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Boeing 767

The Boeing 767 is an American wide-body airliner developed and manufactured by Boeing Commercial Airplanes.

The aircraft was launched as the 7X7 program on July 14, 1978, the prototype first flew on September 26, 1981, and it was certified on July 30, 1982. The initial 767-200 variant entered service on September 8, 1982, with United Airlines, and the extended-range 767-200ER in 1984. It was stretched into the 767-300 in October 1986, followed by the extended-range 767-300ER in 1988, the most popular variant. The 767-300F, a production freighter version, debuted in October 1995. It was stretched again into the 767-400ER from September 2000.

Designed to complement the larger 747, it has a seven-abreast cross-section accommodating smaller LD2 ULD cargo containers. The 767 is Boeing's first wide-body twinjet, powered by General Electric CF6, Rolls-Royce RB211, or Pratt & Whitney JT9D turbofans. JT9D engines were eventually replaced by PW4000 engines. The aircraft has a conventional tail and a supercritical wing for reduced aerodynamic drag. Its two-crew glass cockpit, a first for a Boeing airliner, was developed jointly for the 757 − a narrow-body aircraft, allowing a common pilot type rating. Studies for a higher-capacity 767 in 1986 led Boeing to develop the larger 777 twinjet, introduced in June 1995.

The 48.5 m 767-200 typically seats 216 passengers over 3,900 nautical miles [nmi] (7,200 km; 3900 nmi), while the 767-200ER seats 181 over a 6,590 nmi (12,200 km; 6590 nmi) range. The 54.9 m 767-300 typically seats 269 passengers over 3,900 nmi (7,200 km; 3900 nmi), while the 767-300ER seats 218 over 5,980 nmi (11,070 km; 5980 nmi). The 767-300F can haul 52.7 t over 3,225 nmi (6,025 km; 3225 nmi), and the 61.37 m 767-400ER typically seats 245 passengers over 5,625 nmi (10,415 km; 5625 nmi). Military derivatives include the E-767 for surveillance and the KC-767 and KC-46 aerial tankers.

Initially marketed for transcontinental routes, a loosening of ETOPS rules starting in 1985 allowed the aircraft to operate transatlantic flights. A total of 742 of these aircraft were in service in July 2018, with Delta Air Lines being the largest operator with 77 aircraft in its fleet.

, Boeing has received 1,407 orders from 74 customers, of which 1,312 airplanes have been delivered, while the remaining orders are for cargo or tanker variants. Competitors have included the Airbus A300, A310, and A330-200. Its successor, the 787 Dreamliner, entered service in 2011.

Background
In 1970, the 747 entered service as the first wide-body jetliner with a fuselage wide enough to feature a twin-aisle cabin. Two years later, the manufacturer began a development study, code-named 7X7, for a new wide-body jetliner intended to replace the 707 and other early generation narrow-body airliners. The aircraft would also provide twin-aisle seating, but in a smaller fuselage than the existing 747, McDonnell Douglas DC-10, and Lockheed L-1011 TriStar wide-bodies. To defray the high cost of development, Boeing signed risk-sharing agreements with Italian corporation Aeritalia and the Civil Transport Development Corporation (CTDC), a consortium of Japanese aerospace companies. This marked the manufacturer's first major international joint venture, and both Aeritalia and the CTDC received supply contracts in return for their early participation. The initial 7X7 was conceived as a short take-off and landing airliner intended for short-distance flights, but customers were unenthusiastic about the concept, leading to its redefinition as a mid-size, transcontinental-range airliner. At this stage the proposed aircraft featured two or three engines, with possible configurations including over-wing engines and a T-tail.

By 1976, a twinjet layout, similar to the one which had debuted on the Airbus A300, became the baseline configuration. The decision to use two engines reflected increased industry confidence in the reliability and economics of new-generation jet powerplants. While airline requirements for new wide-body aircraft remained ambiguous, the 7X7 was generally focused on mid-size, high-density markets. As such, it was intended to transport large numbers of passengers between major cities. Advancements in civil aerospace technology, including high-bypass-ratio turbofan engines, new flight deck systems, aerodynamic improvements, and more efficient lightweight designs were to be applied to the 7X7. Many of these features were also included in a parallel development effort for a new mid-size narrow-body airliner, code-named 7N7, which would become the 757. Work on both proposals proceeded through the airline industry upturn in the late 1970s.

In January 1978, Boeing announced a major extension of its Everett factory—which was then dedicated to manufacturing the 747—to accommodate its new wide-body family. In February 1978, the new jetliner received the 767 model designation, and three variants were planned: a 767-100 with 190 seats, a 767-200 with 210 seats, and a trijet 767MR/LR version with 200 seats intended for intercontinental routes. The 767MR/LR was subsequently renamed 777 for differentiation purposes. The 767 was officially launched on July 14, 1978, when United Airlines ordered 30 of the 767-200 variant, followed by 50 more 767-200 orders from American Airlines and Delta Air Lines later that year. The 767-100 was ultimately not offered for sale, as its capacity was too close to the 757's seating, while the 777 trijet was eventually dropped in favor of standardizing the twinjet configuration.

Design effort
In the late 1970s, operating cost replaced capacity as the primary factor in airliner purchases. As a result, the 767's design process emphasized fuel efficiency from the outset. Boeing targeted a 20 to 30 percent cost saving over earlier aircraft, mainly through new engine and wing technology. As development progressed, engineers used computer-aided design for over a third of the 767's design drawings, and performed 26,000 hours of wind tunnel tests. Design work occurred concurrently with the 757 twinjet, leading Boeing to treat both as almost one program to reduce risk and cost. Both aircraft would ultimately receive shared design features, including avionics, flight management systems, instruments, and handling characteristics. Combined development costs were estimated at $3.5 to $4 billion.

Early 767 customers were given the choice of Pratt & Whitney JT9D or General Electric CF6 turbofans, marking the first time that Boeing had offered more than one engine option at the launch of a new airliner. Both jet engine models had a maximum output of 48000 lbf of thrust. The engines were mounted approximately one-third the length of the wing from the fuselage, similar to previous wide-body trijets. The larger wings were designed using an aft-loaded shape which reduced aerodynamic drag and distributed lift more evenly across their surface span than any of the manufacturer's previous aircraft. The wings provided higher-altitude cruise performance, added fuel capacity, and expansion room for future stretched variants. The initial 767-200 was designed for sufficient range to fly across North America or across the northern Atlantic, and would be capable of operating routes up to 3850 nmi.

The 767's fuselage width was set midway between that of the 707 and the 747 at 16.5 ft. While it was narrower than previous wide-body designs, seven abreast seating with two aisles could be fitted, and the reduced width produced less aerodynamic drag. The fuselage was not wide enough to accommodate two standard LD3 wide-body unit load devices side-by-side, so a smaller container, the LD2, was created specifically for the 767. Using a conventional tail design also allowed the rear fuselage to be tapered over a shorter section, providing for parallel aisles along the full length of the passenger cabin, and eliminating irregular seat rows toward the rear of the aircraft.

The 767 was the first Boeing wide-body to be designed with a two-crew digital glass cockpit. Cathode ray tube (CRT) color displays and new electronics replaced the role of the flight engineer by enabling the pilot and co-pilot to monitor aircraft systems directly. Despite the promise of reduced crew costs, United Airlines initially demanded a conventional three-person cockpit, citing concerns about the risks associated with introducing a new aircraft. The carrier maintained this position until July 1981, when a US presidential task force determined that a crew of two was safe for operating wide-body jets. A three-crew cockpit remained as an option and was fitted to the first production models. Ansett Australia ordered 767s with three-crew cockpits due to union demands; it was the only airline to operate 767s so configured. The 767's two-crew cockpit was also applied to the 757, allowing pilots to operate both aircraft after a short conversion course, and adding incentive for airlines to purchase both types.

Production and testing
To produce the 767, Boeing formed a network of subcontractors which included domestic suppliers and international contributions from Italy's Aeritalia and Japan's CTDC. The wings and cabin floor were produced in-house, while Aeritalia provided control surfaces, Boeing Vertol made the leading edge for the wings, and Boeing Wichita produced the forward fuselage. The CTDC provided multiple assemblies through its constituent companies, namely Fuji Heavy Industries (wing fairings and gear doors), Kawasaki Heavy Industries (center fuselage), and Mitsubishi Heavy Industries (rear fuselage, doors, and tail). Components were integrated during final assembly at the Everett factory. For expedited production of wing spars, the main structural member of aircraft wings, the Everett factory received robotic machinery to automate the process of drilling holes and inserting fasteners. This method of wing construction expanded on techniques developed for the 747. Final assembly of the first aircraft began in July 1979.

The prototype aircraft, registered as N767BA and equipped with JT9D turbofans, was rolled out on August 4, 1981. By this time, the 767 program had accumulated 173 firm orders from 17 customers, including Air Canada, All Nippon Airways, Britannia Airways, Transbrasil, and Trans World Airlines (TWA). On September 26, 1981, the prototype took its maiden flight under the command of company test pilots Tommy Edmonds, Lew Wallick, and John Brit. The maiden flight was largely uneventful, save for the inability to retract the landing gear because of a hydraulic fluid leak. The prototype was used for subsequent flight tests.

The 10-month 767 flight test program utilized the first six aircraft built. The first four aircraft were equipped with JT9D engines, while the fifth and sixth were fitted with CF6 engines. The test fleet was largely used to evaluate avionics, flight systems, handling, and performance, while the sixth aircraft was used for route-proving flights. During testing, pilots described the 767 as generally easy to fly, with its maneuverability unencumbered by the bulkiness associated with larger wide-body jets. Following 1,600 hours of flight tests, the JT9D-powered 767-200 received certification from the US Federal Aviation Administration (FAA) and the UK Civil Aviation Authority (CAA) in July 1982. The first delivery occurred on August 19, 1982, to United Airlines. The CF6-powered 767-200 received certification in September 1982, followed by the first delivery to Delta Air Lines on October 25, 1982.

Entry into service

The 767 entered service with United Airlines on September 8, 1982. The aircraft's first commercial flight used a JT9D-powered 767-200 on the Chicago-to-Denver route. The CF6-powered 767-200 commenced service three months later with Delta Air Lines. Upon delivery, early 767s were mainly deployed on domestic routes, including US transcontinental services. American Airlines and TWA began flying the 767-200 in late 1982, while Air Canada, China Airlines, El Al, and Pacific Western began operating the aircraft in 1983. The aircraft's introduction was relatively smooth, with few operational glitches and greater dispatch reliability than prior jetliners.

