Event CEN24LA012

Factual narrative

On October 15, 2023, at 0900 central daylight time, a Zant TVAP-4, N42VZ, was involved in an accident near Franksville, Wisconsin. The airplane sustained substantial damage. The pilot was uninjured. The airplane was operated under Title 14 Code of Federal Regulations Part 91 as a personal flight. The pilot, who was the airplane owner, stated that the airplane sustained a total loss of engine power while climbing through 200 ft above ground level. The pilot then performed a forced landing on a field near the departure end of the runway. During the landing, the airplane rolled for about 100 ft before the landing gear dug into soft terrain resulting in a nose over of the airplane. The airplane sustained substantial damage to both wings. The airplane was equipped with a Generation 3 Ignition (G3i), which is an electronic ignition control system that is interfaced with the engine’s magneto ignition system on homebuilt, experimental aircraft. The G3i system is comprised of a MSD Ignition Multiple Spark Discharge (Ignition Amplifier) unit and a G3i Ignition Interface unit. Each unit was installed with a 7.5-amp fuse; however, the G3i Installation Manual (Series-1 and Series-2) did not call for the installation of fuses for either unit. The G3i Installation Manual stated, in part: “The G3i module interfaces the aircraft magnetos with (MST) Multiple Sparking Technology ignition system. G3i compliments the synchronized firing event in all naturally aspirated and supercharged Lycoming & Continental engines. The MST amplifier discharges synchronized multiple sparks, which lasts for 20° of crankshaft rotation. The G3i system operates by switching the magnetos from their typical normal state to the more versatile electronic MST ignition.” Postaccident examination of the airplane revealed that, with the airplane’s electrical power and magneto systems on and the G3i system off, the engine’s ignition system functioned normally. When the G3i system was turned on, the magneto system did not function. The 7.5-amp fuse installed for the MSD unit was blown. The G3i Installation Manual stated “NOTE: In flight loss of engine power or suspected G3i ignition system failure, Toggle off the power to the G3i ignition system to revert back to default magneto mode.” According to the Federal Aviation Administration Aviation Safety Inspector who conducted the postaccident examination of the airplane, the pilot was unaware of the G3i Installation Manual note since no aircraft build records were provided to him as the buyer of the airplane. The pilot stated to the National Transportation Safety Board Investigator-in-Charge that he did not toggle off the G3i system because he did not have time to diagnose the cause of the engine power loss. The pilot said that he did not have an engine-out checklist. There was no G3i flight manual supplement/placard for emergency procedures relating to the failure of the G3i system, and such a supplement/placard was not required. The pilot of the experimental, amateur-built airplane stated that the airplane sustained a total loss of engine power during the departure climb. The pilot then performed a forced landing on a field near the departure end of the runway. During the landing, the airplane’s landing gear dug into soft terrain resulting in a nose over of the airplane. The airplane sustained substantial damage to both wings. Postaccident examination revealed the airplane was equipped with a supplemental ignition system. Two units of the supplemental system were installed with fuses that were not called for in the system installation instructions. One of the fuses was blown, which disabled one of the two units and did not allow for the airplane’s magneto system to continue providing engine ignition, resulting in a total loss of engine power. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

Hierarchical cause / factor breakdown from the FAA bulk avdata database. Each finding tagged C (Cause) or F (Factor).

• — Aircraft-Aircraft power plant-Ignition system-Ignition power supply-Incorrect service/maintenance
• — Aircraft-Aircraft power plant-Ignition system-Ignition power supply-Failure
• — Personnel issues-Task performance-Maintenance-Installation-Other