Boeing 717

The Boeing 717 is a twin-engine, single-aisle jet airliner, developed for the 100-seat market. The airliner was designed and marketed by McDonnell Douglas as the MD-95, a third-generation derivative of the DC-9. Capable of seating of up to 117 passengers, the 717 has maximum range of 2,060 nautical miles (3,820 km). The aircraft is powered by two Rolls-Royce BR715 turbofan engines.

The first order was placed in October 1995; McDonnell Douglas and Boeing merged in 1997[2] prior to production, and the first planes entered service in 1999 as the Boeing 717. Production ceased in May 2006 after 156 were produced.

Development

Background

Douglas Aircraft developed the DC-9 to be a short-range companion to their larger four engined DC-8 in the early 1960s. The DC-9 was an all-new design, using two rear fuselage-mounted Pratt & Whitney JT8D turbofan engines, a small, highly efficient wing, and a T-tail. The DC-9 first flew in 1965 and entered airline service later that year. When production ended in 1982 a total of 976 DC-9s had been produced.

The McDonnell Douglas MD-80 series was introduced into airline service in 1980. The design was the second generation of the DC-9. It was a lengthened DC-9-50 with a higher maximum take-off weight (MTOW) and higher fuel capacity, as well as next-generation Pratt and Whitney JT8D-200 series engines. Nearly 1,200 MD-80s were delivered from 1980 to 1999.

The MD-90 was developed from the MD-80 series. It was launched in 1989 and first flew in 1993. The MD-90 was longer, and featured a glass cockpit (electronic instrumentation) and more powerful, quieter, fuel efficient V2525-D5 engines, with the option of upgrading that to a V2528 engine. Only 117 MD-90 airliners were built.

MD-95

The MD-95 traces its history back to 1983 when McDonnell Douglas outlined a study named the DC-9-90. During the early 1980s, as production of the DC-9 family moved away from the smaller Series 30 towards the larger Super 80 (later redesignated MD-80) variants, Douglas proposed a smaller version of the DC-90 to fill the gap left by the DC-9-30. Dubbed the DC-9-90, the aircraft was revealed in February 1983 and was to be some 25 ft 4 in (7.72 m) shorter than what was then the DC-9-81 giving it an overall length of 122 ft 6 in (37.34 m) The aircraft was proposed with a 17,000 lbf (76 kN) thrust version of the JT8D-200 series engine, although the CFM56-3 was also being considered. Sized to seat up to 117 passengers, the DC-9-90 was to be equipped with the DC-9's wing with 2 ft (0.61 m) tip extensions, rather than the more heavily modified increased area of the MD-80. The aircraft had a design range of around 1,500 nmi (2,800 km), with an option to increase to 2,000 nmi (3,700 km), and a gross weight of 112,000 lb (51,000 kg). The DC-9-90 was designed to meet the needs of the newly deregulated air transport industry in the US, however, the development of the short fuselage MD-80 was postponed as a result of the downturn in business in the recession of the early 1980s. When McDonnell Douglas did develop a smaller version of the MD-80, it simply shrunk the aircraft to create the MD-87, rather than offer a lower thrust lighter aircraft that was more comparable to the DC-9-30. With its relatively high MTOW and powerful engines, the MD-87 essentially became a special mission aircraft and could not compete with the all new 100-seaters that were being developed. Although an excellent aircraft for specialized roles, the MD-87 has not really sold on its own, and tends to rely heavily on its commonality factor which has generally limited sales to existing MD-80 operators.

During early 1991, McDonnell Douglas revealed that it was again considering the development of a specialized 100-seat version of the MD-80 family, which was initially dubbed the MD-87-105 (105 seats). The new lighter aircraft was to be some 8 ft (2.4 m) shorter than the MD-87, and would be powered by engines in the 16,000–17,000 lbf (71–76 kN) thrust class.[4]

Following the signature by McDonnell Douglas, Pratt & Whitney and the China National Aero-Technology Import Export agency of a memorandum of understanding to develop a 105-seat version of the MD-80, McDonnell Douglas announced at the 1991 Paris Airshow the development of the new 105-seat version which was now designated the MD-95.[4] The "MD-95" name was selected to reflect the anticipated year deliveries would begin.[5] McDonnell Douglas first offered the airliner for sale in 1994.[5][6] With an overall length of 122 ft 5 in (37.31 m), and a MTOW of 118,400 lb (53,700 kg), what McDonnell Douglas was proposing at that stage was very similar to the DC-9-90 design of 1983.

