Norman Dean Piepenbrink

Sergeant Norman Piepenbrink was killed in a helicopter accident while working as an observer with Pilot Willard J. Lehmanon. The officers were conducting freeway traffic patrol in a Bell 47J helicopter. Sergeant Piepenbrink, the officer-in-charge of the Air Support Division, departed and another officer who was piloting the helicopter had departed from the Los Angeles County Sheriff's Department helipad at the Biscailuz Center in East Los Angeles. Immediately after departure, the aircrew overheard three loud, distinct thumps. The helicopter subsequently crashed, badly burning Sergeant Piepenbrink and the pilot. An investigation revealed that the six rotor driving flange screws in the main rotor transmission had failed. This failure allowed the transmission rotor driving flange to become uncoupled from the transmission upper spider, causing a complete loss of engine torque to the main rotor. The six screws fractured from a static shear overload, resulting in a forced landing on unsuitable terrain. The aircraft was destroyed. Sergeant Piepenbrink succumbed to his injuries three days later. Despite being badly burned, the pilot survived the crash. Sergeant Piepenbrink was a U.S Army veteran of WWII and had served with the Los Angeles Police Department for 18 years.