Boeing 757-200SF

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 727 (a trijet), 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 original 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 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 NG variants as a successor.

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 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 long 757-200 (the most popular with 913 built) typically seats 200 passengers in two classes over 3,915 nmi / 7,250 km; while the long 757-300 typically seats 243 over 3,400 nmi (6,295 km).
The 757-200F can haul a 72,210 lb (32,755 kg) payload over 2,935 nmi (5,435 km).
Passenger 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 twelve hull-loss accidents, including eight fatal crashes, .

Development

Background

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 , 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 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 with seating for 160, and a 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 version. These orders were signed in March 1979, when Boeing officially designated the aircraft as the 757. The shorter did not receive any orders and was dropped; 737s later fulfilled its envisioned role.

Design effort

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 , which was 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.Ostrower, Jon, and Wall, Robert, "Boeing weighs options to reprise aging 757s", ''Wall Street Journal'', February 11, 2015, pp. B1–2.

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 turbofan built by Rolls-Royce, which was capable of 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 thrust PW2037, which Delta Air Lines launched with an order for 60 aircraft in November 1980. General Electric also offered its engine early in the program, but eventually abandoned its involvement due to insufficient demand.

As development progressed, the 757 increasingly departed from its 727 origins and adopted elements from the 767, which was several months ahead in development. To reduce risk and cost, Boeing combined design work on both twinjets, resulting in shared features such as interior fittings and handling characteristics. Computer-aided design, first applied on the 767, was used for over one-third of the 757's design drawings. In early 1979, a common two-crew member glass cockpit was adopted for the two aircraft, including shared instrumentation, avionics, and flight management systems. In October 1979 the nose was widened and dropped to reduce aerodynamic noise by six dB, to improve the flight deck view and to give more working area for the crew for greater commonality with the 767. Cathode-ray tube (CRT) color displays replaced conventional electromechanical instruments, with increased automation eliminating the flight engineer position common to three-person cockpits. After completing a short conversion course, pilots rated on the 757 could be qualified to fly the 767 and vice versa, owing to their design similarities.

A new aft-loaded shape which produced lift across most of the upper wing surface, instead of a narrow band as in previous airfoil designs, was used for the 757's wings. The more efficient wings had less drag and greater fuel capacity, and were similar in configuration to those on the 767. A wider wingspan than the 727's produced less lift-induced drag, while larger wing roots increased undercarriage storage space and provided room for future stretched versions of the aircraft.

One of the last 727 vestiges, the T-tail, was dropped in mid-1979 in favor of a conventional tail. This avoided the risk of an aerodynamic condition known as a deep stall, and allowed for more passengers to be carried in a less tapered rear fuselage. At in length, the was longer than the , and with a greater proportion of its internal volume devoted to cabin space, seating was available for 239 passengers, or 50 more than its predecessor. The fuselage cross-section, whose upper lobe was common to the 707 and 737, was the only major structural feature to be retained from the 727. This was mainly to reduce drag, and while a wider fuselage had been considered, Boeing's market research found low cargo capacity needs and reduced passenger preference for wide-body aircraft on short-haul routes.

Production and testing

Boeing built a final assembly line in Washington at its Renton factory, home of 707, 727, and 737 production, to produce the 757. Early in the development program, Boeing, British Airways, and Rolls-Royce unsuccessfully lobbied the British aircraft industry to manufacture 757 wings. Ultimately, about half of the aircraft's components, including the wings, nose section, and empennage, were produced in-house at Boeing facilities with the remainder subcontracted to primarily U.S.-based companies. Fairchild Aircraft made the leading edge slats, Grumman supplied the flaps, and Rockwell International produced the main fuselage. Production ramp-up for the new narrow-body airliner coincided with the winding-down of the 727 program, and final assembly of the first aircraft began in January 1981.

The prototype 757 rolled out of the Renton factory on January 13, 1982. The aircraft, equipped with engines, completed its maiden flight one week ahead of schedule on February 19, 1982. The first flight was affected by an engine stall, following indications of low oil pressure. After checking system diagnostics, company test pilot John Armstrong and co-pilot Lew Wallick were able to restart the affected engine, and the flight proceeded normally thereafter. Subsequently, the 757 embarked on a seven-day weekly flight test schedule. By this time, the aircraft had received 136 orders from seven carriers, namely Air Florida, American Airlines, British Airways, Delta Air Lines, Eastern Air Lines, Monarch Airlines, and Transbrasil.

