Boeing 737-600/700

The 737-600 and -700 are the smaller members of Boeing's successful Next Generation 737-600/700/800/900 family.

Among the many changes, the Next Generation 737s feature more efficient CFM56-7B turbofans. The CFM56-7 combines the core of the CFM56-5 with the CFM56-3's low pressure compressor and a 1.55m (61in) fan. The 737's new wing has greater chord, span and wing area, while the tail surfaces are also larger. The 2.4m (8ft) high winglets first developed for the Boeing Business Jet development are now offered as an option on the 737-700 (and -800).

The new engines and wings allow the 737 to cruise at Mach 0.78 to Mach 0.80, while the larger wing allows greater fuel tankage and transcontinental USA range. Other features include a 777 style EFIS flightdeck with six flat panel LCDs which can be programmed to present information as on the 777 or as on the 737-300/400/500 series, allowing a common pilot type rating for the two 737 families.

The improved Next Generation Boeing 737 family (originally covered by the 737X designation) was launched in November 1993. The 737-700 was the first member of the new family to be developed, and is based on the 737-300, while the 737-600 is based on the 737-500.

The 737-700 rolled out on December 7 1996, was granted certification in November 1997 and entered service (with Southwest) the following month. The 737-600 was launched was launched on March 16 1996, first flew on January 22 1998 and entered service (with SAS) in September that year.

The Boeing Business Jet or BBJ (described separately) is based on the fuselage of the 737-700 with the larger 737-800's wing.

The BBJ's airframe also forms the basis for the convertible passenger/freighter variant of the 700, the 737-700QC, which has been ordered by the US Navy as the C-40A Clipper (to replace the DC-9 based C-9B). The C-40 first flew on April 17 2000. The naval aircraft can be converted to carry 121 passengers, or 3 pallets of cargo plus 70 passengers, or 8 pallets of cargo only. These aircraft are currently (2002) based at Naval Air Station Fort Worth, Texas (VR-59) and Naval Air Station Jacksonville, Florida (VR-58).

The US Air Force has bought two ex-Fordair BBJs, which are designated C-40B.

Powerplants

737-600 - Two 86.7kN (19,500lb) CFM56-7B18 turbofans, or 101kN (22,700lb) CFM56-7B22s on high gross weight version. 737-700 - Two 91.6kN (20,600lb) CFM56-7B20s or 101kN (22,700lb) CFM56-7B24s on HGW version.

Performance

Typical cruising speed Mach 0.785. Max certificated altitude 41,000ft. 737-600 - Range with 110 pax 2480km (1340nm) or 5648km (3050nm) for HGW version. 737-700 - Range with 126 pax 2852km (1540nm) or 6037km (3260nm) for HGW version.

Weights

737-600 - Operating empty 37,104kg (81,800lb), max takeoff 56,245kg (124,000lb), HGW max takeoff 65,090kg (143,500lb). 737-700 - Operating empty 38,147kg (84,100lb), max takeoff 60,330kg (133,000lb), HGW MTOW 70,080kg (154,500lb).

Dimensions

737-600 - Wing span 34.31m (112ft 7in), length 31.24m (102ft 6in), height 12.57m (41ft 3in). Wing area 125.0m2 (1344sq ft).

737-700 - Same except length 33.63m (110ft 4in), height 12.55m 41ft 2in).

Capacity

Flightcrew of two. 737-600 - 110 passengers in two classes or 132 in a single class. 737-700 - 126 in two classes or 149 in a single class.

Boeing 737-500

The 737-500 is the shortest and smallest member of the second generation 737-300/-400/-500 family, and the last to be developed.

When the new stretched 737-300 first appeared it was intended to supplement, rather than replace, the 737-200. However the evolution of the 737-300 into a family of models led to the development of a new model comparable in size to the 737-200, but offering better fuel economy and extensive commonality with the 737-300 and -400 models. This was the 737-500, known before its May 1987 formal launch as the 737-1000.

Like the preceding 737-300 and 737-400, the 737-500 is powered by CFM International CFM56s turbofans, in this case either 82.3kN (18,500lb) CFM563B1s or 89.0kN (20,000lb) CFM56-3C-1s. All three second generation 737 models share extensive systems and structure commonality, and a common aircrew type rating. These benefits offer real cost savings to an airline with two or more variants of the family in its fleet.

