Lockheed L-188 Electra
Aircraft Description
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. With its fairly 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 altitude airfields. Initial sales were good, but after two fatal crashes that led to expensive modifications to fix a design defect, no more were ordered. 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.[1][3] The airframe was also used as the basis for the Lockheed P-3 Orion maritime patrol aircraft.
The Model 188 Electra is a low-wing cantilever monoplane powered by four wing-mounted Allison 501-D13 turboprops. It has a retractable tricycle landing gear and a conventional tail. It has a cockpit crew of three and can carry 66 to 80 passengers in a mixed-class arrangement, although 98 could be carried in a high-density layout. The first variant was the Model 188A, followed by the longer-range 188C with room for 1,000 US gallons (3,800 L) more fuel and maximum take-off weight 15000 KG / 33069 lbs.
American Airlines was the launch customer. Eastern Air Lines, Braniff Airways, and Northwest Airlines followed. The Electra suffered a troubled start. Passengers of early aircraft complained of noise in the cabin forward of the wings, caused by propeller resonance.[8] Lockheed redesigned the engine nacelles, tilting the engines upwards 3°.[8][9] The changes were incorporated on the production line by mid-1959 or as modification kits for the aircraft already built, and resulted in improved performance and a better ride for passengers.
