Boeing 757

The Boeing 757 is an American narrow-body airliner designed and built by Boeing Commercial Airplanes. The then-named 7N7, a twinjet successor for the trijet 727, received its first orders in August 1978. The prototype completed its maiden flight on February 19, 1982, and it was FAA certified on December 21, 1982. Eastern Air Lines placed the initial 757-200 variant in commercial service on January 1, 1983. A package freighter (PF) variant entered service in September 1987 and a combi model in September 1988. The stretched 757-300 was launched in September 1996 and began service in March 1999. After 1,050 had been built for 54 customers, production ended in October 2004, while Boeing offered the largest 737 Next Generation variants as a successor to the -200.

The jetliner is powered by 36,600–43,500 lbf (163–193 kN) Rolls-Royce RB211 or Pratt & Whitney PW2000 underwing turbofan engines for a 255,000–273,000 lb (116–124 t) maximum takeoff weight (MTOW). The 757 has a 2,000 sq ft (185 m²) supercritical wing for reduced aerodynamic drag and a conventional tail. It keeps the 707 fuselage width and six–abreast seating and its two-crew glass cockpit has a common type rating with the concurrently designed 767 (a wide-body aircraft). It was produced in two fuselage lengths: the 155 ft (47.3 m) long 757-200 (the most popular with 913 built) typically seats 200 passengers in two classes over 3,915 nautical miles [nmi] (7,250 km; 4,505 mi); while the 178 ft (54.4 m) long 757-300 typically seats 243 over 3,400 nmi (6,295 km; 3,900 mi). The 757-200F can haul a 72,210 lb (32,755 kg) payload over 2,935 nmi (5,435 km; 3,378 mi). Passenger 757-200s have been modified for cargo use as the Special Freighter (SF) and the Precision Converted Freighter (PCF).

Major customers for the 757 included U.S. mainline carriers, European charter airlines, and cargo companies. It was commonly used for short and mid-range domestic routes, shuttle services, and transcontinental U.S. flights. ETOPS extended flights were approved in 1986 to fly intercontinental routes. Private and government operators have customized the 757 as VIP carriers such as the US C-32. In July 2017, there were 665 Boeing 757 in commercial service, with Delta Air Lines being the largest operator with 127 airplanes in its fleet. The airliner has recorded ten hull-loss accidents out of a total of 13 hull losses, as of August 2023^[update].

In the early 1970s, following the launch of the first wide-body airliner, the 747, Boeing began considering further developments of its narrow-body 727. Designed for short and medium length routes, the trijet was the best-selling jetliner of the 1960s and a mainstay of the U.S. domestic airline market. Studies focused on improving the 189-seat 727-200, the most successful variant. Two approaches were considered: a stretched 727 (to be designated 727-300), and an all-new aircraft code-named 7N7. The former was a cheaper derivative using the 727's existing technology and tail-mounted engine configuration, while the latter was a twin-engine aircraft which made use of new materials and improvements to propulsion technology which had become available in the civil aerospace industry.

United Airlines provided input for the proposed 727-300, which Boeing was poised to launch in late 1975, but lost interest after examining development studies for the 7N7. Although the 727-300 was offered to Braniff International Airways and other carriers, customer interest remained insufficient for further development. Instead, airlines were drawn to the high-bypass-ratio turbofan engines, new flight deck technologies, lower weight, improved aerodynamics, and reduced operating cost promised by the 7N7. These features were also included in a parallel development effort for a new mid-size wide-body airliner, code-named 7X7, which became the 767. Work on both proposals accelerated as a result of the airline industry upturn in the late 1970s.

By 1978, development studies focused on two variants: a 7N7-100 with seating for 160, and a 7N7-200 with room for over 180 seats. New features included a redesigned wing, under-wing engines, and lighter materials, while the forward fuselage, cockpit layout, and T-tail configuration were retained from the 727. Boeing planned for the aircraft to offer the lowest fuel burn per passenger-kilometer of any narrow-body airliner. On August 31, 1978, Eastern Air Lines and British Airways became the first carriers to publicly commit to the 7N7 when they announced launch orders totaling 40 aircraft for the 7N7-200 version. These orders were signed in March 1979, when Boeing officially designated the aircraft as the 757. The shorter 757-100 did not receive any orders and was dropped; 737s later fulfilled its envisioned role.

The 757 was intended to be more capable and more efficient than the preceding 727. The focus on fuel efficiency reflected airline concerns over operating costs, which had grown amid rising oil prices during the Yom Kippur War of 1973. Design targets included a 20 percent reduction in fuel consumption from new engines, plus 10 percent from aerodynamic improvements, versus preceding aircraft. Lighter materials and new wings were also expected to improve efficiency. The maximum take-off weight (MTOW) was set at 220,000 pounds (99,800 kg), which was 10,000 pounds (4,540 kg) more than the 727. The 757's higher thrust-to-weight ratio allowed it to take off from short runways and serve airports in hot and high conditions with higher ambient temperatures and thinner air, offering better takeoff performance than that offered by competing aircraft. Competitors needed longer takeoff runs for these hot and high conditions. Boeing also offered options for higher payload capability.

The twin-engine configuration was chosen for greater fuel efficiency versus three- and four-engine designs. Launch customers Eastern Air Lines and British Airways selected the RB211-535C turbofan built by Rolls-Royce, which was capable of 37,400 pounds-force (166 kN) of thrust. This marked the first time that a Boeing airliner was launched with engines produced outside the U.S. Domestic manufacturer Pratt & Whitney subsequently offered the 38,200 pounds-force (170 kN) thrust PW2037, which Delta Air Lines launched with an order for 60 aircraft in November 1980. General Electric also offered its CF6-32 engine early in the program, but eventually abandoned its involvement due to insufficient demand.