The 737-500 is 31.01m (101ft 9in) in length, comparable to the 737-200's 30.53m (100ft 2in) length, and as such is a viable direct replacement for the earlier type. Like the 300 and 400, a higher gross weight longer range version is offered, featuring auxiliary fuel tanks and uprated engines.

The 737-500's first flight occurred on June 30 1989, FAA certification was awarded on February 12 1990, with service entry later that same month.

The 737-500's main appeal is for operators of large 737-400 and 737-300 fleets, as because the 500 is a shortened development of the 300, it still carries much of the structural weight needed for the higher weight models. This makes it less efficient than if it was designed specifically for its size category, however for operators of large 737-300/400 fleets, the extensive commonality benefits more than compensate for this.

Powerplants

Two 82.3kN (18,500lb) CFM International CFM563B1 turbofans, or 89.0kN (20,000lb) CFM56-3C-1s.

Performance

Max cruising speed 912km/h (492kt), economical cruising speed 795km/h (430kt). Standard range with max passengers 2815km (1520nm), higher gross weight option range with max passengers 4444km (2400nm).

Weights

Operating empty (standard and high gross weight models) 31,983kg (70,510lb), standard max takeoff 52,390kg (115,500lb), high gross weight max takeoff 60,555kg (133,500lb).

Dimensions

Wing span 28.88m (94ft 9in), length 31.01m (101ft 9in), height 11.13m (36ft 6in). Wing area 105.4m2 (1135sq ft).

Capacity

Flightcrew of two. Typical two class seating for 108 (eight first and 100 economy), or max single class seating for 132 at 76cm (30in) pitch.

Boeing 737-400

Boeing announced it was developing a new higher capacity version of the fast selling 737-300 in June 1986.

The new aeroplane, the 737-400, was developed as a 150 seat class 727 replacement. Although Boeing had initially developed the 180 to 200 seat 757 to replace the successful 727, there still existed a considerable market for a near direct size replacement for the popular trijet. By developing the 737-400 as a minimum change stretch of the 737-300, Boeing was also able to offer considerable commonality, and thus cost, benefits to operators already with the 737-300, and to a lesser extent, the 737-200 in their fleets.

The major change of the 737-400 over the smaller 300 is a 3.05m (10ft 0in) fuselage stretch, consisting of a 1.83m (6ft 0in) stretch forward and a 1.22m (4ft 0in) plug rear of the wing. The stretch increases maximum passenger seating to 188. To cope with the increased weights, more powerful CFM56s are fitted. Other changes are minor, such as a tail bumper fitted to protect against over rotation at takeoff, something that could have become a problem due to the increased fuselage length.

A higher gross weight longer range version is offered. It features increased fuel capacity, and strengthened undercarriage and structures, but is otherwise identical to the standard 737-400.

The first flight of the 737-400 occurred on February 19 1988 and it entered airline service in October that year with Piedmont. Of the 737-300/-400/-500 family the 400 has proven the most successful member behind the 300, its larger capacity and transcontinental US range meaning it has found a very useful market for Boeing as a 727 replacement. However the 737-400 does face stiff competition from the similar size Airbus A320, which has higher levels of technology, longer range and is faster (but is also heavier).

Powerplants

Two 97.9kN (22,000lb) CFM International CFM563B2 turbofans, or optionally 104.5kN (23,500lb) CFM563C1s.

Performance

Max cruising speed 912km/h (492kt), long range cruising speed 813km/h (439kt). Standard version range with max payload 4005km (2160nm), typical range with 146 passengers 3630km (1960nm). High gross weight option range with 146 passengers 3850km (2080nm).

Weights

Standard version operating empty 34,564kg (76,200lb), max takeoff 62,820kg (138,500lb). High gross weight operating empty 34,827kg (76,780lb), max takeoff 68,040kg (150,000lb).

Dimensions

Wing span 28.88m (94ft 9in), length 36.45m (119ft 7in), height 11.13m (36ft 6in). Wing area 105.4m2 (1135sq ft).