First stretch: -300/-300ER/F
Forecasting airline interest in larger-capacity models, Boeing announced the stretched 767-300 in 1983 and the extended-range 767-300ER in 1984. Both models offered a 20 percent passenger capacity increase, while the extended-range version was capable of operating flights up to 5990 nmi. Japan Airlines placed the first order for the -300 in September 1983. Following its first flight on January 30, 1986, the type entered service with Japan Airlines on October 20, 1986. The 767-300ER completed its first flight on December 9, 1986, but it was not until March 1987 that the first firm order, from American Airlines, was placed. The type entered service with American Airlines on March 3, 1988. The 767-300 and 767-300ER gained popularity after entering service, and came to account for approximately two-thirds of all 767s sold. Until the 777's 1995 debut, the 767-300 and 767-300ER remained Boeing's second-largest wide-bodies behind the 747.

Buoyed by a recovering global economy and ETOPS approval, 767 sales accelerated in the mid-to-late 1980s; 1989 was the most prolific year with 132 firm orders. By the early 1990s, the wide-body twinjet had become its manufacturer's annual best-selling aircraft, despite a slight decrease due to economic recession. During this period, the 767 became the most common airliner for transatlantic flights between North America and Europe. By the end of the decade, 767s crossed the Atlantic more frequently than all other aircraft types combined. The 767 also propelled the growth of point-to-point flights which bypassed major airline hubs in favor of direct routes. Taking advantage of the aircraft's lower operating costs and smaller capacity, operators added non-stop flights to secondary population centers, thereby eliminating the need for connecting flights. The increased number of cities receiving non-stop services caused a paradigm shift in the airline industry as point-to-point travel gained prominence at the expense of the traditional hub-and-spoke model.

In February 1990, the first 767 equipped with Rolls-Royce RB211 turbofans, a 767-300, was delivered to British Airways. Six months later, the carrier temporarily grounded its entire 767 fleet after discovering cracks in the engine pylons of several aircraft. The cracks were related to the extra weight of the RB211 engines, which are 2205 lb heavier than other 767 engines. During the grounding, interim repairs were conducted to alleviate stress on engine pylon components, and a parts redesign in 1991 prevented further cracks. Boeing also performed a structural reassessment, resulting in production changes and modifications to the engine pylons of all 767s in service.

In January 1993, following an order from UPS Airlines, Boeing launched a freighter variant, the 767-300F, which entered service with UPS on October 16, 1995. The 767-300F featured a main deck cargo hold, upgraded landing gear, and strengthened wing structure. In November 1993, the Japanese government launched the first 767 military derivative when it placed orders for the E-767, an Airborne Early Warning and Control (AWACS) variant based on the 767-200ER. The first two E-767s, featuring extensive modifications to accommodate surveillance radar and other monitoring equipment, were delivered in 1998 to the Japan Self-Defense Forces. The longest flight for the -400ER variant was completed by OMD275 of Nomadic Aviation from Bogota to Abu Dubai in the UAE on May 31, 2024.

Second stretch:-400ER
In November 1995, after abandoning development of a smaller version of the 777, Boeing announced that it was revisiting studies for a larger 767. The proposed 767-400X, a second stretch of the aircraft, offered a 12 percent capacity increase versus the 767-300, and featured an upgraded flight deck, enhanced interior, and greater wingspan. The variant was specifically aimed at Delta Air Lines' pending replacement of its aging Lockheed L-1011 TriStars, and faced competition from the A330-200, a shortened derivative of the Airbus A330. In March 1997, Delta Air Lines launched the 767-400ER when it ordered the type to replace its L-1011 fleet. In October 1997, Continental Airlines also ordered the 767-400ER to replace its McDonnell Douglas DC-10 fleet. The type completed its first flight on October 9, 1999, and entered service with Continental Airlines on September 14, 2000.

Dreamliner introduction

In the early 2000s, cumulative 767 deliveries approached 900, but new sales declined during an airline industry downturn. In 2001, Boeing dropped plans for a longer-range model, the 767-400ERX, in favor of the proposed Sonic Cruiser, a new jetliner which aimed to fly 15 percent faster while having comparable fuel costs to the 767. The following year, Boeing announced the KC-767 Tanker Transport, a second military derivative of the 767-200ER. Launched with an order in October 2002 from the Italian Air Force, the KC-767 was intended for the dual role of refueling other aircraft and carrying cargo. The Japanese government became the second customer for the type in March 2003. In May 2003, the United States Air Force (USAF) announced its intent to lease KC-767s to replace its aging KC-135 tankers. The plan was suspended in March 2004 amid a conflict of interest scandal, resulting in multiple US government investigations and the departure of several Boeing officials, including Philip Condit, the company's chief executive officer, and chief financial officer Michael Sears. The first KC-767s were delivered in 2008 to the Japan Self-Defense Forces.

In late 2002, after airlines expressed reservations about its emphasis on speed over cost reduction, Boeing halted development of the Sonic Cruiser. The following year, the manufacturer announced the 7E7, a mid-size 767 successor made from composite materials which promised to be 20 percent more fuel efficient. The new jetliner was the first stage of a replacement aircraft initiative called the Boeing Yellowstone Project. Customers embraced the 7E7, later renamed 787 Dreamliner, and within two years it had become the fastest-selling airliner in the company's history. In 2005, Boeing opted to continue 767 production despite record Dreamliner sales, citing a need to provide customers waiting for the 787 with a more readily available option. Subsequently, the 767-300ER was offered to customers affected by 787 delays, including All Nippon Airways and Japan Airlines. Some aging 767s, exceeding 20 years in age, were also kept in service past planned retirement dates due to the delays. To extend the operational lives of older aircraft, airlines increased heavy maintenance procedures, including D-check teardowns and inspections for corrosion, a recurring issue on aging 767s. The first 787s entered service with All Nippon Airways in October 2011, 42 months behind schedule.

Continued production

In 2007, the 767 received a production boost when UPS and DHL Aviation placed a combined 33 orders for the 767-300F. Renewed freighter interest led Boeing to consider enhanced versions of the 767-200 and 767-300F with increased gross weights, 767-400ER wing extensions, and 777 avionics. Net orders for the 767 declined from 24 in 2008 to just three in 2010. During the same period, operators upgraded aircraft already in service; in 2008, the first 767-300ER retrofitted with blended winglets from Aviation Partners Incorporated debuted with American Airlines. The manufacturer-sanctioned winglets, at 11 ft in height, improved fuel efficiency by an estimated 6.5 percent. Other carriers including All Nippon Airways and Delta Air Lines also ordered winglet kits.

On February 2, 2011, the 1,000th 767 rolled out, destined for All Nippon Airways. The aircraft was the 91st 767-300ER ordered by the Japanese carrier, and with its completion the 767 became the second wide-body airliner to reach the thousand-unit milestone after the 747. The 1,000th aircraft also marked the last model produced on the original 767 assembly line. Beginning with the 1,001st aircraft, production moved to another area in the Everett factory which occupied about half of the previous floor space. The new assembly line made room for 787 production and aimed to boost manufacturing efficiency by over twenty percent.

At the inauguration of its new assembly line, the 767's order backlog numbered approximately 50, only enough for production to last until 2013. Despite the reduced backlog, Boeing officials expressed optimism that additional orders would be forthcoming. On February 24, 2011, the USAF announced its selection of the KC-767 Advanced Tanker, an upgraded variant of the KC-767, for its KC-X fleet renewal program. The selection followed two rounds of tanker competition between Boeing and Airbus parent EADS, and came eight years after the USAF's original 2003 announcement of its plan to lease KC-767s. The tanker order encompassed 179 aircraft and was expected to sustain 767 production past 2013.

In December 2011, FedEx Express announced a 767-300F order for 27 aircraft to replace its DC-10 freighters, citing the USAF tanker order and Boeing's decision to continue production as contributing factors. FedEx Express agreed to buy 19 more of the −300F variant in June 2012. In June 2015, FedEx said it was accelerating retirements of planes both to reflect demand and to modernize its fleet, recording charges of $276 million (~$ in ). On July 21, 2015, FedEx announced an order for 50 767-300F with options on another 50, the largest order for the type. With the announcement FedEx confirmed that it has firm orders for 106 of the freighters for delivery between 2018 and 2023. In February 2018, UPS announced an order for 4 more 767-300Fs to increase the total on order to 63.

With its successor, the Boeing New Midsize Airplane, that was planned for introduction in 2025 or later, and the 787 being much larger, Boeing could restart a passenger 767-300ER production to bridge the gap. A demand for 50 to 60 aircraft could have to be satisfied. Having to replace its 40 767s, United Airlines requested a price quote for other widebodies. In November 2017, Boeing CEO Dennis Muilenburg cited interest beyond military and freighter uses. However, in early 2018 Boeing Commercial Airplanes VP of marketing Randy Tinseth stated that the company did not intend to resume production of the passenger variant.

In its first quarter of 2018 earnings report, Boeing plans to increase its production from 2.5 to 3 monthly beginning in January 2020 due to increased demand in the cargo market, as FedEx had 56 on order, UPS has four, and an unidentified customer has three on order. This rate could rise to 3.5 per month in July 2020 and 4 per month in January 2021, before decreasing to 3 per month in January 2025 and then 2 per month in July 2025. In 2019, unit cost was US$217.9 million for a -300ER, and US$220.3 million for a -300F.

Production of the 767 was expected to cease by the end of 2027 due to more stringent emissions and noise limits that will go into effect in 2028. However,, the US Congress is considering giving Boeing a waiver to continue to produce the 767 freighter for an additional five years. If granted, these aircraft would be restricted to domestic use within the US only. Boeing is widely expected to begin production of 787 Freighter during that extension period.

767-X (partial double-deck)
After the debut of the first stretched 767s, Boeing sought to address airline requests for greater capacity by proposing larger models, including a partial double-deck version informally named the "Hunchback of Mukilteo" (from a town near Boeing's Everett factory) with a 757 body section mounted over the aft main fuselage. In 1986, Boeing proposed the 767-X, a revised model with extended wings and a wider cabin, but received little interest. The 767-X did not get enough interest from airlines to launch and the model was shelved in 1988 in favor of the Boeing 777.

767-400ERX
In March 2000, Boeing was to launch the 259-seat 767-400ERX with an initial order for three from Kenya Airways with deliveries planned for 2004, as it was proposed to Lauda Air. Increased gross weight and a tailplane fuel tank would have boosted its range by 11100 to 12025 km, and GE could offer its 65000-68000 lbf CF6-80C2/G2. Rolls-Royce offered its 68,000-72,000 lbf Trent 600 for the 767-400ERX and the Boeing 747X.

