Amateur-built RV14 N14NP accident near Orchard, Texas

Probable cause

The failure of an alternator belt and the builder/previous owner’s incorrect electrical wiring of the airplane’s other alternator, which resulted in a total loss of electrical and engine power.

NTSB analysis

About 10 minutes into the accident flight, the pilot noticed the left and right battery indications on the instrument panel turned on and off several times. About 8 minutes later, he noticed a loss of electrical power to the secondary electronic flight instrument system (EFIS) and several other avionics, but the primary EFIS was still powered, and the engine continued to operate normally. The pilot turned back toward the departure airport and flew for another 10 minutes until the airplane lost all electrical and engine power. The pilot then made a forced landing to a field, which resulted in substantial damage to the airplane.

Recorded flight data provided by the pilot indicated that the airplane’s EFIS generated a battery alert shortly before takeoff; intermittent battery alerts continued for about 17 minutes. However, the NTSB was unable to verify the accuracy of these data.

Postaccident examinations revealed that the No. 2 alternator belt had failed; the No. 1 alternator belt remained intact. The airplane’s two batteries did not show any voltage when tested with a multimeter. Due to incorrect electrical wiring, only the No. 2 alternator charged the batteries while the airplane was operating.

The No. 2 alternator belt likely failed in flight, after which the engine and some avionics were able to operate for a short time using battery power. Because the airplane was equipped with an electronic ignition and fuel injection system, the engine lost power when the batteries subsequently discharged and were unable to produce adequate voltage.

Text from the NTSB. Open the NTSB docket for CEN23LA402 for the full record.