 Complete the following phrase:  The Portuguese Air Force received 42 Lockheed PV-2C Harpoons from 1953, which replaced the Curtiss SB2C-5 Helldiver as an anti-submarine aircraft. The Harpoons equipped squadrons 61 and 62 at the Montijo Air Base. In 1960, the Harpoons were replaced as maritime patrol and anti-submarine aircraft by Lockheed P2V-5 Neptunes. The remaining Harpoons were sent to Portuguese Angola and Mozambique, where they formed Squadron 91 operating from Luanda Air Base and Squadron 101 at Beira Air Base. The Harpoons were used on operations in the Angolan and 