Offered in July, the longer-range -400ERX would have a strengthened wing, fuselage and landing gear for a 15,000 lb (6.8 t) higher MTOW, up to 465,000 lb (210.92 t). Thrust would rise to 72,000 lbf for better takeoff performance, with the Trent 600 or the General Electric/Pratt & Whitney Engine Alliance GP7172, also offered on the 747X. Range would increase by 525 nmi (950 km; 525 nmi) to 6,150 nmi (11,390 km; 6150 nmi), with an additional fuel tank of 2,145 U.S. gallons (8,120 L) in the horizontal tail. The 767-400ERX would offer the capacity of the Airbus A330-200 with 3% lower fuel burn and costs. Boeing cancelled the variant development in 2001. Kenya Airways then switched its order to the 777-200ER.

767-XF (re-engine)
In October 2019, Boeing was reportedly studying a re-engined 767-XF for entry into service around 2025, based on the 767-400ER with an extended landing gear to accommodate larger General Electric GEnx turbofan engines. The cargo market is the main target, but a passenger version could be a cheaper alternative to the proposed New Midsize Airplane.

Overview

The 767 is a low-wing cantilever monoplane with a conventional tail unit featuring a single fin and rudder. The wings are swept at 31.5 degrees and optimized for a cruising speed of Mach 0.8 (533 mph). Each wing features a supercritical airfoil cross-section and is equipped with six-panel leading edge slats, single- and double-slotted flaps, inboard and outboard ailerons, and six spoilers. The airframe further incorporates Carbon-fiber-reinforced polymer composite material wing surfaces, Kevlar fairings and access panels, plus improved aluminum alloys, which together reduce overall weight by 1900 lb versus preceding aircraft.

To distribute the aircraft's weight on the ground, the 767 has a retractable tricycle landing gear with four wheels on each main gear and two for the nose gear. The original wing and gear design accommodated the stretched 767-300 without major changes. The 767-400ER features a larger, more widely spaced main gear with 777 wheels, tires, and brakes. To prevent damage if the tail section contacts the runway surface during takeoff, 767-300 and 767-400ER models are fitted with a retractable tailskid.

All passenger 767 models have exit doors near the front and rear of the aircraft. Most 767-200 and -200ER models have one overwing exit door for emergency use; an optional second overwing exit increases maximum allowable capacity from 255 to 290. The 767-300 and -300ER typically feature two overwing exit doors or, in a configuration with no overwing exits, three exit doors on each side and a smaller exit door aft of the wing. A further configuration featuring three exit doors on each side plus one overwing exit allows an increase in maximum capacity from 290 to 351. All 767-400ERs are configured with three exit doors on each side and a smaller exit door aft of the wing. The 767-300F has one exit door at the forward left-hand side of the aircraft.

In addition to shared avionics and computer technology, the 767 uses the same auxiliary power unit, electric power systems, and hydraulic parts as the 757. A raised cockpit floor and the same forward cockpit windows result in similar pilot viewing angles. Related design and functionality allows 767 pilots to obtain a common type rating to operate the 757 and share the same seniority roster with pilots of either aircraft.

Flight systems

The original 767 flight deck uses six Rockwell Collins CRT screens to display electronic flight instrument system (EFIS) and engine indication and crew alerting system (EICAS) information, allowing pilots to handle monitoring tasks previously performed by the flight engineer. The CRTs replace conventional electromechanical instruments found on earlier aircraft. An enhanced flight management system, improved over versions used on early 747s, automates navigation and other functions, while an automatic landing system facilitates CAT IIIb instrument landings in low visibility situations. The 767 became the first aircraft to receive CAT IIIb certification from the FAA for landings with 980 ft minimum visibility in 1984. On the 767-400ER, the cockpit layout is simplified further with six Rockwell Collins liquid crystal display (LCD) screens, and adapted for similarities with the 777 and the Next Generation 737. To retain operational commonality, the LCD screens can be programmed to display information in the same manner as earlier 767s. In 2012, Boeing and Rockwell Collins launched a further 787-based cockpit upgrade for the 767, featuring three landscape-format LCD screens that can display two windows each.

The 767 is equipped with three redundant hydraulic systems for operation of control surfaces, landing gear, and utility actuation systems. Each engine powers a separate hydraulic system, and the third system uses electric pumps. A ram air turbine provides power for basic controls in the event of an emergency. An early form of fly-by-wire is employed for spoiler operation, utilizing electric signaling instead of traditional control cables. The fly-by-wire system reduces weight and allows independent operation of individual spoilers.

Interior
The 767 features a twin-aisle cabin with a typical configuration of six abreast in business class and seven across in economy. The standard seven abreast, 2–3–2 economy class layout places approximately 87 percent of all seats at a window or aisle. As a result, the aircraft can be largely occupied before center seats need to be filled, and each passenger is no more than one seat from the aisle. It is possible to configure the aircraft with extra seats for up to an eight abreast configuration, but this is less common.

The 767 interior introduced larger overhead bins and more lavatories per passenger than previous aircraft. The bins are wider to accommodate garment bags without folding, and strengthened for heavier carry-on items. A single, large galley is installed near the aft doors, allowing for more efficient meal service and simpler ground resupply. Passenger and service doors are an overhead plug type, which retract upwards, and commonly used doors can be equipped with an electric-assist system.

In 2000, a 777-style interior, known as the Boeing Signature Interior, debuted on the 767-400ER. Subsequently, adopted for all new-build 767s, the Signature Interior features even larger overhead bins, indirect lighting, and sculpted, curved panels. The 767-400ER also received larger windows derived from the 777. Older 767s can be retrofitted with the Signature Interior. Some operators have adopted a simpler modification known as the Enhanced Interior, featuring curved ceiling panels and indirect lighting with minimal modification of cabin architecture, as well as aftermarket modifications such as the NuLook 767 package by Heath Tecna.

Operational history

In its first year, the 767 logged a 96.1 percent dispatch rate, which exceeded the industry average for all-new aircraft. Operators reported generally favorable ratings for the twinjet's sound levels, interior comfort, and economic performance. Resolved issues were minor and included the recalibration of a leading edge sensor to prevent false readings, the replacement of an evacuation slide latch, and the repair of a tailplane pivot to match production specifications.

Seeking to capitalize on its new wide-body's potential for growth, Boeing offered an extended-range model, the 767-200ER, in its first year of service. Ethiopian Airlines placed the first order for the type in December 1982. Featuring increased gross weight and greater fuel capacity, the extended-range model could carry heavier payloads at distances up to 6385 nmi, and was targeted at overseas customers. The 767-200ER entered service with El Al Airline on March 27, 1984. The type was mainly ordered by international airlines operating medium-traffic, long-distance flights. In May 1984, an Ethiopian Airlines 767-200ER set a non-stop record for a commercial twinjet of 12,082 km from Washington, D.C. to Addis Ababa.

In the mid-1980s, the 767 and its European rivals, the Airbus A300 and A310, spearheaded the growth of twinjet flights across the northern Atlantic under extended-range twin-engine operational performance standards (ETOPS) regulations, the FAA's safety rules governing transoceanic flights by aircraft with two engines. In 1976, the A300 was the first twinjet to secure permission to fly 90 minutes away from diversion airports, up from 60 minutes. In May 1985, the FAA granted its first approval for 120-minute ETOPS flights to the 767, on an individual airline basis starting with TWA, provided that the operator met flight safety criteria. This allowed the aircraft to fly overseas routes at up to two hours' distance from land. The 767 burned 7,000 lb less fuel per hour than a Lockheed L-1011 TriStar on the route between Boston and Paris, a huge savings. The Airbus A310 secured approval for 120-minute ETOPS flights one month later in June. The larger safety margins were permitted because of the improved reliability demonstrated by twinjets and their turbofan engines. The FAA lengthened the ETOPS time to 180 minutes for CF6-powered 767s in 1989, making the type the first to be certified under the longer duration, and all available engines received approval by 1993. Regulatory approval spurred the expansion of transoceanic flights with twinjet aircraft and boosted the sales of both the 767 and its rivals.

Variants

The 767 has been produced in three fuselage lengths. These debuted in progressively larger form as the 767-200, 767-300, and 767-400ER. Longer-range variants include the 767-200ER and 767-300ER, while cargo models include the 767-300F, a production freighter, and conversions of passenger 767-200 and 767-300 models.

When referring to different variants, Boeing and airlines often collapse the model number (767) and the variant designator, e.g. –200 or –300, into a truncated form, e.g. "762" or "763". Subsequent to the capacity number, designations may append the range identifier, though -200ER and -300ER are company marketing designations and not certificated as such. The International Civil Aviation Organization (ICAO) aircraft type designator system uses a similar numbering scheme, but adds a preceding manufacturer letter; all variants based on the 767-200 and 767-300 are classified under the codes "B762" and "B763"; the 767-400ER receives the designation of "B764".

767-200
The 767-200 was the original model and entered service with United Airlines in 1982. The type has been used primarily by mainline U.S. carriers for domestic routes between major hub centers such as Los Angeles to Washington. The 767-200 was the first aircraft to be used on transatlantic ETOPS flights, beginning with TWA on February 1, 1985, under 90-minute diversion rules. Deliveries for the variant totaled 128 aircraft. There were 52 examples of the model in commercial service, almost entirely as freighter conversions. The type's competitors included the Airbus A300 and A310.

The 767-200 was produced until 1987 when production switched to the extended-range 767-200ER. Some early 767-200s were subsequently upgraded to extended-range specification. In 1998, Boeing began offering 767-200 conversions to 767-200SF (Special Freighter) specification for cargo use, and Israel Aerospace Industries has been licensed to perform cargo conversions since 2005. The conversion process entails the installation of a side cargo door, strengthened main deck floor, and added freight monitoring and safety equipment. The 767-200SF was positioned as a replacement for Douglas DC-8 freighters.

767-2C
A commercial freighter version of the Boeing 767-200 with wings from the -300 series and an updated flightdeck was first flown on December 29, 2014. A military tanker variant of the Boeing 767-2C is developed for the USAF as the KC-46. Boeing is building two aircraft as commercial freighters which will be used to obtain Federal Aviation Administration certification, a further two Boeing 767-2Cs will be modified as military tankers. , Boeing does not have customers for the freighter.

767-200ER

The 767-200ER was the first extended-range model and entered service with El Al in 1984. The type's increased range is due to extra fuel capacity and higher maximum takeoff weight (MTOW) of up to 395000 lb. The additional fuel capacity is accomplished by using the center tank's dry dock to carry fuel. The non-ER variant's center tank is what is called cheek tanks; two interconnected halves in each wing root with a dry dock in between. The center tank is also used on the -300ER and -400ER variants.

