Lockheed P-3 Orion – Wikipedia

The Lockheed P-3 Orion is a four-engine turboprop anti-submarine and maritime surveillance aircraft developed for the United States Navy and introduced in the 1960s. Lockheed based it on the L-188 Electra commercial airliner. The aircraft is easily distinguished from the Electra by its distinctive tail stinger or “MAD Boom”, used for the magnetic detection of submarines.

: https://en.wikipedia.org/wiki/P-3_Orion