Lockheed L-188 Electra II

The Lockheed L-188 Electra is an American turboprop airliner built by Lockheed. First flown in 1957, it was the first large turboprop airliner built in the United States. Initial sales were good, but after two fatal crashes that led to expensive modifications to fix a design defect, no more were ordered. With its unique high power-to-weight ratio, huge propellers and very short wings (resulting in the majority of the wingspan being enveloped in propwash), large Fowler flaps which significantly increased effective wing area when extended, and four-engined design, the airplane had airfield performance capabilities unmatched by many jet transport aircraft even today—particularly on short runways and high field elevations.[citation needed] Jet airliners soon supplanted turboprops for many purposes, and many Electras were modified as freighters. Some Electras are still being used in various roles into the 21st century. The airframe was also used as the basis for the Lockheed P-3 Orion maritime patrol aircraft.

Lockheed P-3 Orion

The Lockheed P-3 Orion is a four-engined, 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 anomaly detection (MAD) of submarines.

Over the years, the aircraft has seen numerous design developments, most notably in its electronics packages. Numerous navies and air forces around the world continue to use the P-3 Orion, primarily for maritime patrol, reconnaissance, anti-surface warfare and anti-submarine warfare.[1] A total of 757 P-3s have been built and, in 2012, it joined the handful of military aircraft including the Boeing B-52 Stratofortress, Boeing KC-135 Stratotanker, Lockheed C-130 Hercules and the Lockheed U-2 that the United States military has been using for more than 50 years. The Boeing P-8 Poseidon will eventually replace the U.S. Navy's remaining P-3C aircraft.