This version was originally offered with the same engines as the 767-200, while more powerful Pratt & Whitney PW4000 and General Electric CF6 engines later became available. The 767-200ER was the first 767 to complete a non-stop transatlantic journey, and broke the flying distance record for a twinjet airliner on April 17, 1988, with an Air Mauritius flight from Halifax, Nova Scotia to Port Louis, Mauritius, covering 8727 nmi. The 767-200ER has been acquired by international operators seeking smaller wide-body aircraft for long-haul routes such as New York to Beijing. Deliveries of the type totaled 121 with no unfilled orders. As of July 2018, 21 examples of passenger and freighter conversion versions were in airline service. The type's main competitors of the time included the Airbus A300-600R and the A310-300.

767-300
The 767-300, the first stretched version of the aircraft, entered service with Japan Airlines in 1986. The type features a 21.1 ft fuselage extension over the 767-200, achieved by additional sections inserted before and after the wings, for an overall length of 180.25 ft. Reflecting the growth potential built into the original 767 design, the wings, engines, and most systems were largely unchanged on the 767-300. An optional mid-cabin exit door is positioned ahead of the wings on the left, while more powerful Pratt & Whitney PW4000 and Rolls-Royce RB211 engines later became available. The 767-300's increased capacity has been used on high-density routes within Asia and Europe. The 767-300 was produced from 1986 until 2000. Deliveries for the type totaled 104 aircraft with no unfilled orders remaining. The type's main competitor was the Airbus A300.

767-300ER

The 767-300ER, the extended-range version of the 767-300, entered service with American Airlines in 1988. The type's increased range was made possible by greater fuel tankage and a higher MTOW of 407000 lb. Design improvements allowed the available MTOW to increase to 412000 lb by 1993. Power is provided by Pratt & Whitney PW4000, General Electric CF6, or Rolls-Royce RB211 engines. The 767-300ER comes in three exit configurations: the baseline configuration has four main cabin doors and four over-wing window exits, the second configuration has six main cabin doors and two over-wing window exits; and the third configuration has six main cabin doors, as well as two smaller doors that are located behind the wings. Typical routes for the type include New York to Frankfurt.

The combination of increased capacity and range for the -300ER has been particularly attractive to both new and existing 767 operators. It is the most successful 767 version, with more orders placed than all other variants combined. , 767-300ER deliveries stand at 583 with no unfilled orders. There were 376 examples in service. The type's main competitor is the Airbus A330-200. At its 1990s peak, a new 767-300ER was valued at $85 million, dipping to around $12 million in 2018 for a 1996 build.

767-300F

The 767-300F, the production freighter version of the 767-300ER, entered service with UPS Airlines in 1995. The 767-300F can hold up to 24 standard 88 by pallets on its main deck and up to 30 LD2 unit load devices on the lower deck, with a total cargo volume of 15469 cuft. The freighter has a main deck cargo door and crew exit, while the lower deck features two starboard-side cargo doors and one port-side cargo door. A general market version with onboard freight-handling systems, refrigeration capability, and crew facilities was delivered to Asiana Airlines on August 23, 1996. , 767-300F deliveries stand at 161 with 61 unfilled orders. Airlines operated 222 examples of the freighter variant and freighter conversions in July 2018.

Converted freighters
In June 2008, All Nippon Airways took delivery of the first 767-300BCF (Boeing Converted Freighter), a modified passenger-to-freighter model. The conversion work was performed in Singapore by ST Aerospace Services, the first supplier to offer a 767-300BCF program, and involved the addition of a main deck cargo door, strengthened main deck floor, and additional freight monitoring and safety equipment.

Israel Aerospace Industries offers a passenger-to-freighter conversion program called the 767-300BDSF (BEDEK Special Freighter). Wagner Aeronautical also offers a passenger-to-freighter conversion program for 767-300 series aircraft.

767-400ER

The 767-400ER, the first Boeing wide-body jet resulting from two fuselage stretches, entered service with Continental Airlines in 2000. The type features a 21.1 ft stretch over the 767-300, for a total length of 205.11 ft. The wingspan is also increased by 14.3 ft through the addition of raked wingtips. The exit configuration uses six main cabin doors and two smaller exit doors behind the wings, similar to certain 767-300ERs. Other differences include an updated cockpit, redesigned landing gear, and 777-style Signature Interior. Power is provided by uprated General Electric CF6 engines.

The FAA granted approval for the 767-400ER to operate 180-minute ETOPS flights before it entered service. Because its fuel capacity was not increased over preceding models, the 767-400ER has a range of 5625 nmi, less than previous extended-range 767s. No 767-400 (non-extended range) version was developed.

The longer-range 767-400ERX was offered in July 2000 before being cancelled a year later, leaving the 767-400ER as the sole version of the largest 767. Boeing dropped the 767-400ER and the -200ER from its pricing list in 2014.

A total of 37 767-400ERs were delivered to the variant's two airline customers, Continental Airlines (now merged with United Airlines as of 2010) and Delta Air Lines, with no unfilled orders. All 37 examples of the -400ER were in service in July 2018. One additional example was produced as a military testbed for cancelled E-10, and later sold to Bahrain as a VIP transport. The type's closest competitor is the Airbus A330-200.

Military and government
Versions of the 767 serve in a number of military and government applications, with responsibilities ranging from airborne surveillance and refueling to cargo and VIP transport. Several military 767s have been derived from the 767-200ER, the longest-range version of the aircraft.
 * Airborne Surveillance Testbed – the Airborne Optical Adjunct (AOA) was modified from the prototype 767-200 for a United States Army program, under a contract signed with the Strategic Air Command in July 1984. Intended to evaluate the feasibility of using airborne optical sensors to detect and track hostile intercontinental ballistic missiles, the modified aircraft first flew on August 21, 1987. Alterations included a large "cupola" or hump on the top of the aircraft from above the cockpit to just behind the trailing edge of the wings, and a pair of ventral fins below the rear fuselage. Inside the cupola was a suite of infrared seekers used for tracking theater ballistic missile launches. The aircraft was later renamed as the Airborne Surveillance Testbed (AST). Following the end of the AST program in 2002, the aircraft was retired for scrapping.

 * E-767 – the Airborne Early Warning and Control (AWACS) platform for the Japan Self-Defense Forces; it is essentially the Boeing E-3 Sentry mission package on a 767-200ER platform. E-767 modifications, completed on 767-200ERs flown from the Everett factory to Boeing Integrated Defense Systems in Wichita, Kansas, include strengthening to accommodate a dorsal surveillance radar system, engine nacelle alterations, as well as electrical and interior changes. Japan operates four E-767s. The first E-767s were delivered in March 1998.

 * KC-767 Tanker Transport – the 767-200ER-based aerial refueling platform operated by the Italian Air Force (Aeronautica Militare), and the Japan Self-Defense Forces. Modifications conducted by Boeing Integrated Defense Systems include the addition of a fly-by-wire refueling boom, strengthened flaps, and optional auxiliary fuel tanks, as well as structural reinforcement and modified avionics. The four KC-767Js ordered by Japan have been delivered. The Aeronautica Militare received the first of its four KC-767As in January 2011.
 * KC-767 Advanced Tanker – the 767-200ER-based aerial tanker developed for the USAF KC-X tanker competition. It is an updated version of the KC-767, originally selected as the USAF's new tanker aircraft in 2003, designated KC-767A, and then dropped amid conflict of interest allegations. The KC-767 Advanced Tanker is derived from studies for a longer-range cargo version of the 767-200ER, and features a fly-by-wire refueling boom, a remote vision refueling system, and a 767-400ER-based flight deck with LCD screens and head-up displays.
 * KC-46 - a 767-based tanker, not derived from the KC-767, awarded as part of the KC-X contract for the USAF.
 * Tanker conversions – the 767 MMTT or Multi-Mission Tanker Transport is a 767-200ER-based aircraft operated by the Colombian Air Force (Fuerza Aérea Colombiana) and modified by Israel Aerospace Industries. In 2013, the Brazilian Air Force ordered two 767-300ER tanker conversions from IAI for its KC-X2 program.
 * E-10 MC2A - the Northrop Grumman E-10 was to be a 767-400ER-based replacement for the USAF's 707-based E-3 Sentry AWACS, Northrop Grumman E-8 Joint STARS, and RC-135 SIGINT aircraft. The E-10 would have included an all-new AWACS system, with a powerful active electronically scanned array (AESA) that was also capable of jamming enemy aircraft or missiles. One 767-400ER aircraft was built as a testbed for systems integration, but the program was terminated in January 2009 and the prototype was later sold to Bahrain as a VIP transport.

Operators
In July 2018, 742 aircraft were in airline service: 73 -200s, 632 -300, and 37 -400ER with 65 -300F on order; the largest operators are Delta Air Lines (77), FedEx (60; largest cargo operator), UPS Airlines (59), United Airlines, Japan Airlines (35), All Nippon Airways (34).

The largest 767 customers by orders placed are FedEx Express (150), Delta Air Lines (117), All Nippon Airways (96), American Airlines (88), and United Airlines (82). Delta and United are the only customers of all -200, -300, and -400ER passenger variants. In July 2015, FedEx placed a firm order for 50 Boeing 767 freighters with deliveries from 2018 to 2023. The type's competitors included the Airbus A300 and A310.

Orders and deliveries
Boeing 767 orders and deliveries (cumulative, by year):

 * Data.

Model summary

 * Data.

Accidents and incidents

, the Boeing 767 has been in 67 aviation occurrences, including 19 hull-loss accidents. Seven fatal crashes, including three hijackings, have resulted in a total of 854 occupant fatalities.

Accidents
The airliner's first fatal crash, Lauda Air Flight 004, occurred near Bangkok on May 26, 1991, following the in-flight deployment of the left engine thrust reverser on a 767-300ER. None of the 223 aboard survived. As a result of this accident, all 767 thrust reversers were deactivated until a redesign was implemented. Investigators determined that an electronically controlled valve, common to late-model Boeing aircraft, was to blame. A new locking device was installed on all affected jetliners, including 767s.

On October 31, 1999, EgyptAir Flight 990, a 767-300ER, crashed off Nantucket, Massachusetts, in international waters killing all 217 people on board. The United States National Transportation Safety Board (NTSB) concluded "not determined", but determined the probable cause to be a deliberate action by the first officer; Egypt disputed this conclusion.

On April 15, 2002, Air China Flight 129, a 767-200ER, crashed into a hill amid inclement weather while trying to land at Gimhae International Airport in Busan, South Korea. The crash resulted in the death of 129 of the 166 people on board, and the cause was attributed to pilot error.

On February 23, 2019, Atlas Air Flight 3591, a Boeing 767-300ERF air freighter operating for Amazon Air, crashed into Trinity Bay near Houston, Texas, while on descent into George Bush Intercontinental Airport; both pilots and the single passenger were killed. The cause was attributed to pilot error and spatial disorientation.