Capacity

Flightcrew of two. Typical two class seating for 146 (eight premium, 138 economy), typical all economy for 159 at 81cm (32in) pitch, or max seating for 188.

Boeing 737-300

The 737-300 is the first of the three member second generation CFM56 powered 737 family, which also comprises the stretched 737-400 and shortened 737-500. The success of the second generation Boeing 737 family pushed sales of the mark to over 3000, a record for a commercial jetliner.

Boeing announced it was developing the 737-300 in March 1981. This new variant started off as a simple stretch over the 737-200 but Boeing decided to adopt the CFM International CFM56 high bypass turbofan (jointly developed by General Electric and SNECMA) to reduce fuel consumption and comply with the then proposed International Civil Aviation Organisation Stage 3 noise limits.

Despite the all new engines and the 2.64m (104in) fuselage stretch, the 737-300 retains 80% airframe spares commonality and shares the same ground handling equipment with the 737-200. A number of aerodynamic improvements were incorporated to further improve efficiency including modified leading edge slats and a new dorsal fin extending from the tail. Another feature was the flattened, oval shaped engine nacelles, while the nosewheel leg was extended to increase ground clearance for the new engines. Other internal changes include materials and systems improvements first developed for the 757 and 767 programs, including an early generation EFIS flightdeck (with four colour CRT screens).

The 737-300 flew for the first time on February 24 1984, while first deliveries were from November 1984. Since that time well over 1000 737-300s have been sold and it forms the backbone of many airlines' short haul fleets.

The stretched 737-400 and shortened 737-500 are described separately.

Powerplants

Two 89.0kN (20,000lb) CFM International CFM563B1 turbofans, or optionally two 97.9kN (22,000lb) CFM563B2s.

Performance

Max cruising speed 908km/h (491kt), long range cruising speed 794km/h (429kt). Range with 128 passengers and standard fuel 3362km (1815nm), range with 128 pax and max fuel 4973km (2685nm). High gross weight version max range 6300km (3400nm) with 140 passengers.

Weights

Operating empty 32,881kg (72,490lb), standard max takeoff 56,740kg (124,500lb), high gross weight option 62,823kg (138,500lb).

Dimensions

Wing span 28.88m (94ft 9in), length 33.40m (109ft 7in), height 11.13m (36ft 6in). Wing area 105.4m2 (1135sq ft).

Capacity

Flightcrew of two. Typical two class seating for 128 (eight premium class four abreast and 120 economy class six abreast), standard one class seating for 141 at six abreast and 81cm (31in) pitch, max seating for 149 at 76cm (30in) pitch.

Boeing 737-100/200

The 737-100 and 200 are the first generation production models of the world's most successful jet airliner family, Boeing's 737 twinjet.

The 737 was conceived as a short range small capacity airliner to round out the Boeing jet airliner family beneath the 727, 720 and 707. Announced in February 1965, the 737 was originally envisioned as a 60 to 85 seater, although following consultation with launch customer Lufthansa, a 100 seat design was settled upon. Design features included two underwing mounted turbofans and 60% structural and systems commonality with the 727, including the same fuselage cross section (making it wider than the competing five abreast DC-9 and BAC-111).

The 737-100 made its first flight on April 9 1967 and entered service in February 1968 with Lufthansa, while the last of 30 built was delivered to Malaysia-Singapore Airlines in October 1969.

By this time however the larger capacity 1.93m (6ft 4in) stretched 737-200 was in service after it had made its first flight on August 8 1967. First delivery, to United, was that December.

Developments of the -200 include the -200C convertible and quick change -200QC, while an unprepared airfield kit was also offered. The definitive Advanced 737-200 appeared in 1971, featuring minor aerodynamic refinements and other improvements.

Sales of the 737-200 far exceeded that of the shorter -100 and the 737-200 remained in production until 1988, by which time it had been superseded by the improved 737-300, after 1114 had been built. Many have been fitted with Stage 3 engine hushkits, and a number of passenger aircraft have been converted with cargo doors.

The USAF ordered 19 as navigation trainers, and some were later converted to standard transport aircraft as CT-43A. A few other air forces received 737-200s to serve in general transport, surveillance or VIP transport tasks.

