Amateur-built Glasair III N1YZ accident near Reno, Nevada

Probable cause

The excessively worn throttle/mixture linkage arms and pins and a missing mixture control linkage spring washer, which resulted in a loss of power due to an excessively rich mixture.

NTSB analysis

The pilot reported that as he turned toward the airport to land, black smoke was coming from under the cowling. The airplane was losing power, airspeed, and altitude; however, he was able to maintain enough airspeed to clear a cliff before touching down short of the runway. The airplane encountered uneven terrain, and the landing gear sheared off. An inspection of the engine revealed that all spark plugs and the entire exhaust path were very sooty, which corresponded to rich operation. Examination of the fuel servo revealed that it had excessively worn throttle/mixture linkage arms and pins. In addition, the mixture control linkage spring washer was missing. This linkage section is vital to maintaining the correct flows at throttle open positions, and the play noted was excessive.

Text from the NTSB. Open the NTSB docket for LAX08LA268 for the full record.