On November 1, 2011, LOT Polish Airlines Flight 16, a 767-300ER, safely landed at Warsaw Chopin Airport in Warsaw, Poland, after a mechanical failure of the landing gear forced an emergency landing with the landing gear retracted. There were no injuries, but the aircraft involved was damaged and subsequently written off. At the time of the incident, aviation analysts speculated that it may have been the first instance of a complete landing gear failure in the 767's service history. Subsequent investigation determined that while a damaged hose had disabled the aircraft's primary landing gear extension system, an otherwise functional backup system was inoperative due to an accidentally deactivated circuit breaker.
 * Hull losses

On October 28, 2016, American Airlines Flight 383, a 767-300ER with 161 passengers and 9 crew members, aborted takeoff at Chicago O'Hare Airport following an uncontained failure of the right GE CF6-80C2 engine. The engine failure, which hurled fragments over a considerable distance, caused a fuel leak, resulting in a fire under the right wing. Fire and smoke entered the cabin. All passengers and crew evacuated the aircraft, with 20 passengers and one flight attendant sustaining minor injuries using the evacuation slides.

The 767 has been involved in six hijackings, three resulting in loss of life, for a combined total of 282 occupant fatalities. On November 23, 1996, Ethiopian Airlines Flight 961, a 767-200ER, was hijacked and crash-landed in the Indian Ocean near the Comoro Islands after running out of fuel, killing 125 out of the 175 persons on board; this was a rare example of occupants surviving a land-based aircraft ditching on water. Two 767s were involved in the September 11 attacks on the World Trade Center in 2001, resulting in the collapse of its two main towers. American Airlines Flight 11, a 767-200ER, crashed into the North Tower, killing all 92 people on board, and United Airlines Flight 175, a 767-200, crashed into the South Tower, with the death of all 65 on board. In addition, more than 2,600 people were killed in the towers or on the ground. A failed 2001 shoe bomb attempt that December involved an American Airlines 767-300ER.
 * Hijackings

Incidents
The 767's first incident was Air Canada Flight 143, a 767-200, on July 23, 1983. The airplane ran out of fuel at an altitude of about 41,000 feet. Eventually, the pilots had to glide with both engines out for almost 43 nmi to an emergency landing at Gimli, Manitoba, Canada. The pilots used the aircraft's ram air turbine to power the hydraulic systems for aerodynamic control. There were no fatalities and only minor injuries. This aircraft was nicknamed "Gimli Glider" after its landing site. The aircraft, registered C-GAUN, continued flying for Air Canada until its retirement in January 2008.

In January 2014, the U.S. Federal Aviation Administration issued a directive that ordered inspections of the elevators on more than 400 767s beginning in March 2014; the focus was on fasteners and other parts that can fail and cause the elevators to jam. The issue was first identified in 2000 and has been the subject of several Boeing service bulletins. The inspections and repairs are required to be completed within six years. The aircraft has also had multiple occurrences of "uncommanded escape slide inflation" during maintenance or operations, and during flight. In late 2015, the FAA issued a preliminary directive to address the issue.

Aircraft on display

As new 767 variants roll off the assembly line, older series models have been retired and converted to cargo use, stored, or scrapped. One complete aircraft, N102DA, is the first 767-200 to operate for Delta Air Lines and the twelfth example built. It was retired from airline service in February 2006 after being repainted back to its original 1982 Delta widget livery and given a farewell tour. It was then put on display at the Delta Flight Museum in the Delta corporate campus at the edge of Hartsfield–Jackson Atlanta International Airport. "The Spirit of Delta" is on public display as of 2022.

In 2013 a Brazilian entrepreneur purchased a 767-200 that had operated for the now-defunct carrier Transbrasil under the registration PT-TAC. The aircraft, which was sold at a bankruptcy auction, was placed on outdoor display in Taguatinga as part of a proposed commercial development. , however, the development has not come to fruition. The aircraft is devoid of engines or landing gear and has deteriorated due to weather exposure and acts of vandalism but remains publicly accessible to view.

Specifications
Below is an organized chart composed of the variants of the 767 and their specifications.

title: Boeing 767


text:
Bill Walsh (American football coach)

William Ernest Walsh (November 30, 1931 – July 30, 2007) was an American professional and college football coach. He served as head coach of the San Francisco 49ers and the Stanford Cardinal, during which time he popularized the West Coast offense. After retiring from the 49ers, Walsh worked as a sports broadcaster for several years and then returned as head coach at Stanford for three seasons.

Walsh went 102–63–1 (wins-losses-ties) with the 49ers, winning 10 of his 14 postseason games along with six division titles, three NFC Championship titles, and three Super Bowls. He was named NFL Coach of the Year in 1981 and 1984. In 1993, he was elected to the Pro Football Hall of Fame. He is widely considered amongst the greatest coaches in NFL history.

Early life
Walsh was born in Los Angeles. He attended Hayward High School in Hayward in the San Francisco Bay Area, where he played running back. Walsh played quarterback at the College of San Mateo for two seasons. (Both John Madden and Walsh played and coached at the College of San Mateo early in their careers.) After playing at the College of San Mateo, Walsh transferred to San José State University, where he played tight end and defensive end. He also participated in intercollegiate boxing, winning the golden glove.

Walsh graduated from San Jose State with a bachelor's degree in physical education in 1955. After two years in the U.S. Army participating on their boxing team, Walsh built a championship team at Washington High School in Fremont before becoming an assistant coach at Cal, Stanford and then the Oakland Raiders in 1966.

College coaching career
He served under Bob Bronzan as a graduate assistant coach on the Spartans football coaching staff and graduated with a master's degree in physical education from San Jose State in 1959. His master's thesis was entitled Flank Formation Football -- Stress: Defense. Thesis 796.W228f.

Following graduation, Walsh coached the football and swim teams at Washington High School in Fremont, California. While there he interviewed for an assistant coaching position with the new head coach of the University of California, Berkeley California Golden Bears football team, Marv Levy.

"I was very impressed, individually, by his knowledge, by his intelligence, by his personality, and hired him," Levy said. Levy and Walsh, two future NFL Hall of Famers, would never produce a winning season for the Golden Bears.

Leaving Berkeley, Walsh did a stint at Stanford University as an assistant coach of its Cardinal football team before beginning his pro coaching career.

Early years
Walsh began his pro coaching career in 1966 as an assistant with the AFL's Oakland Raiders. There he was versed in the downfield-oriented "vertical" passing offense favored by Al Davis, an acolyte of Sid Gillman.

Walsh left the Raiders the next year to become the head coach and general manager of the San Jose Apaches of the Continental Football League (CFL). He led the Apaches to second place in the Pacific Division, but the team ceased all football operations prior to the start of the 1968 CFL season.

In 1968, Walsh joined the staff of head coach Paul Brown of the AFL expansion Cincinnati Bengals, where he coached wide receivers from 1968 to 1970. It was there that Walsh developed the philosophy now known as the "West Coast offense". Cincinnati's new quarterback, Virgil Carter, was known for his great mobility and accuracy but lacked a strong arm necessary to throw deep passes. To suit his strengths, Walsh suggested a modification of the downfield based "vertical passing scheme" he had learned during his time with the Raiders with one featuring a "horizontal" approach that relied on quick, short throws, often spreading the ball across the entire width of the field. In 1971 Walsh was given the additional responsibility of coaching the quarterbacks, and Carter went on to lead the league in pass completion percentage.

Ken Anderson eventually replaced Carter as starting quarterback, and, together with star wide receiver Isaac Curtis, produced a consistent, effective offensive attack.

When Brown retired as head coach following the 1975 season and appointed Bill "Tiger" Johnson as his successor, Walsh resigned and served as an assistant coach in 1976 for the San Diego Chargers under head coach Tommy Prothro. In a 2006 interview, Walsh claimed that during his tenure with the Bengals, Brown "worked against my candidacy" to be a head coach anywhere in the league. "All the way through I had opportunities, and I never knew about them", Walsh said. "And then when I left him, he called whoever he thought was necessary to keep me out of the NFL." Walsh also claimed that Brown kept talking him down any time Brown was called by NFL teams considering hiring Walsh as a head coach.

In 1977, Walsh was hired by Stanford University as the head coach of its Cardinal football team, where he stayed for two seasons. He was quite successful, with his teams posting a 9–3 record in 1977 with a win in the Sun Bowl, and going 8–4 in 1978 with a win in the Bluebonnet Bowl. His notable players at Stanford included quarterbacks Guy Benjamin, Steve Dils, wide receivers James Lofton and Ken Margerum, linebacker Gordy Ceresino, and running back Darrin Nelson. Walsh was the Pac-8 Conference Coach of the Year in 1977.

49ers head coach
On January 9, 1979, Walsh resigned as head coach at Stanford, and San Francisco 49ers team owner Edward J. DeBartolo, Jr. fired head coach Fred O'Connor and general manager Joe Thomas following a 2–14 in 1978 season. Walsh was appointed head coach of the 49ers the next day.

The 49ers went 2-14 again in 1979. Hidden behind that record were organizational changes made by Walsh that set the team on a better course, including selecting Notre Dame quarterback Joe Montana in the third round of the 1979 NFL Draft.

In 1980, starting quarterback Steve DeBerg got the 49ers off to a 3–0 start, but after a week 6 blowout loss to the Dallas Cowboys by a score of 59–14, Walsh gave Montana a chance to start. On December 7 vs. the New Orleans Saints, the second-year player brought the 49ers back from a 35–7 halftime deficit to a 38–35 overtime win. In spite of this switch, the team struggled to a 6–10 finish – a record that belied a championship team in the making.

1981 championship
In 1981, Walsh's efforts as head coach led the team to a 13–3 regular season. Key victories were two wins each over the Los Angeles Rams and the Dallas Cowboys. The Rams were only two seasons removed from a Super Bowl appearance, and had dominated the series with the 49ers since 1967, winning 23, losing 3 and tying 1. San Francisco's two wins over the Rams in 1981 marked the shift of dominance in favor of the 49ers that lasted until 1998 with 30 wins (including 17 consecutively) against only 6 defeats. The 49ers blew out the Cowboys in week 6 of the regular season. On Monday Night Football that week, the win was not included in the halftime highlights. Walsh felt that this was because the Cowboys were scheduled to play the Rams the next week in a Sunday night game and that showing the highlights of the 49ers' win would potentially hurt the game's ratings. However, Walsh used this as a motivating factor for his team, who felt they were disrespected.

The 49ers faced the Cowboys again in the NFC title game. The contest was very close, and in the fourth quarter Walsh called a series of running plays as the 49ers marched down the field against the Cowboys' prevent defense, which had been expecting the 49ers to mainly pass. The 49ers came from behind to win the game on Joe Montana's pass completion to Dwight Clark for a touchdown, a play that came to be known simply as The Catch, propelling Walsh to his first appearance in a Super Bowl. Walsh would later write that the 49ers' two wins over the Rams showed a shift of power in their division, while the wins over the Cowboys showed a shift of power in the conference.

