Amateur-built Hyster N7167S accident near Lake Jackson, Texas

Probable cause

The improper maintenance of the throttle control cable, which resulted in the engine going to idle power after takeoff.

NTSB analysis

The experimental airplane recently had a new engine and propeller installed, and an associate of the owner was going to test fly the airplane after the installation. Shortly after takeoff, the engine went to idle and the pilot was forced to land. While maneuvering toward an open field, the airplane collided with a power line, bounced hard on the ground, and flipped inverted. Postaccident examination of the engine and carburetor revealed that the set screw that held the throttle cable to the carburetor was loose. The cable could be moved freely by hand through the carburetor arm with no restriction. The cable showed no evidence that it had been scored or pulled when the engine separated during the accident. No marks were found where the set screw should have been tightened in place on the cable. In addition, when the cable was inserted back into the carburetor arm, it took one full turn of the set screw to make contact and secure the cable in place. The condition and lack of security of the throttle cable most likely resulted in a reduced fuel flow to the carburetor and the subsequent partial loss of engine power. Usable fuel was present in the airplane and no other malfunctions or failures with the airframe or engine were found that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for CEN11LA671 for the full record.