Powerplants

737-100 - Two 62.3kN (14,000lb) Pratt & Whitney JT8D-7 turbofans. 737-200 - Two 64.5kN (14,500lb) JT8D-9As, or two 68.9kN (15,500lb) JT8D-15s, or two 71.2kN (16,000lb) JT8D-17s, or two 77.4kN (17,400lb) JT8D-17Rs with automatic reverse thrust.

Performance

737-100 - Max speed 943km/h (509kt), economical cruising speed 852km/h (460kt). Range with max fuel 2855km (1540nm).737-200 - Max speed 943km/h (509kt), max cruising speed 927km/h (500kt), economical cruising speed 796km/h (430kt). Range with 115 passengers and reserves between 3520km (1900nm) and 4260km (2300nm) depending on weight options and engines.

Weights

737-100 - Empty 25,878kg (57,000lb), max takeoff 49,940kg (110,000lb). 737-200 - Operating empty 27,448kg (60,600lb), max takeoff 52,390kg (115,500lb), or optionally 58,740kg (129,500lb).

Dimensions

737-100 - Wing span 28.35m (93ft 0in), length 28.67m (94ft 0in), height 11.29m (37ft 0in). Wing area 91.1m2 (980sq ft).737-200 - Same except for length 30.53m (100ft 2in).

Capacity

Flightcrew of two.

737-100 - Typical single class seating for 100. 737-200 - Typical single class seating for 115, max seating for 130 at 74cm (29in) pitch.737-200C/QC payload 15,545kg (34,270lb), consisting of pallets or containers.

Boeing 727-200

The 727-100 had been in service barely a year when Boeing began serious consideration of a stretched, greater capacity development.

This resulted in the 727-200, which Boeing announced it was developing in August 1965. The 727-200 was essentially a minimum change development of the 100, the only major change being the 6.10m (20ft) fuselage stretch, which increased maximum seating to 189 passengers. The 727-200's stretch consisted of two 3.05m (10ft) plugs, one forward and one rear of the wing. Otherwise the 727-100 and 200 shared common engines, fuel tank capacity and the same maximum takeoff weight.

The first flight of the 727-200 occurred on July 27 1967, with certification granted in late November that year. The -200 was placed into service by launch customer Northeast Airlines (this airline was later acquired by Delta) the following month, by which time total 727 orders for both models had exceeded 500.

The 727-200 helped broaden the sales appeal of the 727 considerably and snared significant sales. However the 200 was restricted by its relatively short range, due to it having the same fuel capacity as the 727-100, so Boeing developed the increased range Advanced 727-200. First flown in March 1972 changes introduced on the Advanced model included increased fuel capacity, and thus range, the option of more powerful engines, quieter engine nacelles and strengthened structure. The Advanced remained the primary 727-200 production model until production ceased in 1984.

The 727-200 remains popular with passengers and pilots but it does not meet Stage 3 noise requirements. To overcome this a number of hushkit programs are on offer while Valsan converted 23 727s to its Stage 3 compliant Quiet 727 standard (before the company collapsed). This retrofit included installing JT8D-217s on the outer pylons and acoustic treatment of the centre engine. Other 727s have been fitted with winglets for improved performance.

Powerplants

Three 64.5kN (14,500lb) Pratt & Whitney JT8D-9 turbofans, or 67.2kN (15,000lb) JT8D-11s, or 68.9kN (15,500lb) JT8D-15s or 71.1kN (16,000lb) JT8D-17s (Advanced only), or 77.3kN (17,400lb) JT8D-17Rs (Advanced only).

Performance

Advanced 727-200 - Max speed 1017km/h (549kt), max cruising speed 953km/h (515kt), economical cruising speed 865km/h (467kt). Range with max payload 3965km (2140nm), range with max fuel 4450km (2400nm).

Weights

Advanced 727-200 - Operating empty 45,360kg (100,000lb), max takeoff 95,030kg (209,500lb).

Dimensions

Wing span 32.92m (108ft 0in), length 46.69m (153ft 2in), height 10.36m (34ft 0in). Wing area 157.9m2 (1700sq ft).

Capacity

727-200 - Max seating for 189 at six abreast and 76cm (30in) pitch, typical two class seating for 14 premium class and 131 economy class passengers.727-200F - Typical max payload comprises 11 2.23m x 3.17m (7ft 4in x 10ft 5in) pallets.