The seven-month 757 flight test program used the first five aircraft built. Tasks included flight systems and propulsion tests, hot and cold weather trials, and route-proving flights. Data from the 767 program helped expedite the process. After design issues were identified, the 757's exit doors received dual-spring mechanisms for easier operation, and the fuselage was strengthened for greater bird strike resistance. The production aircraft was lighter than originally specified, and recorded a three percent better-than-expected rate of fuel burn. This resulted in a range increase of , and prompted Boeing to tout the aircraft's fuel efficiency characteristics. After 1,380 flight test hours, the RB211-powered 757 received U.S. Federal Aviation Administration (FAA) certification on December 21, 1982, followed by UK Civil Aviation Authority (CAA) certification on January 14, 1983. The first delivery to launch customer Eastern Air Lines occurred on December 22, 1982, about four months after the first 767 deliveries. The first 757 with PW2037 engines rolled out about one year later, and was delivered to Delta Air Lines on November 5, 1984.

Service entry and operations

Eastern Air Lines operated the first commercial 757 flight on January 1, 1983, on the Atlanta-to-Tampa route. On February 9, 1983, British Airways began using the aircraft for London-to-Belfast shuttle services, where it replaced Hawker Siddeley Trident 3B trijets. Charter carriers Monarch Airlines and Air Europe also began 757 operations later that year. Early operators noted improved reliability and quieter performance compared with previous jetliners. Transition courses eased pilots' introduction to the new CRT-based cockpit, and no major technical issues arose. Eastern Air Lines, the first 727 operator to take delivery of 757s, confirmed that the aircraft had greater payload capability than its predecessor, along with lower operating costs through improved fuel burn and the use of a two-crew member flight deck. Compared with the 707 and 727, the new twinjet consumed 42 and 40 percent less fuel per seat, respectively, on typical medium-haul flights.

Despite the successful debut, 757 sales remained stagnant for most of the 1980s, a consequence of declining fuel prices and a shift to smaller aircraft in the post-deregulation U.S. market. Although no direct competitor existed, 150-seat narrow-bodies such as the McDonnell Douglas MD-80 were less expensive and carried nearly as many passengers as some airlines' 757s. A three-year sales drought abated in November 1983 when Northwest Airlines placed orders for 20 aircraft, which averted a costly production rate decrease. In December 1985, a freighter model, the , was announced following a launch order for 20 aircraft from UPS Airlines, and in February 1986, a freighter-passenger combi model, the , was launched with an order for one aircraft from Royal Nepal Airlines. The freighter model included a main deck cargo hold and entered service with UPS in September 1987. The combi model could carry both cargo and passengers on its main deck and entered service with Royal Nepal Airlines in September 1988.

In the late 1980s, increasing airline hub congestion and the onset of U.S. airport noise regulations fueled a turnaround in 757 sales. From 1988 to 1989, airlines placed 322 orders, including a combined 160 orders from American Airlines and United Airlines. By this time, the 757 had become commonplace on short-haul domestic flights and transcontinental services in the U.S., and had replaced aging 707s, 727s, Douglas DC-8s, and McDonnell Douglas DC-9s. The maximum range of , which was over one-and-a-half times the 727's, allowed airlines to use the aircraft on longer nonstop routes. The 757 was also flown out of airports with stringent noise regulations, such as John Wayne Airport in Orange County, California, and airports with aircraft size restrictions, such as Washington National Airport near downtown Washington, D.C. The largest U.S. operators, Delta Air Lines and American Airlines, would ultimately operate fleets of over 100 aircraft each.

In Europe, British Airways, Iberia, and Icelandair were the 757's largest mainline customers, while other carriers such as Lufthansa rejected the type as too large for their narrow-body aircraft needs. Many European charter airlines, including Air 2000, Air Holland, and LTU International, also acquired the twinjet for holiday and tour package flights in the late 1980s. In Asia, where even larger aircraft were commonly preferred because of greater passenger volumes, the 757 found fewer orders. A 1982 sales demonstration was unable to attract a purchase from potential customer Japan Airlines, and the first Asian customer, Singapore Airlines, sold its four 757s in 1989 in favor of standardizing on the 240-seat wide-body Airbus A310, just five years after debuting the type on Indonesian and Malaysian routes. The 757 fared better in China, where following an initial purchase by the CAAC Airlines in 1987, orders grew to 59 aircraft, making it the largest Asian market. Operators such as China Southern, China Southwest, Shanghai Airlines, Xiamen Airlines, and Xinjiang Airlines

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