In early 1994 the MD-95 re-emerged bearing far more similarity to the DC-9-30. Indeed the aircraft's specification in terms of weight, dimensions, and fuel capacity are almost identical. The major changes included a fuselage "shrink" back to 119 ft 4 in (36.37 m) length (same as the DC-9-30), and the reversion to the original DC-9 wing of 93 ft 5 in (28.47 m) span. At the time of the redefinition, McDonnell Douglas said that it expected the MD-95 to grow into a family of aircraft with the capability of increased range and seating capacity.[4]

The MD-95 was developed to satisfy the market need to replace early DC-9 models, then approaching 30 years old. The MD-95 project was a complete overhaul of the system, going back to the original DC-9-30 design and reinventing it for modern transport with new engines, cockpit and other more modern systems.[5] Historically, aircraft shrinks have sold poorly, examples of such aircraft in addition to the MD-87 include the Boeing 747SP, Boeing 737-600, Airbus A318, and Airbus A340-200.

Longtime McDonnell Douglas customer Scandinavian Airlines System (SAS) chose the Boeing 737-600 for its 100-seater over the MD-95 in March 1995.[5] Then in October 1995, US discount carrier ValuJet signed an order for 50 MD-95s, plus 50 options.[5] McDonnell Douglas president Harry Stonecipher felt that launching MD-95 production on the basis of this small order was only a small risk, explaining that further orders would "take a while longer".[7] The ValuJet order was the only order received for some two years.[8]

Engines

As first proposed, the MD-95 was to be powered by a 16,500 lbf (73,000 N) thrust derivative of the JT8D-200 series, and the Rolls-Royce Tay 670 was also considered as an alternative. This was confirmed in January 1992, when Rolls-Royce and McDonnell Douglas signed an MoU concerning the Tay-powered MD-95. McDonnell Douglas said that the MD-95 project would cost only a minimal amount to develop, as it was a direct offshoot of the IAE-powered MD-90.

During 1993 McDonnell Douglas seemed to be favoring a relife program of the DC-9-30, under the program name DC-9X, to continue its presence in the 100-120 seat market, rather than concentrating on the new build MD-95. During its evaluation of the various engines available for the proposed re-engining component of DC-9X, McDonnell Douglas found the BMW Rolls-Royce BR700 engine an ideal candidate and the BMW Rolls-Royce BR700 engine was selected to power the aircraft on February 23, 1994.

Production

McDonnell Douglas was planning for all MD-95 assembly to be undertaken in China, as an offshoot of the Trunkliner program, for which McDonnell Douglas had been negotiating to have up to 150 MD-90s built in China. The MD-90 Trunkliner deal was finalized in June 1992, but the contract was for a total of 40 aircraft, including 20 MD-80Ts and 20 -90Ts. The MD-80 has been license built in Shanghai since the 1980s. However in early 1993, MDC said that it was considering sites outside China, and was later seeking alternative locations for the assembly line. In 1994, McDonnell Douglas sought global partners to share development costs. It also began a search for a low-cost final assembly site. Halla Group in South Korea was selected to make the wings; Alenia of Italy the entire fuselage; Aerospace Industrial Development Corp. of Taiwan, the tail; ShinMaywa of Japan, the horizontal stabilizer; and a manufacturing division of Korea Air Lines, the nose and cockpit.[4]

In an unprecedented move, McDonnell Douglas announced on November 8, 1994 that final assembly would be taken away from the longtime Douglas plant in Long Beach, California. Instead, it tapped a modifications and maintenance operation, Dalfort Aviation in Dallas, Texas, to assemble the MD-95. In early 1995, management and unions in Long Beach reached an agreement to hold down wage costs for the life of the MD-95 program and McDonnell Douglas canceled the preliminary agreement with Dalfort.[9]

Rebranding

An AirTran Airways Boeing 717-200 climbing away in 2006.

After McDonnell Douglas merged with Boeing in August 1997, most industry observers expected that Boeing would cancel development of the MD-95. However, Boeing decided to go forward with the design under a new name, Boeing 717. Some believed Boeing had skipped the 717 model designation when the 720, and then the 727 followed the 707. The 717 name had actually been used within the company to refer to the KC-135 Stratotanker. 717 had also been used to promote an early design of the 720 to airlines before it was modified to meet market demands. A Boeing historian notes that the air force plane had the designation "717-100" and the commercial airliner had the designation "717-200". The lack of a widespread use of the 717 name left it available to rebrand the MD-95.