Boeing 727-100

The 727 short to medium range trijet is the world's second most successful jet airliner built.

Initial design studies began in 1956, although for a time it appeared that a new short/medium range airliner would not be built at all due to Boeing's financial position before sales of the 707 had taken off. Boeing persisted however and serious development of the 727 beginning in June 1959. The program was launched on the strength of orders for 80 from Eastern and United in 1960.

The resulting Boeing Model 727 pioneered the rear trijet configuration, with power from three specially designed Pratt & Whitney JT8D turbofans (although RollsRoyce Speys were originally considered). The trijet design was settled upon as it gave the redundancy of three engines, better climb performance than a twin and improved operating economics over a four engine jet. The 727 also introduced an advanced wing design with the first airliner application of triple slotted Krueger flaps. The 727 retained the 707's fuselage cross section, but with a redesigned smaller lower fuselage due to the need to carry less baggage on shorter range flights, and it has limited parts commonality with the 707 and 720. The 727 was also the first Boeing airliner to feature an APU (auxiliary power unit).

The prototype 727 first flew on February 9 1963, with certification granted in December that year. The first 727 entered service with Eastern Airlines on February 9 the following year.

Development of the initial 727-100 resulted in a small family of sub variants, including higher gross weight options for the basic passenger carrying 727, the 727-100C Convertible and 727-200QC Quick Change, both with a large freight door on the forward left hand side of the fuselage. Many were subsequently converted to pure freighters. The stretched 727-200 is described separately.

Production of the 727-100 ceased in 1973 but one recent notable development was Dee Howard in the USA upgrading a number of 727-100 freighters for express freight operator UPS. The major feature of the upgrade was reengining with RollsRoyce Tays, which improves performance, reduces fuel consumption and more importantly, allows the aircraft to meet Stage 3 noise requirements.

Powerplants

727-100 - Three 62.3kN (14,000lb) Pratt & Whitney JT8D-7 turbofans.

Performance

Max speed 1017km/h (549kt), max cruising speed 960km/h (518kt), economical cruising speed 917km/h (495kt). Range with max payload 5000km (2700nm).

Weights

727-100 - Empty equipped 36,560kg (80,602lb), max takeoff 72,570kg (160,000lb).

Dimensions

727-100 - Wing span 32.92m (108ft 0in), length 40.59m (133ft 2in), height 10.36m (34ft 0in). Wing area 157.9m2 (1700sq ft).

Capacity

Flightcrew of three (two pilots and flight engineer). Typical two class seating for 94, max seating for 131.

Boeing 720

The 720 is a smaller capacity, lighter, medium range variant of the 707, given its own model number to indicate significant engineering changes.

Introduced in 1959, the 720 (originally designated 707-020) retained the same basic structure as the 707-120, but was 2.54m (8ft 4in) shorter, which reduced seating to 112 (38 + 74) in a typical two class arrangement. Other changes were made to the wing which introduced full span leading edge flaps, while a glove between the inner engines and the fuselage increased wing sweep and wing area and decreased the wing's thickness/chord ratio. The changes to the wing made it more aerodynamically efficient, permitting higher cruising speeds and lowered minimum speeds (which aided field performance).

Like the early 707s the first 720s had JT3C turbojets, although less powerful models lacking water injection because of the 720's lighter weight. Compared with the 707-120 the 720 also had reduced fuel capacity and a lower max takeoff weight. But many components were interchangeable between the 720 and 707, while inside the cabin the 720 and 707 shared the same passenger interior and flightdeck.

The initial 720 (bound for launch customer United) first flew on November 23 1959. Certification was awarded on June 30 1960, and entry into service with United Airlines was on July 5 that year.

The availability of the far more fuel efficient Pratt & Whitney JT3D turbofan resulted in the 720B, which was powered by either JT3D1s or 3s. First flight of the 720B was on October 6 1960, with certification awarded on March 3 1961. The 720B also featured a higher maximum zero fuel weight (significantly boosting payload/range) and an increased max takeoff weight due to the heavier turbofan engines.

