The Lockheed AP-3C Orion is a variant of the P-3 Orion used by the Royal Australian Air Force (RAAF) for tasks such as naval fleet support, maritime surveillance, search and survivor supply and anti-surface and anti-submarine warfare. The 18 AP-3C Orions were upgraded from P-3Cs between 1997 and 2005, with the program taking three years longer than expected due to systems integration problems. All 18 AP-3C Orions are operated by No.