At first Boeing had no more success selling the 717 than McDonnell Douglas. Even the original order for 50 was no certainty in the chaotic post-deregulation US airline market. Assembly started on the first 717 in May 1997.[12] The aircraft had its roll out ceremony on June 10, 1998. The 717's first flight took place on September 2, 1998. Following flight testing, the airliner was awarded a type certification on September 1, 1999. Its first delivery was to AirTran Airways in September 1999 and entered commercial service the following month.

Boeing's decision to go ahead with the 717 slowly began to pay off. Early 717 operators were delighted with the reliability and passenger appeal of the type and ordered more.[citation needed] The small Australian regional airline Impulse took a long-term lease on five 717s in early 2000 to begin an expansion into mainline routes. The ambitious move could not be sustained in competition with the majors, and Impulse sold out to Qantas in May 2001. This left Qantas with a more-or-less unwanted handful of 717s to spoil the efficiency of its fleet of large Boeing and small BAe 146 jets.

Within a few months, however, the abilities of the 717 became clear. It is roomier and faster than the BAe 146, cheaper to operate, and achieved a higher dispatch reliability, over 99%, than competing aircraft.[13] Maintenance costs are very low: a C check inspection, for example, takes three days and is required once in 6,000 flying hours.[citation needed] (For comparison, its predecessor, the DC-9 needed 21 days for a C check.) The new Rolls-Royce BR715 engine design is highly modular: none of the line-replaceable units takes more than an hour to exchange.[citation needed] Many 717 operators, even accidental ones like Qantas, become converts to the plane. Qantas bought more 717s, and other significant orders have come from Hawaiian Airlines and Midwest Airlines.

Boeing actively marketed the 717 to a number of large airlines, including Lufthansa and Northwest (who already operated a large fleet of DC-9 aircraft). Boeing also studied a stretched, higher-capacity version of the 717, to have been called 717-300, but decided against proceeding with the new model, fearing that it would encroach on the company's 737-700 model. Production of the original 717 continued. Boeing continued to believe that the 100-passenger market would be lucrative enough to support both the 717 and the 737-600, the smallest of the Next-Generation 737 series. While the aircraft were similar in overall size, the 737-600 was better suited to long-distance routes, while the lighter 717 was more efficient on shorter, regional routes.

The 100-seat market was overcrowded until 2001, but several potential competitors disappeared. BAe canceled its Avro RJX (an updated BAe 146 with modern engines); Fairchild Dornier closed its doors, taking the 728/928 project with it; and Bombardier canceled its new BRJ in favor of a less ambitious stretched 90-seat CRJ900. The remaining players are Boeing, Airbus with the A318, and Embraer with the E-195. The worldwide fleet was then largely made up of aging twinjets with relatively high operating costs, notably the DC-9, early model 737s, and the Fokker 100, plus the newer four-engined BAe 146, which is a prime prospect for refurbishment.

In 2001, Boeing began implementing a moving assembly line for production of the 717 and 737.[14] The moving line greatly reduced production time, which was to lead to lower production costs.[15]

Following the slump in airline traffic caused by reaction to the September 11, 2001 attacks in the USA, Boeing announced a review of the type's future. After much deliberation, it was decided to continue with production. Despite the lack of orders, Boeing had confidence in the 717's fundamental suitability to the 100-seat market, and in the long-term size of that market. After 19 worldwide 717 sales in 2000, and just 6 in 2001, Boeing took 32 orders for the 717 in 2002, despite the massive industry downturn. Additionally, the former Douglas facility at Long Beach was producing only 717s and C-17s at this time.

End of production

Increased competition from regional jets manufactured by Bombardier and Embraer took a heavy toll on sales during the airline slump after 2001. The beginning of the end came in December 2003 when Boeing lost a US$ 2.7 billion contract from Air Canada, who chose the Embraer E-Jets and Canadair CRJ over the 717.[16] In January 2005, citing slow sales, Boeing announced that it planned to end production of the 717 after it had met all of its outstanding orders.[17]

A major difficulty with the 717 model was its lack of commonality with other Boeing aircraft. The 717 had no commonality with other aircraft, even prior MD-80 and DC-9 aircraft upon which it was based. The trend with aircraft manufacturers, particularly Airbus, was to make a "family" of aircraft with similar cockpits and systems, which would require only one "type-rating" for a crew. That way, whatever size of aircraft that was required on a particular route—even changing down to the day if necessary—could be used with any of the crew type-rated for the family. Although the 717 had operating costs 10% lower than the A318, airlines considering the 717 could not take advantage of the cost savings gained through commonality. Airbus used a commonality approach starting with their A320 narrow-body family (including A318, A319, and A321), and Boeing embraced this concept with their Next-Generation 737-600, -700, -800, and -900 models. Embraer, in their new E-Jet family, also took this approach, offering four regional aircraft in a common family, the largest of which had operational capabilities very close to the 717.

