a mango orchard. Postaccident examination of the wreckage revealed that the right aileron carry through cable had fractured, and that 62% of strands on one side of the fracture and 60% of strands on the other side of the fracture failed due to wear. The other strands on the cable failed due to overstress. Based on these findings, it is likely that the wear of this cable progressed to the point where it could no longer support the stresses of flight, resulting in the in-flight failure of the right aileron carry through cable. With this cable failure, the closed loop aileron system would be interrupted and the control inputs from the pilot would only tension a single cable run. This would result in the aileron on the unloaded side tending to float toward its zero hinge-moment (aerodynamically neutral) position, while the aileron on the loaded side would remain responsive to pilot input. The pilot would retain partial roll control; however, control effectiveness would be reduced because only the lift-increasing aileron would be actively driven, while the opposing surface would not provide a corresponding aerodynamic response. Due to a lack of available flight data, this investigation could not determine how much control the pilot would retain, and if the pilot would have retained enough control to make a safe landing. A review of the airplane’s maintenance logbooks found that the left aileron carry through cable had been replaced about 6 months prior to the accident while the airplane was undergoing an annual inspection. The maintenance log entry documenting the inspection and the cable replacement did not note a reason that the cable was replaced. Given the degree of wear observed on the right aileron cable that was observed after the accident, it is likely that the condition had developed over a prolonged period of time. These wear indications, like fractured cable strands, should have prompted maintenance personnel to replace the cable prior to its failure on the accident flight. The results of postmortem toxicological testing indicated that the pilot had used the sedating antihistamine medication diphenhydramine, but provided no clear evidence that impairing effects of that medication were impairing the pilot at the time of the accident. The toxicologicaltesting also detected ethanol in blood, but not in vitreous fluid, indicating that the detected ethanol likely was from postmortem sources, and not alcohol consumption.

The airframe manufacturer was asked what effect a failure of the aileron carry through cable would have on the aileron control system. They responded, stating: On a Cessna 172S, a disconnection of the aft most wing (aileron) cable would interrupt the closed-loop control system. In this condition, control wheel inputs would tension only a single cable run, effectively transmitting load to one wing in both directions of wheel travel. As a result, the aileron on the unloaded side would tend to float toward its zero hinge-moment (aerodynamically neutral) position, while the aileron on the loaded side would remain responsive to pilot input. This condition would occur in both left and right roll commands. The pilot would retain partial roll control; however, control effectiveness would be reduced because only the lift-increasing aileron would be actively driven, while the opposing surface would not provide a corresponding aerodynamic response. A review of the Cessna Model 172 Maintenance Manual showed the right aileron carry through cable was a straight run from the right aileron bellcrank to the turnbuckle where it connected to the left aileron carry through cable. It also showed that the right aileron carry through cable did not interact with the pulley in the center fuselage. FAA aircraft registration records showed that the airplane was purchased by the flight school in 2012. A review of maintenance records showed that the airplane’s most recent annual inspection was completed on June 7, 2024, at an airframe total time of 3,271 flight hours. The entry documenting that inspection also noted that the left wing aileron carry through cable was replaced with a new flight control cable; the reason for the replacement was not stated. The available maintenance logbooks did not show the right wing aileron carry through cable had ever been replaced. An FAA inspector performed a ramp inspection of the accident airplane on July 5, 2024, about 1 month after the airplane’s most recent annual inspection, and during this inspection they noted corrosion in 7 of the 12 discrepancies, including on the right wing. The airplane maintenance records showed the items noted during the inspection were addressed on July 18, 2024, by removing the superficial corrosion, chemically treating the areas, applying primer, and applying paint. The airplane’s most recent 100-hour inspection was completed on October 23, 2024, at an airframe total time of 3,471 flight hours. On December 20, 2024, about 1400 Atlantic standard time, a Cessna 172S, N22088, was destroyed when it was involved in an accident near Cintrona, Puerto Rico. The private pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The airplane departed Fernando Luis Ribas Dominicci Airport (TJIG), San Juan, Puerto Rico, where the airplane was based, and ADS-B-derived track data showed that it continued to Antonio Rivera Rodríguez Airport (TJVQ), Isla deVieques, Puerto Rico, where the pilot performed an approach consistent with a touch-and-go landing. The airplane then proceeded to Mercedita Airport (TJPS), Ponce, Puerto Rico where the pilot performed another touch-and-go landing before departing to the north. Shortly after departure from TJPS, a recording of the airport’s common traffic advisory frequency captured a transmission from the pilot which stated, “Mayday Mayday… loss of control…088 Cessna.” This was followed by a final Mayday transmission about 20 seconds later. ADS-B track data, after departure from TJPS, showed the airplane began a left turn towards the north at 1354:19. At 1355:42 the airplane reached a maximum barometric altitude of 2,300 ft mean sea level on a heading of about 021°. At 