19980417016099A

(.4)While at cruise altitude, the pilot said he noticed a burning smell after he had operated the experimental airplane's auxiliary fuel pump. He said he did not notice any changes in the engine indications. He said, 'approximately 1-minute later I noticed the reduction in engine power... .' He said he decided to make a precautionary landing on a road. When the pilot reduced the engine's power setting, the engine experienced a total loss of power. The pilot said the airplane '...built up excessive speed...' During its descent. During the landing, the airplane encountered ground affect and did not touch down as the pilot had intended. While in ground affect the airplane collided with a telephone pole and bridge frame before colliding with a ditch and coming to rest. The on-scene investigation revealed that the airplane's engine driven magneto experienced a drive coupling failure. The coupling had fractured into 4 pieces. One face on two of the four pieces had a surface with beach marks on them and no shear lips along their edges. These two faces matched each other. The remaining fracture surfaces had a coarse texture with shear lips along their edges. (-23) the sonerai pilot was attempting an emergency landing after the engine stopped. The aircraft struck an electrical pole, turned slightly left and impacted a bridge rail. The aircraft then slid into a ditch and overturned. The cast aluminum drive collar/coupling keyed to the flywheel and drives the magneto, cracked apart. The friction and heat fused this to a stationary cross engine mount.