The 156th and final 717 rolled off the assembly line in April 2006 for AirTran Airways, who were the 717's launch customer as well as its final customer. The final two Boeing 717s were delivered to customers AirTran and Midwest Airlines on May 23, 2006.[3] The 717 was the last commercial airplane produced at Boeing's Long Beach facility in Southern California.

Program milestones

• Announced: June 16, 1991 at the Paris Airshow as MD-95 program by McDonnell Douglas.[18]
• Approval to offer: July 22, 1994 Douglas got MDC board approval to offer the aircraft.
• First order: October 19, 1995 from ValuJet (later to become AirTran Airways) for 50 firm and 50 options for BR715-powered MD-95s.
• Roll out: June 10, 1998 at Long Beach, California.
• First flight: September 2, 1998.
• FAA certification: September 1, 1999.
• EASA (JAA) certification: September 16, 1999.
• Entry into service: October 12, 1999 with AirTran Airways on Atlanta-Washington DC route.
• 100th aircraft delivery: June 12, 2002 to AirTran Airways.
• Last delivery: May 23, 2006 to AirTran Airways (Now Southwest Airlines).

Design

The 717 features a two-crew cockpit that incorporates six interchangeable liquid-crystal-display units and advanced Honeywell VIA 2000 computers. The cockpit design is called Advanced Common Flightdeck (ACF) and is shared with the MD-11. Flight deck features include an Electronic Instrument System, a dual Flight Management System, a Central Fault Display System, and Global Positioning System. Category IIIb automatic landing capability for bad-weather operations and Future Air Navigation Systems are available. The 717 shares the same type rating as the DC-9 such that FAA approved transition courses for DC-9 and analog MD-80 pilots can be completed in 11 days.[24]

In conjunction with Parker Hannifin, MPC Products of Skokie, Illinois designed a fly-by-wire technology mechanical control suite for the 717 flight deck. The modules replaced much cumbersome rigging that had occurred in previous DC-9/MD-80 aircraft. The Rolls-Royce BR715 engines are completely controlled by an electronic engine system (FADEC — Full Authority Digital Engine Control) developed by BAE Systems, offering improved controllability and optimization over its predecessors.

Like its DC-9/MD-80/MD-90 predecessors, the 717 has a 2+3 seating arrangement in coach, providing only one middle seat per row, whereas other single-aisle twin jets often have 3+3 arrangement with two middle seats per row. Unlike its predecessors, McDonnell Douglas decided not to offer the 717 with the boarding flexibility of aft airstairs, with the goal of maximizing fuel efficiency through the reduction and simplification of as much auxiliary equipment as possible.

Variants

Three initial variants were proposed by McDonnell Douglas in 1993:

• MD-95-30: Baseline aircraft with 100-seat
• MD-95-30ER: extended range (with additional fuel), and
• MD-95-50: a slightly larger with standard capacity for 122 passengers.

Boeing 717 Business Express

Corporate version of 717-200, unveiled at EBACE Convention in Geneva, Switzerland, on 7 May 2003. Configurable for 40 to 80 passengers in first and/or business class interior (typically, 60 passengers with seat pitch of 52 in, 132 cm). Maximum range in HGW configuration with auxiliary fuel and 60 passengers was 3,140 nmi (5,815 km; 3,613 miles). The 717 Business Express complements BBJ family.

Undeveloped variants

• Boeing 717-100 (-100X): Proposed 86-seat version, formerly MD-95-20; four frames (6 ft 3 in, 1.9 m) shorter. Renamed -100X; wind tunnel tests began in early 2000; revised mid-2000 to eight-frame (12 ft 8 in, 3.86 m) shrink. Launch decision was deferred in December 2000 and again thereafter to an undisclosed date. Shelved by mid-2003.
• Boeing 717-100X Lite: Proposed 75-seat version, powered by Rolls-Royce Deutschland BR 710 turbofans; later abandoned.
• Boeing 717-300X: Proposed stretched version, formerly MD-95-50; studies suggest typical two-class seating for 130 passengers, with overall length increased to 138 ft 4 in (42.16 m) by addition of nine frames (five forward and four aft of wing); higher MTOW and space-limited payloads weights; additional service door aft of wing; and 21,000 lb (93.4 kN) BR 715C1-30 engines. AirTran expressed interest in converting some -200 options to this model. Was under consideration late 2003 by Star Group (Air Canada, Austrian Airlines, Lufthansa and SAS); interest was reported from Delta, Iberia and Northwest Airlines.

