Amateur-built RV10 N878TD accident near Fort Worth, Texas

Probable cause

A partial loss of engine power due to a separated electronic ignition system connector. Contributing to the accident was the location of the ignition boxes, which provided limited access to the connectors for visual inspection.

NTSB analysis

The pilot reported that, during the initial climb following a touch-and-go landing, the engine backfired and lost partial power about 200 ft above ground level. The airplane descended and collided with a power line before impact with terrain and a tree, resulting in substantial damage.

The airplane engine was equipped with an electronic ignition system and automotive-style sparkplugs.

The ignition system was field-tested by passing a magnet over the flywheel ignition sensor; spark was observed only on one bank of the ignition system. The ignition leads and coil labels did not necessarily correspond to the associated cylinder, and the ignition firing order was not confirmed.

The ignition control boxes were located behind the firewall, and the fuselage was cut open to allow access to the boxes. The output cable on ignition box #1 was found disconnected and the pin connectors were not fully secured. The boxes could only be accessed from under the instrument panel and by reaching above the rudder pedals.

The accident is consistent with a partial loss of engine power due to the disconnection of the #1 ignition box, likely as a result of not being fully secured. It is likely that the location of the ignition boxes, which limited access and visual inspection of the connections, contributed to the accident.

Text from the NTSB. Open the NTSB docket for CEN21LA273 for the full record.