Major 720 operators included American Airlines (a number of its 720s were converted to 720Bs with turbofan engines), United, Continental, Eastern, Northwest Orient and Western, while operators outside the US included Lufthansa and Avianca.

Today (early 2002) three 720s are believed to be in use as corporate transports, and two are used by Pratt & Whitney as engine testbeds.

Powerplants

720B - Four 75.6kN (17,000lb) Pratt & Whitney JT3D1 turbofans or four 80kN (18,000lb) JT3D3s.

Performance

720B - Max speed 1009km/h (545kt), max cruising speed 983km/h (530kt), economical cruising speed 896km/h (484kt). Range with maximum payload and no reserves 6687km (3610nm), range with max fuel 8428km (4550nm).

Weights

720B - Operating empty 51,203kg (112,883lb), max takeoff 106,140kg (234,000lb).

Dimensions

Wing span 39.88m (130ft 10in), length 41.68m (136ft 9in), height 12.66m (41ft 7in). Wing area 234.2m2 (2521sq ft).

Capacity

Flightcrew of three comprising two pilots and a flight engineer. Typical seating for 112 in two classes, max seating for 149, later approved (for Eastern Air Lines) for 165.

Boeing 717

The 100 seat 717 is the latest development of the popular DC-9/MD-80/MD-90 family and the only Douglas airliner which Boeing (which merged with McDonnell Douglas in 1997) plans to retain in its product line-up. It is designed for high cycle, short range regional airline operations.

McDonnell Douglas first announced the MD-95 at the Paris Airshow in June 1991. At the time MDC anticipated a formal program launch by late 1991 and a first flight in July 1994. As it happened program launch was not until October 1995 when US airline ValuJet (now AirTran Airlines) ordered 50 and optioned 50.

In January 1998 Boeing (following the August 1997 Boeing/McDonnell Douglas merger) relaunched the aircraft as the 717-200 (the second use of the Boeing designation "717", as this was previously allocated to the military C-135/KC-135 family). First flight took place on September 2 1998, followed by a second development 717 on October 26. Certification was awarded on September 1 1999 while the first delivery, to AirTran, was on September 23 that year.

Initially MDC studied powering the MD-95 with Pratt & Whitney JT8D-218s or Rolls-Royce Tays. In February 1994 however MDC announced it had chosen the new BMW Rolls-Royce (now just Rolls-Royce) BR715 over the JT8D-200 and an engine from the proposed "Project Blue" teaming of General Electric, Snecma, MTU and P&W.

Other 717-200 features include a fuselage 1.45m (4ft 9in) longer than the DC-9-30's, a wing based on the DC-9-34's, an advanced six LCD screen Honeywell EFIS flightdeck, and a cabin interior similar to that developed for the MD-90. It is offered in standard 717-200BGW (Basic Gross Weight) and extended range 717-200HGW (High Gross Weight) forms. In addition, 80 seat shortened 717-100 (formerly MD-95-20) and 120 seat stretched 717-300 (formerly MD-95-50) models have been studied, as has a business jet variant.

Companies participating in 717 production include Alenia (fuselage), Korean Air (nose), AIDC of Taiwan (empennage), ShinMaywa of Japan (engine pylons and horizontal stabilizers), Israel Aircraft Industries (undercarriage), and Fischer of Austria (interior). Final assembly is at Boeing's Long Beach plant, in the same building that the DC-9 and MD-80 were built in.

Initial orders and operators are:

AeBal, Airtran, Bangkok Air, Bavaria International Leasing, Hawaiian Airlines, Impulse Airlines, Midwest Express Airlines, Olympic Aviation, Pembroke Leasing, Qantas Link, Siam Reap Air, Trans World Airlines, and Turkmenistan Airlines.

Powerplants

717-200BGW - Two 82.3kN (18,500lb) Rolls-Royce BR715-A1-30 turbofans.717-200HGW - Same or optionally 89.6kN (20,000lb) or 93.4kN (21,000lb) BR715s.

Performance

717-200BGW - Cruising speed 811km/h (438kt). Range with 106 passengers 2545km (1375nm). 717-200HGW - Cruising speed same. Range with 106 passengers 3815km (2060nm).

