The P-3 Orion was introduced to the fleet in the early 1960s. It is a derivative of the Lockheed Electra commercial airliner, which was not designed for survivability. More than 40 years later, it remains the Navy’s sole land-based multi-mission aircraft. Several studies were conducted by the Naval Weapons Center at China Lake in the 1980s to assess the survivability needs of the P-3. Those studies concluded that numerous enhancements were needed, including a missile warning system, a countermeasures dispenser, a radio-frequency (RF) jammer of some type, fuel tank protection, dry bay fire suppression, and flight control system hardening. The P-3’s infrared (IR) signature was in need of reduction, and an IR missile seeker jammer was required. Since its introduction, the P-3 has undergone a series of configuration changes to include several updates, the most recent of which addressed survivability with enhancements to the missile warning system, countermeasures dispensing system, and explosive suppressant foam to prevent fuel tank explosions.