The crash position indicator (CPI) is a radio beacon designed to be ejected from an aircraft when it crashes. This helps ensure it survives the crash and any post-crash fires or sinking, allowing it to broadcast a homing signal to search and rescue aircraft.
CPI's became a requirement on some military aircraft and were often combined with flight data recorders. Today the beacon functions are normally fulfilled by the emergency locator transmitter system. The term "crash position indicator" no longer refers to the specific device, but any locator beacon. The CPI is ranked No. 48 in the list of the 50 Greatest Canadian Inventions.