Boeing 707

The Boeing 707 is a mid-size, narrow-body four-engine jet airliner that was manufactured by Boeing Commercial Airplanes from 1958 to 1979. Its name is most commonly pronounced as "Seven Oh Seven". Versions of the aircraft have a capacity from 140 to 202 passengers and a range of 3,680 to 3,735 nautical miles (6,820 to 6,917 km). Developed as Boeing's first jet airliner, the 707 features a swept-wing design with podded engines. Dominating passenger air transport in the 1960s, and remaining common throughout the 1970s, the 707 is generally credited with ushering in the Jet Age.[4][5] Although it was not the first jetliner in service, the 707 was the first to be commercially successful. It established Boeing as one of the largest manufacturers of passenger aircraft, and led to the later series of aircraft with "7x7" designations. The subsequent 727, 737, and 757 also share elements of the 707's fuselage design.

The 707 was developed from the 367-80, a prototype jet aircraft which Boeing produced as a design study in 1954. A larger fuselage cross-section and other design modifications resulted in the initial production 707-120, powered by Pratt & Whitney JT3C turbojet engines, which first flew on December 20, 1957. Pan American World Airways inaugurated 707 service with a christening at National Airport on October 17, 1958, attended by President Eisenhower, followed by a transatlantic flight for VIPs (personal guests of founder Juan Trippe) from Baltimore's Friendship International Airport to Paris.[6] They began full 707 service with the type's first commercial flight on October 26, 1958. Subsequent derivatives included the shortened long-range 707-138 and the stretched 707-320, both of which entered service in 1959. A smaller short-range variant, the 720, was introduced in 1960. The 707-420, a version of the stretched 707 with Rolls-Royce Conway 508 turbofans, debuted in 1960, while Pratt & Whitney JT3D turbofans debuted on the 707-120B and 707-320B models in 1961 and 1962, respectively.

During its service career, the 707 has been used in a variety of roles, including domestic, transcontinental, and transatlantic operations. The 707 has also been used for cargo and military applications. A convertible passenger-freighter model, the 707-320C, entered service in 1963, and passenger 707s have been modified to freighter configurations. Military derivatives include the E-3 Sentry airborne reconnaissance aircraft and the C-137 Stratoliner VIP transports. During the 707's production run, Boeing produced and delivered a total of 1,011 aircraft, including the smaller 720 series. Over 800 military versions were also produced. As of August 2011, 10 examples of the 707 remain in airline service.

Development

Model 367-80 origins

Boeing, during and immediately after World War II, was known for its military aircraft. The company had produced innovative and important bombers, from the B-17 Flying Fortress and B-29 Superfortress, to the jet-powered B-47 Stratojet and B-52 Stratofortress. The company's civil aviation department lagged far behind Douglas and other competitors, the only noteworthy airliners being the Boeing 314 Clipper and 307 Stratoliner. During 1949–1950, Boeing embarked on serious studies for a new jet transport, realizing that any design must have the potential to fulfill both the military and civil markets. At the time, aerial refueling was increasingly becoming a standard operational technique, with over 800 KC-97 Stratotankers being on order. With the advent of the jet age, a new tanker was required to meets the USAF's fleet of jet-powered bombers; this was where Boeing's new design would potentially win military orders.

Boeing studied numerous wing and engine configurations for its new transport/tanker, some of which were based on the B-47 and C-97, before settling on 367-80. The "Dash 80" took less than two years from project launch in 1952 to rollout on May 14, 1954, then first flew on July 15, 1954. It was powered by the Pratt & Whitney JT3C turbojet engine, which was the civilian version of the J57 used on many military aircraft of the day, including the F-100 Super Sabre fighter and the B-52 bomber.The prototype was conceived as a proof of concept aircraft for both military and civilian use: The United States Air Force was the first customer for the design, using it as the basis for the KC-135 Stratotanker midair refueling platform.