Two weeks later, on January 24, 1982, San Francisco faced the Cincinnati Bengals in Super Bowl XVI, winning 26–21 for the team's first NFL championship. Only a year removed from back-to-back two-win seasons, the 49ers had risen from the cellar to the top of the NFL in just two seasons. What came to be known as the West Coast offense developed by Walsh had proven a winner.

In all, Walsh served as 49ers head coach for 10 years, winning three Super Bowl championships, in the 1981, 1984, and 1988 seasons, and establishing a new NFL record.

Walsh had a disciplined approach to game-planning, famously scripting the first 10–15 offensive plays before the start of each game. His innovative play calling and design earned him the nickname "The Genius". In the ten-year span under Walsh, San Francisco scored 3,714 points (24.4 per game), the most of any team in the league.

In addition to Joe Montana, Walsh drafted Ronnie Lott, Charles Haley, and Jerry Rice, each one going on to the Pro Football Hall of Fame. He also traded a 2nd and 4th round pick in the 1987 draft for Steve Young, who took over from Montana, led the team to Super Bowl success, and was enshrined in Canton after his playing career. Walsh's success at every level of football, especially with the 49ers, earned him his own ticket to Canton in 1993.

On January 22, 1989, Walsh coached his final game with the 49ers, the memorable Super Bowl XXIII in which San Francisco beat Cincinnati 20–16. Walsh resigned as the 49ers head coach after the game. Walsh admitted years later that he immediately regretted the decision saying that he left too soon.

Upline
Walsh's upline coaching tree included working as assistant for American Football League great and Hall of Fame head coach Al Davis and NFL legend and Hall of Famer Paul Brown, and, through Davis, AFL great and Hall of Fame head coach Sid Gillman of the then AFL Los Angeles/San Diego Chargers.

Downline
Tree updated through December 9, 2015.

Many Walsh assistants went on to become head coaches,. including George Seifert, Mike Holmgren, Ray Rhodes, and Dennis Green. Seifert succeeded Walsh as 49ers head coach, and guided San Francisco to victories in Super Bowl XXIV and Super Bowl XXIX. Holmgren won a Super Bowl with the Green Bay Packers, and made 3 Super Bowl appearances as a head coach: 2 with the Packers, and another with the Seattle Seahawks. These coaches in turn have their own disciples who have used Walsh's West Coast system, such as former Denver Broncos head coach Mike Shanahan and former Houston Texans head coach Gary Kubiak. Mike Shanahan was an offensive coordinator under George Seifert and went on to win Super Bowl XXXII and Super Bowl XXXIII during his time as head coach of the Denver Broncos. Kubiak was first a quarterback coach with the 49ers, and then offensive coordinator for Shanahan with the Broncos. In 2015, he became the Broncos' head coach and led Denver to victory in Super Bowl 50. Dennis Green trained Tony Dungy, who won a Super Bowl with the Indianapolis Colts, and Brian Billick with his brother-in law and linebackers coach Mike Smith. Billick won a Super Bowl as head coach of the Baltimore Ravens.

Mike Holmgren trained many of his assistants to become head coaches, including Jon Gruden and Andy Reid. Gruden won a Super Bowl with the Tampa Bay Buccaneers. Reid served as head coach of the Philadelphia Eagles from 1999 to 2012, and guided the Eagles to multiple winning seasons and numerous playoff appearances, including 1 Super Bowl appearance. Ever since 2013, Reid has served as head coach of the Kansas City Chiefs. He was finally able to win a Super Bowl, when his Chiefs defeated the San Francisco 49ers in Super Bowl LIV, and two consecutive when his Chiefs defeated the Eagles in Super Bowl LVII and the San Francisco 49ers in Super Bowl LVIII. In addition to this, Marc Trestman, former head coach of the Chicago Bears, served as offensive coordinator under Seifert in the 90's. Gruden himself would train Mike Tomlin, who led the Pittsburgh Steelers to their sixth Super Bowl championship, and Jim Harbaugh, whose 49ers would face his brother, John Harbaugh, whom Reid himself trained, and the Baltimore Ravens at Super Bowl XLVII, which marked the Ravens' second World Championship.

Bill Walsh was viewed as a strong advocate for African-American head coaches in the NFL and NCAA. Thus, the impact of Walsh also changed the NFL into an equal opportunity for African-American coaches. Along with Ray Rhodes and Dennis Green, Tyrone Willingham became the head coach at Stanford, then later Notre Dame and Washington. One of Mike Shanahan's assistants, Karl Dorrell, went on to be the head coach at UCLA. Walsh directly helped propel Dennis Green into the NFL head coaching ranks by offering to take on the head coaching job at Stanford.

Later years
After leaving the coaching ranks immediately following his team's victory in Super Bowl XXIII, Walsh went to work as a broadcaster for NBC, teaming with Dick Enberg to form the lead broadcasting team, replacing Merlin Olsen.

During his time with NBC, rumors began to surface that Walsh would coach again in the NFL. There were at least two known instances.

First, according to a February 2015 article by Mike Florio of NBC Sports, after a 5–11 season in 1989, the Patriots fired Raymond Berry and unsuccessfully attempted to lure Walsh to Foxborough to become head coach and general manager. When that failed, New England promoted defensive coordinator Rod Rust; the team split its first two games and then lost 14 straight in 1990.

Second, late in the 1990 season, Walsh was rumored to become Tampa Bay's next head coach and general manager after the team fired Ray Perkins and promoted Richard Williamson on an interim basis. Part of the speculation was fueled by the fact that Walsh's contract with NBC, which ran for 1989 and 1990, would soon be up for renewal, to say nothing of the pressure Hugh Culverhouse faced to increase fan support and to fill the seats at Tampa Stadium. However, less than a week after Super Bowl XXV, Walsh not only declined Tampa Bay's offer, but he and NBC agreed on a contract extension. Walsh would continue in his role with NBC for 1991. Meanwhile, after unsuccessfully courting then-recently fired Eagles coach Buddy Ryan or Giants then-defensive coordinator Bill Belichick to man the sidelines for Tampa Bay in 1991, the Bucs stuck with Williamson. Under Williamson's leadership, Tampa Bay won only three games in 1991.

Walsh did return to Stanford as head coach in 1992, leading the Cardinal to a 10–3 record and a Pacific-10 Conference co-championship. Stanford finished the season with a victory over Penn State in the Blockbuster Bowl on January 1, 1993, and a #9 ranking in the final AP Poll. In 1994, after consecutive losing seasons, Walsh left Stanford and retired from coaching.

In 1996, Walsh returned to the 49ers as an administrative aide. Walsh was the vice president and general manager for the 49ers from 1999 to 2001 and was a special consultant to the team for three years afterwards.

In 2004, Walsh was appointed as special assistant to the athletic director at Stanford. In 2005, after then-athletic director Ted Leland stepped down, Walsh was named interim athletic director. He also acted as a consultant for his alma mater San Jose State University in their search for an athletic director and Head Football Coach in 2005.

Walsh was also the author of three books, a motivational speaker, and taught classes at the Stanford Graduate School of Business.

Walsh was a board member for the Lott IMPACT Trophy, which is named after Pro Football Hall of Fame defensive back Ronnie Lott, and is awarded annually to college football's Defensive IMPACT Player of the Year. Walsh served as a keynote speaker at the award's banquet.

Awards and honors

 * 1989 – Golden Plate Award of the American Academy of Achievement
 * 1993 – Pro Football Hall of Fame
 * 1998 – San Jose State Hall of Fame and the SJSU Tower Award, the highest award given by SJSU

Personal life
Bill married his college sweetheart Geri, and had 3 children; Steve, Craig and Elizabeth.

Death
Bill Walsh died of leukemia on July 30, 2007, at his home in Woodside, California.

Following Walsh's death, the playing field at the former Candlestick Park was renamed "Bill Walsh Field". Additionally, the regular San Jose State versus Stanford football game was renamed the "Bill Walsh Legacy Game".

Books

 * Bill Walsh and Glenn Dickey, Building a Champion: On Football and the Making of the 49ers. St Martin's Press, 1990. (ISBN 0-312-04969-2).
 * Bill Walsh, Brian Billick and James A. Peterson, Finding the Winning Edge. Sports Publishing, 1998. (ISBN 1-571-67172-2).
 * Bill Walsh with Steve Jamison and Craig Walsh, The Score Takes Care of Itself: My Philosophy of Leadership. Penguin Group Publishing, 2009 (ISBN 978-1-59184-266-8).

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Bill Walsh (American football coach)


text:
Utility knife

A utility knife is any type of knife used for general manual work purposes. Such knives were originally fixed-blade knives with durable cutting edges suitable for rough work such as cutting cordage, cutting/scraping hides, butchering animals, cleaning fish scales, reshaping timber, and other tasks. Craft knives are small utility knives used as precision-oriented tools for finer, more delicate tasks such as carving and papercutting.

Today, the term "utility knife" also includes small folding-, retractable- and/or replaceable-blade knives suited for use in the general workplace or in the construction industry. The latter type is sometimes generically called a Stanley knife, after a prominent brand.

There is also a utility knife for kitchen use, which is sized between a chef's knife and paring knife.

History
The fixed-blade utility knife was developed some 500,000 years ago, when human ancestors began to make stone knives. These knives were general-purpose tools, designed for cutting and shaping wooden implements, scraping hides, preparing food, and for other utilitarian purposes.

By the 19th century the fixed-blade utility knife had evolved into a steel-bladed outdoors field knife capable of butchering game, cutting wood, and preparing campfires and meals. With the invention of the backspring, pocket-size utility knives were introduced with folding blades and other folding tools designed to increase the utility of the overall design. The folding pocketknife and utility tool is typified by the Camper or Boy Scout pocketknife, the Swiss Army Knife, and by multi-tools fitted with knife blades. The development of stronger locking blade mechanisms for folding knives—as with the Spanish navaja, the Opinel, and the Buck 110 Folding Hunter—significantly increased the utility of such knives when employed for heavy-duty tasks such as preparing game or cutting through dense or tough materials.

Contemporary utility knives

The fixed or folding blade utility knife is popular for both indoor and outdoor use. One of the most popular types of workplace utility knife is the retractable or folding utility knife (also known as a Stanley knife, box cutter, or by various other names). These types of utility knives are designed as multi-purpose cutting tools for use in a variety of trades and crafts. Designed to be lightweight and easy to carry and use, utility knives are commonly used in factories, warehouses, construction projects, and other situations where a tool is routinely needed to mark cut lines, trim plastic or wood materials, or to cut tape, cord, strapping, cardboard, or other packaging material.