Weights

717-200BGW - Operating empty 31,674kg (69,830lb), max takeoff 49,940kg (110,100lb) or 51,710kg (114,000lb).717-200HGW - Operating empty 32,110kg (70,790lb), max takeoff 54,885kg (121,000lb).

Dimensions

Wing span 28.44m (93ft 3in), length 37.80m (124ft 0in), height 8.87m (29ft 1in). Wing area 93.0m2 (1000.7sq ft).

Capacity

Flightcrew of two. Typical two class seating for 106 passengers at five abreast in main cabin. Single class seating for 117.

Boeing 707

The 707's jet speed, long range, high seating capacity and operating economics revolutionised airliner travel when it was introduced into service in 1958. The 707 also laid the foundations for Boeing's dominance of the jet airliner market.

Recognising the jet engine's potential for commercial aviation, Boeing (at great financial risk) decided to develop a jet powered transport that could fulfil military tanker transport roles but be easily adapted to become an airliner. The resulting prototype, known as the 367 Dash 80, flew for the first time on July 16 1954. Impressed, the US Air Force ordered a larger version, with a wider fuselage (12 ft, vs 11 ft for the Dash 80) into production as the KC-135 tanker/transport (more than 800 were built). At first, Boeing wanted to sell the same size aircraft to the airlines, but the airlines insisted on an even larger airplane, which Douglas promised to build (this became the DC-8). Boeing finally relented, designing the 707 as a longer aircraft with a slightly wider fuselage (12 ft 4 in).

The first production 707 (a 707-120 for Pan Am) flew on December 20 1957, and entered service later the following year. Developments of the 707-120 include the similar 707-220, the shorter 138 for Qantas, and the stretched 707-320, which flew in July 1959. The 707-120 and 320 were later reengined with JT3D turbofans (in place of the original JT3 and JT4 turbojets) to become the 707-120B, and the 707-320B respectively. The 707-320C was a convertible model, the 707-420 was powered by RollsRoyce Conways, while the proposed CFM-56 powered 707-700 upgrade was flight tested in the late 1970s but never entered production.

Most civil 707s in service today have been converted to freighters, while a number are used as corporate transports.

Many air forces have bought 707s, new or converted second-hand aircraft, for general transport, aerial refuelling, and electronic warfare. The E-3 Sentry is a dedicated airborne warning and control system (AWACS) platform with a large rotodome above the fuselage. The E-6 Mercury performs the TACAMO (Take Charge and Move Out) role with the US Navy, maintaining communication with the ballistic missile submarines. The E-8 J-Stars (Joint Surveillance Target Attack Radar System) performs the battlefield control role. Other military 707s received the designations C-137, or C-18, but many others have no special military designation.

Powerplants

707-120B - Four 75.6kN (17,000lb) Pratt & Whitney JT3D-1 turbofans. 707-320B - Four 80kN (18,000lb) JT3D-3s or four 84.4kN (19,000lb) JT3D-7s.

Performance

707-120B - Max speed 1010km/h (545kt), max cruising speed 1000km/h (540kt), economical cruising speed 897km/h (484kt). Range with max payload 6820km (3680nm), range with max fuel 8485km (4580nm). 707-320B - Max speed 1009km/h (545kt), max cruising speed 974km/h (525kt), long range cruising speed 885km/h (478kt). Range with max passengers 6920km (3735nm), range with max fuel and 147 passengers 9265km (5000nm).

Weights

707-120B - Operating empty 55,589kg (122,533lb), max takeoff 116,575kg (257,000lb). 707-320B - Empty 66,406kg (146,400lb), max takeoff 151,315kg (333,600lb).

Dimensions

707-120B - Wing span 39.90m (130ft 10in), length 44.07m (144ft 6in), height 12.94m (42ft 5in). Wing area 226.3m2 (2433sq ft). 707-320B - Wing span 44.42m (145ft 9in), length 46.61m (152ft 11in), height 12.93m (42ft 5in). Wing area 283m2 (3050sq ft).

Capacity

Flightcrew of three or four. 707-120 max seating for 179, or 110 in two classes (44 first and 66 economy).707-320B - Max seating for 219, or 189 single class at 81cm (32in) pitch, or 147 in two classes.

Convertible or freighter versions - 13 A type containers.