It was far from certain that the passenger 707 would be profitable. At the time, Boeing was making nearly all of its money from military contracts: Its last passenger transport, the Boeing 377 Stratocruiser, had netted the company a $15 million loss before it was purchased by the Air Force as the KC-97 Stratotanker.[9] In a demonstration flight over Lake Washington outside of Seattle, on August 7, 1955, test pilot Tex Johnston performed a barrel roll in the 367-80 prototype.

The 132-inch (3,350 mm) wide fuselage of the Dash 80 was large enough to only fit four-abreast (two-plus-two) seating (in the manner of the Stratocruiser). Answering customers demands and under Douglas competition, Boeing soon realized that this would not provide a viable payload, so decided to widen the fuselage to 144 in (3,660 mm), the same as the KC-135 Stratotanker, which would allow five-abreast[disputed – discuss] seating—and the shared use of the KC-135's tooling.[10] However, Douglas Aircraft had launched its DC-8 with a fuselage width of 147 in (3,730 mm). The airlines liked the extra space and six-abreast seating, and so Boeing was obliged to increase the 707's width again to compete, this time to 148 in (3,760 mm).

Production and testing

The first flight of the first production 707-120 took place on December 20, 1957, and FAA certification followed on September 18, 1958.[12] A number of changes were incorporated into the production models from the prototype. A Krueger flap was installed along the leading edge between the inner and outer engines on early 707-120 and -320 models.[3][13]

Further developments

The initial standard model was the 707-120 with JT3C turbojet engines. Qantas ordered a shorter body version called the 707-138, which was a -120 that had six fuselage frames removed, three in front of the wings, and three aft. The frames in the 707 were each 20 inches (500 mm) apart, so this resulted in a net shortening of 10 ft (3 m) to 134 ft 6 in (41.0 m). Because the maximum takeoff weight remained the same 247,000 lb (112 t) as that of the -120, the 138 was able to fly the longer routes that Qantas needed.[13] Braniff International Airways ordered the higher-thrust version with Pratt & Whitney JT4A engines, the 707-220. The final major derivative was the 707-320, which featured an extended-span wing and JT4A engines, while the 707-420 was the same as the -320 but with Conway turbofan engines. British certification requirements relating to engine-out go-arounds also forced Boeing to increase the height of the tail fin on all 707 variants, as well as add a ventral fin, which was retrofitted on earlier -120 and -220 aircraft. These modifications also aided in the mitigation of dutch roll by providing more stability in yaw.

Though initially fitted with turbojet engines, the dominant engine for the Boeing 707 family was the Pratt & Whitney JT3D, a turbofan variant of the JT3C with lower fuel consumption as well as higher thrust. JT3D-engined 707s and 720s were denoted with a "B" suffix. While many 707-120Bs and 720Bs were conversions of existing JT3C-powered machines, 707-320Bs were available only as newly-built aircraft, as they had a stronger structure to support a maximum take-off weight increased by 19,000 lb (8,600 kg), along with minor modifications to the wing. The 707-320B series enabled non-stop westbound flights from Europe to the US west coast and from the US to Japan.

The final 707 variant was the 707-320C, (C for "Convertible"), which was fitted with a large fuselage door for cargo applications. This aircraft also had a significantly revised wing featuring three-section leading-edge flaps. This provided an additional improvement to takeoff and landing performance, and also allowed the ventral fin to be removed (although the taller fin was retained). 707-320Bs built after 1963 used the same wing as the -320C and were known as 707-320B Advanced aircraft.

Production of the passenger 707 ended in 1978. In total, 1,010 707s were built for civil use, though many of these found their way to military service. The purpose-built military variants remained in production until 1991.

Traces of the 707 are still found in the 737, which uses a modified version of the 707's fuselage, as well as the same external nose and cockpit configuration as the those of 707. These were also used on the previous 727, while the 757 also used the 707 fuselage cross-section. The Chinese government sponsored development of the Shanghai Y-10 during the 1970s, which was a near-carbon-copy of the 707; however, this did not enter production.

Design

Wings

The 707 wings are swept back at 35 degrees and, like all swept-wing aircraft, displayed an undesirable "Dutch roll" flying characteristic that manifested itself as an alternating yawing and rolling motion. Boeing already had considerable experience with this on the B-47 and B-52, and had developed the yaw damper system on the B-47 that would be applied to later swept wing configurations like the 707. However, many new 707 pilots had no experience with this phenomenon, as they were transitioning from straight-wing propeller-driven aircraft such as the Douglas DC-7 and Lockheed Constellation.