Names
In British, Australian and New Zealand English, along with Dutch, Danish and Austrian German, a utility knife frequently used in the construction industry is known as a Stanley knife. This name is a generic trademark named after Stanley Works, a manufacturer of such knives. In Israel and Switzerland, these knives are known as Japanese knives. In Brazil they are known as estiletes or cortadores Olfa (the latter, being another genericised trademark ). In Portugal, Panama and Canada they are also known as X-Acto (yet another genericised trademark ). In India, Russia, the Philippines, France, Iraq, Italy, Egypt, and Germany, they are simply called cutter. In the Flemish region of Belgium it is called cuttermes(je) (cutter knife). In general Spanish, they are known as cortaplumas (penknife, when it comes to folding blades); in Spain, Mexico, and Costa Rica, they are colloquially known as cutters; in Argentina and Uruguay the segmented fixed-blade knives are known as "Trinchetas". In Turkey, they are known as maket bıçağı (which literally translates as model knife).

Other names for the tool are box cutter or boxcutter, blade knife, carpet knife, pen knife, stationery knife, sheetrock knife, or drywall knife.

Design
Utility knives may use fixed, folding, or retractable or replaceable blades, and come in a wide variety of lengths and styles suited to the particular set of tasks they are designed to perform. Thus, an outdoors utility knife suited for camping or hunting might use a broad 75 to(-) fixed blade, while a utility knife designed for the construction industry might feature a replaceable utility blade for cutting packaging, cutting shingles, marking cut lines, or scraping paint.

Fixed blade utility knife

Large fixed-blade utility knives are most often employed in an outdoors context, such as fishing, camping, or hunting. Outdoor utility knives typically feature sturdy blades from 100 to(-) in length, with edge geometry designed to resist chipping and breakage.

The term "utility knife" may also refer to small fixed-blade knives used for crafts, model-making and other artisanal projects. These small knives feature light-duty blades best suited for cutting thin, lightweight materials. The small, thin blade and specialized handle permit cuts requiring a high degree of precision and control.

Workplace utility knives
The largest construction or workplace utility knives typically feature retractable and replaceable blades, and are made of either die-cast metal or molded plastic. Some use standard blades, others specialized double-ended utility blades. The user can adjust how far the blade extends from the handle, so that, for example, the knife can be used to cut the tape sealing a package without damaging the contents of the package. When the blade becomes dull, it can be quickly reversed or switched for a new one. Spare or used blades are stored in the hollow handle of some models, and can be accessed by removing a screw and opening the handle. Other models feature a quick-change mechanism that allows replacing the blade without tools, as well as a flip-out blade storage tray. The blades for this type of utility knife come in both double- and single-ended versions, and are interchangeable with many, but not all, of the later copies. Specialized blades also exist for cutting string, linoleum, and other materials.

Another style is a snap-off utility knife that contains a long, segmented blade that slides out from it. As the endmost edge becomes dull, it can be broken off the remaining blade, exposing the next section, which is sharp and ready for use. The snapping is best accomplished with a blade snapper that is often built-in, or a pair of pliers, and the break occurs at the score lines, where the metal is thinnest. When all of the individual segments are used, the knife may be thrown away, or, more often, refilled with a replacement blade. This design was introduced by Japanese manufacturer OLFA in 1956 as the world's first snap-off blade and was inspired from analyzing the sharp cutting edge produced when glass is broken and how pieces of a chocolate bar break into segments. The sharp cutting edge on these knives is not on the edge where the blade is snapped off; rather one long edge of the whole blade is sharpened, and there are scored diagonal breakoff lines at intervals down the blade. Thus each snapped-off piece is roughly a parallelogram, with each long edge being a breaking edge, and one or both of the short ends being a sharpened edge.

Another utility knife often used for cutting open boxes consists of a simple sleeve around a rectangular handle into which single-edge utility blades can be inserted. The sleeve slides up and down on the handle, holding the blade in place during use and covering the blade when not in use. The blade holder may either retract or fold into the handle, much like a folding-blade pocketknife. The blade holder is designed to expose just enough edge to cut through one layer of corrugated fibreboard, to minimize chances of damaging contents of cardboard boxes.

Use as weapon
Most utility knives are not well suited to use as offensive weapons, with the exception of some outdoor-type utility knives employing longer blades. However, even small blade type utility knives may sometimes find use as slashing weapons. The 9/11 Commission report stated passengers in cell phone calls reported knives or "box-cutters" were used as weapons (also Mace or a bomb) in hijacking airplanes in the September 11, 2001 terrorist attacks against the United States, though the exact design of the knives used is unknown. Two of the hijackers were known to have purchased Leatherman knives, which feature a 4 in slip-joint blade, which were not prohibited on U.S. flights at the time. Those knives were not found in the possessions the two hijackers left behind. Similar cutters, including paper cutters, have also been known to be used as a lethal weapon.

Small work-type utility knives have also been used to commit robbery and other crimes. In June 2004, a Japanese student was slashed to death with a segmented-type utility knife.

In the United Kingdom, the law was changed (effective 1 October 2007) to raise the age limit for purchasing knives, including utility knives, from 16 to 18, and to make it illegal to carry a utility knife in public without a good reason.

title: Utility knife


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Bronze

Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids, such as arsenic or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as strength, ductility, or machinability.

The archaeological period in which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in western Eurasia and India is conventionally dated to the mid-4th millennium BC (~3500 BC), and to the early 2nd millennium BC in China; elsewhere it gradually spread across regions. The Bronze Age was followed by the Iron Age starting about 1300 BC and reaching most of Eurasia by about 500 BC, although bronze continued to be much more widely used than it is in modern times.

Because historical artworks were often made of brasses (copper and zinc) and bronzes of different metallic compositions, modern museum and scholarly descriptions of older artworks increasingly use the generalized term "copper alloy" instead of the names of individual alloys. This is done (at least in part) to prevent database searches from failing merely because of errors or disagreements in the naming of historic copper alloys.

Etymology
The word bronze (1730–1740) is borrowed from Middle French bronze (1511), itself borrowed from Italian bronzo bell metal, brass (13th century, transcribed in Medieval Latin as bronzium) from either:

 * bróntion, back-formation from Byzantine Greek brontēsíon (βροντησίον, 11th century), perhaps from Brentḗsion (Βρεντήσιον, Brindisi), reputed for its bronze; or originally:
 * in its earliest form from Old Persian birinj, (برنج, brass, modern berenj) and piring (پرنگ) copper, from which also came Georgian brinǯi (ბრინჯი), Turkish pirinç, and Armenian brinj (բրինձ), also meaning bronze.

History

The discovery of bronze enabled people to create metal objects that were harder and more durable than previously possible. Bronze tools, weapons, armor, and building materials such as decorative tiles were harder and more durable than their stone and copper ("Chalcolithic") predecessors. Initially, bronze was made out of copper and arsenic or from naturally or artificially mixed ores of those metals, forming arsenic bronze.

The earliest known arsenic-copper-alloy artifacts come from a Yahya Culture (Period V 3800-3400 BCE) site, at Tal-i-Iblis on the Iranian plateau, and were smelted from native arsenical copper and copper-arsenides, such as algodonite and domeykite.

The earliest tin-copper-alloy artifact has been dated to c. 4650 BC, in a Vinča culture site in Pločnik (Serbia), and believed to have been smelted from a natural tin-copper ore, stannite.

Other early examples date to the late 4th millennium BC in Egypt, Susa (Iran) and some ancient sites in China, Luristan (Iran), Tepe Sialk (Iran), Mundigak (Afghanistan), and Mesopotamia (Iraq).

Tin bronze was superior to arsenic bronze in that the alloying process could be more easily controlled, and the resulting alloy was stronger and easier to cast. Also, unlike those of arsenic, metallic tin and the fumes from tin refining are not toxic.

Tin became the major non-copper ingredient of bronze in the late 3rd millennium BC. Ores of copper and the far rarer tin are not often found together (exceptions include Cornwall in the United Kingdom, one ancient site in Thailand and one in Iran), so serious bronze work has always involved trade with other regions. Tin sources and trade in ancient times had a major influence on the development of cultures. In Europe, a major source of tin was the British deposits of ore in Cornwall, which were traded as far as Phoenicia in the eastern Mediterranean. In many parts of the world, large hoards of bronze artifacts are found, suggesting that bronze also represented a store of value and an indicator of social status. In Europe, large hoards of bronze tools, typically socketed axes (illustrated above), are found, which mostly show no signs of wear. With Chinese ritual bronzes, which are documented in the inscriptions they carry and from other sources, the case is clear. These were made in enormous quantities for elite burials, and also used by the living for ritual offerings.

Transition to iron
Though bronze is generally harder than wrought iron, with Vickers hardness of 60–258 vs. 30–80, the Bronze Age gave way to the Iron Age after a serious disruption of the tin trade: the population migrations of around 1200–1100 BC reduced the shipping of tin around the Mediterranean and from Britain, limiting supplies and raising prices. As the art of working in iron improved, iron became cheaper and improved in quality. As cultures advanced from hand-wrought iron to machine-forged iron (typically made with trip hammers powered by water), blacksmiths also learned how to make steel. Steel is stronger and harder than bronze and holds a sharper edge longer. Bronze was still used during the Iron Age, and has continued in use for many purposes to the modern day.

Composition
There are many different bronze alloys, but typically modern bronze is 88% copper and 12% tin. Alpha bronze consists of the alpha solid solution of tin in copper. Alpha bronze alloys of 4–5% tin are used to make coins, springs, turbines and blades. Historical "bronzes" are highly variable in composition, as most metalworkers probably used whatever scrap was on hand; the metal of the 12th-century English Gloucester Candlestick is bronze containing a mixture of copper, zinc, tin, lead, nickel, iron, antimony, arsenic and an unusually large amount of silver – between 22.5% in the base and 5.76% in the pan below the candle. The proportions of this mixture suggest that the candlestick was made from a hoard of old coins. The 13th-century Benin Bronzes are in fact brass, and the 12th-century Romanesque Baptismal font at St Bartholomew's Church, Liège is sometimes described as bronze and sometimes as brass.

In the Bronze Age, two forms of bronze were commonly used: "classic bronze", about 10% tin, was used in casting; and "mild bronze", about 6% tin, was hammered from ingots to make sheets. Bladed weapons were mostly cast from classic bronze, while helmets and armor were hammered from mild bronze.

