[4] 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.
[14] 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.
[23] To reduce risk and cost, Boeing combined design work on both twinjets,[4][19] resulting in shared features such as interior fittings and handling characteristics.
[25] In early 1979, a common two-crew member glass cockpit was adopted for the two aircraft, including shared instrumentation, avionics, and flight management systems.
[24] 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 and for greater commonality with the 767.
[26] Cathode-ray tube (CRT) color displays replaced conventional electromechanical instruments,[24] with increased automation eliminating the flight engineer position common to three-person cockpits.
[25] 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.
[12][35] 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.
[39] 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.
[40] 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.
[50] In Europe, British Airways, Iberia, and Icelandair were the 757's largest mainline customers,[55] while other carriers such as Lufthansa rejected the type as too large for their narrow-body aircraft needs.
[60] Under ETOPS regulations, a set of safety standards governing twinjet flights over oceans and other areas without nearby suitable landing sites, airlines began using the aircraft for mid-range intercontinental routes.
[62] Investigators focused on the aircraft's aft-loaded wing design, which at certain points during takeoff or landing could produce wingtip vortices that were stronger than those emanating from larger 767s and 747s.
[63] Other tests were inconclusive, leading to debate among government agencies, and in 1994 and 1996 the FAA updated air traffic control regulations to require greater separation behind the 757 than other large-category jets.
[50] Besides meeting the needs of charter customers, a larger model would enable Boeing to match the passenger lift capabilities of the 767-200 with lower operating costs,[68] and counter longer-range versions of the 185-seat Airbus A321,[69] a new stretched variant of the A320 narrow-body airliner.
[78] The proposed derivative would have featured auxiliary fuel tanks, plus wing and landing gear upgrades from the 757-300, resulting in a higher MTOW and a potential range increase to over 5,000 nautical miles (9,260 km; 5,750 mi).
Each wing features a supercritical cross-section and is equipped with five-panel leading edge slats, single- and double-slotted flaps, an outboard aileron, and six spoilers.
[25][29] The reduced wing sweep eliminates the need for inboard ailerons, yet incurs little drag penalty on short and medium length routes, during which most of the flight is spent climbing or descending.
[104] The airframe further incorporates carbon-fiber reinforced plastic wing surfaces, Kevlar fairings and access panels, plus improved aluminum alloys, which together reduce overall weight by 2,100 pounds (950 kg).
[117] In 1998, the 757-300 debuted a redesigned interior derived from the Next Generation 737 and 777, including sculptured ceiling panels, indirect lighting, and larger overhead bins with an optional continuous handrail built into their base for the entire cabin length.
[120] In 2000, with wheeled carry-on baggage becoming more popular, Delta Air Lines began installing overhead bin extensions on their 757-200s to provide additional storage space,[121] and American Airlines did the same in 2001.
[29][129] The 757-200 was offered with a MTOW of up to 255,000 lb (116,000 kg);[28] some airlines and publications have referred to higher gross weight versions with ETOPS certification as "757-200ERs",[125][130][131] but this designation is not used by the manufacturer.
[49] Since the turn of the century, mainline U.S. carriers have increasingly deployed the type on transatlantic routes to Europe, and particularly to smaller cities where passenger volumes are insufficient for wide-body aircraft.
[137] The 757-200PF is specified with a MTOW of 255,000 lb (116,000 kg) for maximal range performance;[61][137] when fully loaded, the aircraft can fly up to 3,150 nautical miles (5,830 km; 3,620 mi).
[29][139] The main-deck cargo hold has a smooth fiberglass lining,[140] and a fixed rigid barrier with a sliding access door serves as a restraint wall next to the flight deck.
[80] The forward two entry doors and lobby area of the passenger aircraft are retained resulting in a main deck cargo capacity of 14 full sized pallets and one smaller LD3.
[49] Nepal Airlines ordered the 757-200M to fulfill a requirement for an aircraft that could carry mixed passenger and freight loads, and operate out of Tribhuvan International Airport, with its 4,400 ft (1,300 m) elevation, in the foothills of the Himalayas.
[156] All three aftermarket conversions modify the forward portion of the aircraft to provide room for up to ten cargo pallets, while leaving the remaining space to fit around 45 to 58 passenger seats.
[152] A higher MTOW of 272,500 lb (123,600 kg) is specified, while fuel capacity remains unchanged; as a result, the stretched variant offers a maximum range of 3,395 nautical miles (6,288 km; 3,907 mi).
[189] To celebrate the fleet's retirement, the airline unveiled one of its last three 757-200s in a retro style livery on October 4, 2010, matching the color scheme that it introduced the aircraft into service with in 1983.