On one customer acceptance flight, where the yaw damper was turned off to familiarize the new pilots with flying techniques, a trainee pilot's actions violently exacerbated the Dutch roll motion and caused three of the four engines to be torn from the wings. The plane, a brand new 707-227, N7071, destined for Braniff, crash-landed on a river bed north of Seattle at Arlington, Washington, killing four of the eight occupants.[14]

In his autobiography, test pilot Tex Johnston described a Dutch roll incident he experienced as a passenger on an early commercial 707 flight. As the aircraft's movements did not cease and most of the passengers became ill, he suspected a misrigging of the directional autopilot (yaw damper). He went to the cockpit and found the crew unable to understand and resolve the situation. He introduced himself and relieved the ashen-faced captain who immediately left the cockpit feeling ill. Johnston disconnected the faulting autopilot and manually stabilized the plane "with two slight control movements".[15]

Engines

View of number 1 (top left) and 2 (center) Pratt & Whitney JT3D jet engines on the port side of a British Caledonian Boeing 707-320C. The number 1 engine mount (top) is different from the other three engines.

The 707s used engine-driven turbocompressors to supply high-pressure air for pressurization. The engines could not supply sufficient bleed air for this purpose without a serious loss of thrust. On many commercial 707s, the outer port (#1) engine mount is distinctly different from the other three, as this is the only engine not fitted with a turbocompressor, as seen in the adjoining image. With engines 2 through 4 being fitted with TCs, they provide the triple redundancy required of the aircraft's cabin pressurization and air-conditioning system.

The P&W JT3D-3B engines are readily identifiable by the large gray secondary air inlet doors in the nose cowl. These doors are fully open (sucked in at the rear) during takeoff to provide additional air. When the engines are throttled back to cruise, the doors are shut.

The 707 was the first commercial jet aircraft to be fitted with clamshell type thrust reversers on each of the four engines.

Upgraded engines

Pratt & Whitney, in a joint venture with Seven Q Seven (SQS) and Omega Air, has developed the JT8D-219[when?] as a re-engine powerplant for Boeing 707-based aircraft, calling their modified configuration a 707RE.[17] Northrop Grumman has selected the -219 to re-engine the United States Air Force's fleet of 19 E-8 Joint STARS aircraft, which will allow the J-STARS more time on station due to the engine's greater fuel efficiency. NATO also plans to re-engine their fleet of E-3 Sentry AWACS aircraft. The -219 is publicized as being half the cost of the competing 707 re-engine powerplant, the CFM International CFM56, and is 40 dB quieter than JT3D engines that are being replaced.[17]

Operational history

The first commercial orders for the 707 came on October 13, 1955,[18] when Pan Am committed to 20 707s and 25 Douglas DC-8s, a dramatic increase in passenger capacity over its existing fleet of propeller aircraft. The competition between the 707 and Douglas DC-8 was fierce. Several major airlines committed only to the DC-8, as Douglas Aircraft was a more established maker of passenger aircraft at the time. To stay competitive, Boeing made a late and costly decision to redesign and enlarge the 707's wing to help increase range and payload. The new version was numbered 707-320.

Pan Am was the first airline to operate the 707; the aircraft's first commercial flight was from New York to Paris on October 26, 1958 with a fuel stop in Gander, Newfoundland. In December, National Airlines operated the first U.S. domestic jet airline flights between New York/Idlewild and Miami, using 707s leased from Pan Am; American Airlines was the first domestic airline to fly its own jets, on January 25, 1959. TWA started domestic 707-131 flights in March and Continental Airlines started 707-124 flights in June; airlines that had ordered only the DC-8, such as United, Delta, and Eastern, were left without jets until September and lost market share on transcontinental flights. Qantas was the first non-US airline to use the 707s, starting in 1959.

The 707 quickly became the most popular jetliner of its time. Its popularity led to rapid developments in airport terminals, runways, airline catering, baggage handling, reservations systems, and other air transport infrastructure. The advent of the 707 also led to the upgrading of air traffic control systems to prevent interference with military jet operations.[19]

As the 1960s drew to a close, the exponential growth in air travel led to the 707's being a victim of its own success. The 707 was now too small to handle the increased passenger densities on the routes for which it was designed. Stretching the fuselage was not a viable option because the installation of larger, more powerful engines would in turn need a larger undercarriage, which was not feasible given the design's limited ground clearance. Boeing's answer to the problem was the first twin-aisle airliner—the Boeing 747. The 707's first-generation engine technology was also rapidly becoming obsolete in the areas of noise and fuel economy.