Modern commercial bronze (90% copper and 10% zinc) and architectural bronze (57% copper, 3% lead, 40% zinc) are more properly regarded as brass alloys because they contain zinc as the main alloying ingredient. They are commonly used in architectural applications. Plastic bronze contains a significant quantity of lead, which makes for improved plasticity, and was possibly used by the ancient Greeks in ship construction. Silicon bronze has a composition of Si: 2.80–3.80%, Mn: 0.50–1.30%, Fe: 0.80% max., Zn: 1.50% max., Pb: 0.05% max., Cu: balance. Other bronze alloys include aluminium bronze, phosphor bronze, manganese bronze, bell metal, arsenical bronze, speculum metal, bismuth bronze, and cymbal alloys.

Properties
Copper-based alloys have lower melting points than steel or iron and are more readily produced from their constituent metals. They are generally about 10 percent denser than steel, although alloys using aluminum or silicon may be slightly less dense. Bronze is a better conductor of heat and electricity than most steels. The cost of copper-base alloys is generally higher than that of steels but lower than that of nickel-base alloys.

Bronzes are typically ductile alloys, considerably less brittle than cast iron. Copper and its alloys have a huge variety of uses that reflect their versatile physical, mechanical, and chemical properties. Some common examples are the high electrical conductivity of pure copper, low-friction properties of bearing bronze (bronze that has a high lead content— 6–8%), resonant qualities of bell bronze (20% tin, 80% copper), and resistance to corrosion by seawater of several bronze alloys.

The melting point of bronze varies depending on the ratio of the alloy components and is about 950 °C. Bronze is usually nonmagnetic, but certain alloys containing iron or nickel may have magnetic properties. Typically bronze oxidizes only superficially; once a copper oxide (eventually becoming copper carbonate) layer is formed, the underlying metal is protected from further corrosion. This can be seen on statues from the Hellenistic period. If copper chlorides are formed, a corrosion-mode called "bronze disease" will eventually completely destroy it.

Uses
Bronze, or bronze-like alloys and mixtures, were used for coins over a longer period. Bronze was especially suitable for use in boat and ship fittings prior to the wide employment of stainless steel owing to its combination of toughness and resistance to salt water corrosion. Bronze is still commonly used in ship propellers and submerged bearings. In the 20th century, silicon was introduced as the primary alloying element, creating an alloy with wide application in industry and the major form used in contemporary statuary. Sculptors may prefer silicon bronze because of the ready availability of silicon bronze brazing rod, which allows color-matched repair of defects in castings. Aluminum is also used for the structural metal aluminum bronze. Bronze parts are tough and typically used for bearings, clips, electrical connectors and springs.

Bronze also has low friction against dissimilar metals, making it important for cannons prior to modern tolerancing, where iron cannonballs would otherwise stick in the barrel. It is still widely used today for springs, bearings, bushings, automobile transmission pilot bearings, and similar fittings, and is particularly common in the bearings of small electric motors. Phosphor bronze is particularly suited to precision-grade bearings and springs. It is also used in guitar and piano strings. Unlike steel, bronze struck against a hard surface will not generate sparks, so it (along with beryllium copper) is used to make hammers, mallets, wrenches and other durable tools to be used in explosive atmospheres or in the presence of flammable vapors. Bronze is used to make bronze wool for woodworking applications where steel wool would discolor oak. Phosphor bronze is used for ships' propellers, musical instruments, and electrical contacts. Bearings are often made of bronze for its friction properties. It can be impregnated with oil to make the proprietary Oilite and similar material for bearings. Aluminum bronze is hard and wear-resistant, and is used for bearings and machine tool ways. The Doehler Die Casting Co. of Toledo, Ohio were known for the production of Brastil, a high tensile corrosion resistant bronze alloy.

Architectural bronze
The Seagram Building on New York City's Park Avenue is the "iconic glass box sheathed in bronze, designed by Mies van der Rohe." The Seagram Building was the first time that an entire building was sheathed in bronze. The General Bronze Corporation fabricated 3,200,000 pounds (1,600 tons) of bronze at its plant in Garden City, New York. The Seagram Building is a 38-story, 516-foot bronze-and-topaz-tinted glass building. The building looks like a "squarish 38-story tower clad in a restrained curtain wall of metal and glass." "Bronze was selected because of its color, both before and after aging, its corrosion resistance, and its extrusion properties. It was not only the most expensive building of its time — $36 million — but it was the first building in the world with floor-to-ceiling glass walls. Mies van der Rohe achieved the crisp edges that were custom-made with specific detailing by General Bronze and "even the screws that hold in the fixed glass-plate windows were made of brass."

Sculptures
Bronze is widely used for casting bronze sculptures. Common bronze alloys have the unusual and desirable property of expanding slightly just before they set, thus filling the finest details of a mould. Then, as the bronze cools, it shrinks a little, making it easier to separate from the mould. The Assyrian king Sennacherib (704–681 BC) claims to have been the first to cast monumental bronze statues (of up to 30 tonnes) using two-part moulds instead of the lost-wax method.

Bronze statues were regarded as the highest form of sculpture in Ancient Greek art, though survivals are few, as bronze was a valuable material in short supply in the Late Antique and medieval periods. Many of the most famous Greek bronze sculptures are known through Roman copies in marble, which were more likely to survive. In India, bronze sculptures from the Kushana (Chausa hoard) and Gupta periods (Brahma from Mirpur-Khas, Akota Hoard, Sultanganj Buddha) and later periods (Hansi Hoard) have been found. Indian Hindu artisans from the period of the Chola empire in Tamil Nadu used bronze to create intricate statues via the lost-wax casting method with ornate detailing depicting the deities of Hinduism. The art form survives to this day, with many silpis, craftsmen, working in the areas of Swamimalai and Chennai.

In antiquity other cultures also produced works of high art using bronze. For example: in Africa, the bronze heads of the Kingdom of Benin; in Europe, Grecian bronzes typically of figures from Greek mythology; in east Asia, Chinese ritual bronzes of the Shang and Zhou dynasty—more often ceremonial vessels but including some figurine examples. Bronze continues into modern times as one of the materials of choice for monumental statuary.

Lamps
Tiffany Glass Studios, made famous by Louis C. Tiffany commonly referred to his product as favrile glass or "Tiffany glass," and used bronze in their artisan work for his Tiffany lamps.

Fountains and doors
The largest and most ornate bronze fountain known to be cast in the world was by the Roman Bronze Works and General Bronze Corporation in 1952. The material used for the fountain, known as statuary bronze, is a quaternary alloy made of copper, zinc, tin, and lead, and traditionally golden brown in color. This was made for the Andrew W. Mellon Memorial in Federal Triangle in Washington, DC. Another example of the massive, ornate design projects of bronze, and attributed to General Bronze/Roman Bronze Works were the massive bronze doors to the United States Supreme Court Building in Washington, DC.

Mirrors

Before it became possible to produce glass with acceptably flat surfaces, bronze was a standard material for mirrors. Bronze was used for this purpose in many parts of the world, probably based on independent discoveries. Bronze mirrors survive from the Egyptian Middle Kingdom (2040–1750 BC), and China from at least c. 550 BC. In Europe, the Etruscans were making bronze mirrors in the sixth century BC, and Greek and Roman mirrors followed the same pattern. Although other materials such as speculum metal had come into use, and Western glass mirrors had largely taken over, bronze mirrors were still being made in Japan and elsewhere in the eighteenth century, and are still made on a small scale in Kerala, India.

Musical instruments
Bronze is the preferred metal for bells in the form of a high tin bronze alloy known as bell metal, which is typically about 23% tin.

Nearly all professional cymbals are made from bronze, which gives a desirable balance of durability and timbre. Several types of bronze are used, commonly B20 bronze, which is roughly 20% tin, 80% copper, with traces of silver, or the tougher B8 bronze made from 8% tin and 92% copper. As the tin content in a bell or cymbal rises, the timbre drops.

Bronze is also used for the windings of steel and nylon strings of various stringed instruments such as the double bass, piano, harpsichord, and guitar. Bronze strings are commonly reserved on pianoforte for the lower pitch tones, as they possess a superior sustain quality to that of high-tensile steel.

Bronzes of various metallurgical properties are widely used in struck idiophones around the world, notably bells, singing bowls, gongs, cymbals, and other idiophones from Asia. Examples include Tibetan singing bowls, temple bells of many sizes and shapes, Javanese gamelan, and other bronze musical instruments. The earliest bronze archeological finds in Indonesia date from 1–2 BC, including flat plates probably suspended and struck by a wooden or bone mallet. Ancient bronze drums from Thailand and Vietnam date back 2,000 years. Bronze bells from Thailand and Cambodia date back to 3600 BC.

Some companies are now making saxophones from phosphor bronze (3.5 to 10% tin and up to 1% phosphorus content). Bell bronze/B20 is used to make the tone rings of many professional model banjos. The tone ring is a heavy (usually 3 lb) folded or arched metal ring attached to a thick wood rim, over which a skin, or most often, a plastic membrane (or head) is stretched – it is the bell bronze that gives the banjo a crisp powerful lower register and clear bell-like treble register.

Coins and medals

Bronze has also been used in coins; most "copper" coins are actually bronze, with about 4 percent tin and 1 percent zinc.

As with coins, bronze has been used in the manufacture of various types of medals for centuries, and "bronze medals" are known in contemporary times for being awarded for third place in sporting competitions and other events. The term is now often used for third place even when no actual bronze medal is awarded. The usage in part arose from the trio of gold, silver and bronze to represent the first three Ages of Man in Greek mythology: the Golden Age, when men lived among the gods; the Silver age, where youth lasted a hundred years; and the Bronze Age, the era of heroes. It was first adopted for a sports event at the 1904 Summer Olympics. At the 1896 event, silver was awarded to winners and bronze to runners-up, while at 1900 other prizes were given rather than medals.

Bronze is the normal material for the related form of the plaquette, normally a rectangular work of art with a scene in relief, for a collectors' market.

Biblical references
There are over 125 references to bronze ('nehoshet'), which appears to be the Hebrew word used for copper and any of its alloys. However, the Old Testament era Hebrews are not thought to have had the capability to manufacture zinc (needed to make brass) and so it is likely that 'nehoshet' refers to copper and its alloys with tin, now called bronze. In the King James Version, there is no use of the word 'bronze' and 'nehoshet' was translated as 'brass'. Modern translations use 'bronze'. Bronze (nehoshet) was used widely in the Tabernacle for items such as the bronze altar (Exodus Ch.27), bronze laver (Exodus Ch.30), utensils, and mirror (Exodus Ch.38). It was mentioned in the account of Moses holding up a bronze snake on a pole in Numbers Ch.21. In First Kings, it is mentioned that Hiram was very skilled in working with bronze, and he made many furnishings for Solomon's Temple including pillars, capitals, stands, wheels, bowls, and plates, some of which were highly decorative (see I Kings 7:13-47). Bronze was also widely used as battle armor and helmet, as in the battle of David and Goliath in I Samuel 17:5-6;38 (also see II Chron. 12:10).

title: Bronze