1355:43 the airplane began a right turn and descent which continued until track data was lost. The last ADS-B track data point was located about 2 nm northeast of the departure end of runway 12 at TJPS and about 0.3 nm northeast of the accident site. At the last ADS-B data point the airplane was at a barometric altitude of 1,600 ft mean sea level and on a heading of about 133°. The Puerto Rico Institute of Forensic Sciences ruled the cause of death for the pilot as severe bodily trauma and the manner of death for the pilot as accident. The FAA Forensic Sciences Laboratory performed toxicological testing of postmortem specimens from the pilot. FAA testing detected ethanol at 0.103 g/dL in cavity blood. Ethanol was not detected in vitreous fluid. Diphenhydramine was detected in cavity blood and liver tissue. Postmortem toxicological testing by the Institute of Forensic Sciences detected ethanol at 0.1 g/dL in central blood and did not detect ethanol in vitreous fluid. Postmortem toxicological testing by NMS Labs performed at the request of the Institute of Forensic Sciences did not detect diphenhydramine in heart blood. Ethanol is the intoxicating alcohol in beer, wine, and liquor, and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance. FAA regulation imposes strict limits on flying after consuming ethanol, including a prohibition on piloting a civil aircraft while having a blood ethanol level of 0.04 g/dL or greater. Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol sometimes may be produced by microbes in a person’s body tissues and fluids after death. Typically, vitreous fluid is the specimen type best protected against microbial contamination, and therefore is less susceptible to postmortem ethanol production than are other specimen types. Diphenhydramine is a sedating antihistamine medication widely available over the counter in multiple sleep aids and cold and allergy products. Diphenhydramine can cause cognitive and psychomotor slowing and drowsiness, and often carries a warning about driving and operating machinery. FAA guidance indicates that pilots should not fly within 60 hours of using diphenhydramine, toallow time for it to be cleared from circulation. Diphenhydramine has significant potential for postmortem redistribution. The pilot held a private pilot certificate and was actively working towards an instrument rating. A review of the pilot’s logbook showed that she had received an endorsement for the instrument airplane practical test on December 4, 2024. The review also found that the pilot had only one previously logged flight in Puerto Rico, which was the day of the accident and in the accident airplane. This entry had a note that stated “Rental check Isla Grande Flying School.” A review of the pilot’s rental record, provided by the flight school from which the airplane was rented showed that the pilot had completed a check out flight with a company flight instructor, in the accident airplane, and completed a written test the day of the accident flight. The accident site was located in a mango orchard about 1.8 nm from the departure end of runway 12 at TJPS. There was debris strewn along a path that was about 360 ft-long, oriented on a magnetic heading of 345°, and at an elevation of 46 ft mean sea level. The initial impact point was about 15 ft up a mango tree. The initial ground impact scar was about 140 ft from the tree impact and contained pieces of wheel fairing embedded in the scar. The main impact crater, which contained the propeller, was about 30 ft from the initial ground impact scar. The tree next to the main impact crater contained pieces of wing leading edge and about a 6-inch diameter branch was impact-separated. The left wing and the left door post were wrapped around a tree about 48 ft past the main impact crater. A branch about 1 ft in diameter was impact-separated, and the tree contained pieces of fuselage and cabin in the canopy. The right wing and engine were located about 75 ft past the left wing and the path was strewn with engine and airframe components. The fuselage and empennage were located about 70 ft past the right wing and engine. The cockpit and all instruments/avionics were destroyed. Both wings, the engine, both horizontal stabilizers, and the vertical stabilizer were impact-separated and found along the debris path. The rudder control cables remained attached to the rudder flight control horn and were continuous to the rudder pedals. The elevator control was continuous from the flight control surface bellcrank to the cockpit bellcrank. The trim tab actuator was measured and equated to 5° tab trailing edge up. The flap motor was examined and when measured the jackscrew was consistent with the flaps being in the UP position. The fractured flight control cables were recovered for detailed metallurgical examination. The control column interconnect cable fracture ends displayed signatures consistent with tensile overload. The right wing aileron carry through cable fracture surfaces showed 62% wear on one side of the fracture and 60% wear on the other side of the fracture. The left aileron carry through cableremained intact. The right aileron direct drive cable fracture showed 16% of the fractured strands exhibiting wear. The left aileron direct drive cable fracture showed 39% of the fractured strands exhibited wear. The engine was impact-separated from the fuselage and was found about 150 ft from the initial ground impact scar. The engine exhibited significant impact damage and the induction and exhaust systems were destroyed by impact forces. Both magnetos were impact-separated and found along the debris path; the impulse couplings snapped when the drive was rotated by hand. The ignition key was found in the both position. All major accessories, except for the engine-driven fuel pump were impact separated and found strewn throughout the debris path. The engine-driven fuel pump remained secure to the accessory case. The propeller was buried about 8 inches in the dirt at the main impact crater. The propeller blades exhibited S bending, leading edge polishing, and chordwise scratching.