RUTAN VARIEZE — Columbia, CA

What happened

The pilot had been performing maintenance on the airplane and upgrading various systems. The accident flight was the first flight out of maintenance.

According to radar and ADS-B data, the airplane departed and the pilot executed several maneuvers before returning to the runway. The airplane then made a high-speed pass over the airport, reversed course, and approached the runway again. After a second high-speed pass over the runway, the airplane joined the traffic pattern for landing. As the airplane turned on final approach it was about 680 ft above ground level (agl) at an airspeed of about 70 knots. Over the next 24 seconds, it descended toward terrain at an airspeed of about 66 knots, coming to rest about 0.5 nautical miles (nm) from the runway.

A comparison of the airplane’s two approach paths revealed similar speeds and altitudes until the final approach., where the accident flight ADS-B data ends abruptly. At the last ADS-B return, the airplane would have been around 200 ft agl and there was a well-traveled road beneath the flight path.

Postaccident examinations revealed no definitive evidence of a failure with the flight control systems. The engine exhibited no evidence of preimpact catastrophic mechanical malfunction or failure, but the negligible damage to the propeller suggests that the engine was not operating at the time of impact. The close proximity of the accident site to the runway’s surface, additionally suggests that the airplane did not have adequate power to reach the runway.

The exact fuel quantity at impact could not be determined due to the airplane’s position at the accident site, though there was likely sufficient fuel.

During recent maintenance, the pilot modified the airplane to a dual-ignition system, replacing one of the magnetos with an electronic ignition system. The remaining magneto was improperly wired to the ignition, rendering it inoperable unless the keyed-ignition switch was set to the “BOTH” position. This would have made it impossible for the pilot to verify that both ignition systems were operable during the runup unless the electronic switch was activated and was operable, which could not be definitively determined. Disassembly of the magneto revealed fine carbon dust and a worn distributor brush, which could have impaired its performance.

The ignition key was found removed from the switch, which was in the OFF position, while the master switch was in the ON position. This suggests that the pilot was likely troubleshooting the ignition system before impact, as it is unlikely he would remove the key without turning off the master switch during an engine-out procedure.

The electronic ignition system wiring had two separations where the splices were not properly crimped, allowing the wires to come loose. It is unclear if these separations occurred during the impact. The electronic ignition switch was also found broken internally, with one disconnected wire, and therefore it is unknown if the electronic switch was ever operable. The wiring at the front of the airplane was stretched and hanging over a boulder, making it difficult to determine the damage to the wiring before impact.

If the electronic ignition wiring or switch had not been intact on the flight, the engine would have been operating solely on the magneto. If the pilot then turned the keyed ignition switch to the LEFT or RIGHT position, the magneto would have shut off, resulting in a total loss of power.

An editorial "what led to it / how to avoid it" analysis for this accident is generated separately and will appear here.