In 1982, during the Falklands War the Argentine Air Force extensively used civilian 707s for long-range maritime patrol, with some of them being intercepted and shepherded away by Royal Navy Sea Harriers,[20] it also led to the conversion of British Nimrods to carry Sidewinder air-to-air missiles after a casual encounter.

Trans World Airlines flew the last scheduled 707 flight for passengers by a US carrier on October 30, 1983,[21] although 707s remained in scheduled service by airlines from other nations for much longer. For example, Middle East Airlines (MEA) of Lebanon flew 707s and 720s in front-line passenger service until the end of the 1990s. Since LADE of Argentina took its 707-320B from regular service in 2007, Saha Airlines of Iran is the last airline to keep 707s in scheduled passenger service.

Operations of the 707 were threatened by the enactment of international noise regulations in 1985. Shannon Engineering of Seattle, Washington developed a hush kit with funding from Tracor, Inc, of Austin, Texas. By the late 1980s, 172 Boeing 707s had been equipped with the Quiet 707 package. Boeing acknowledged that more 707s were in service then than before the hush kit was available. Most remaining 707s are in freighter form, or as Business Jets.

Variants

Although certificated as Series 100s, 200s, 300s, etc., the different 707 variants are more commonly known as Series 120s, 220s, 320s, and so on, where the "20" part of the designation is Boeing's "customer number" for its development aircraft.

707-020

The original designation for what ultimately became the Boeing 720. Launch customer United Air Lines was a Douglas DC-8 customer and preferred not to be seen as buying the competing 707 hence the 720 designation. American Airlines always referred to its 720s as 707s.

707-120

The 707-120 was the first production 707 variant, with a longer, wider fuselage, and greater wingspan than the Dash-80. The cabin had a full set of rectangular windows and could seat up to 179 passengers. It was designed for transcontinental routes and often required a refuelling stop on the North Atlantic. It had four Pratt & Whitney JT3C-6 turbojets, civil versions of the military J57, initially producing 13,000 lb (57.8 kN) with water injection. Maximum takeoff weight was 247,000 lb and first flight was on December 20, 1957. Major orders were the launch order for 20 707-121 aircraft by Pan American and an American Airlines order for 30 707-123 aircraft. The first revenue flight was on October 26, 1958.[25] 56 were built, plus 7 short body -138s.

The 707-138 was a -120 with a fuselage ten feet shorter than the others, with 5 feet (3 frames) removed ahead and behind the wing, giving increased range. Maximum take off weight was the same 247,000 lb as the standard version. It was a variant for Qantas and had Boeing customer number 38 for Qantas. A total of 7 -138s were built, first carrying passengers in July 1959.

The 707-120B had Pratt & Whitney JT3D-1 turbofan engines, which were quieter, more powerful, and more fuel-efficient, producing 17,000 lbf (75.6 kN) each, with the later JT3D-3 version giving 18,000 lbf (80 kN). (This thrust did not require water injection, eliminating both the system and the 5000-6000 lb weight of the water itself.) The -120B had the wing modifications introduced on the 720 and a longer tailplane; a total of 72 were built, 31 for American and 41 for TWA, plus 6 short body -138Bs for Qantas. American had its 23 surviving -123s converted to 123Bs but TWA did not convert its 15 -131s. The only other conversions were Pan American's 5 surviving -121s and one surviving -139, the 3 aircraft delivered to the USAF as -153s and the 7 short body Qantas -138s. The first flight of the -120B was on 22 June 1960 and American carried the first passengers in March 1961. Maximum weight was 258,000 lb (117,025 kg) for both the long and short body versions.

707-220

The 707-220 was designed for hot and high operations with more powerful 15,800 lb (70.80 kN) Pratt & Whitney JT4A-3 turbojets. Five of these were produced, but only four were ultimately delivered with one being lost during a test flight. All were for Braniff International Airways and carried the model number 707-227; the first entered service in December 1959. This version was made obsolete by the arrival of the turbofan-powered 707-120B.

707-320

The 707-320 Intercontinental is a stretched version of the turbojet-powered 707-120, initially powered by JT4A-3 or JT4A-5 turbojets producing 15,800 lb (70.1 kN) each (most eventually got 17,500 lb (78.4 kN) JT4A-11s). The interior allowed for up to 189 passengers due to an 80-inch (2,000 mm) fuselage stretch ahead of the wing (from 138 ft 10 in (42.32 m) to 145 ft 6 in), with extensions to both the tail and horizontal stabilizer extending the aircraft's length further. while a longer wing carried more fuel, increasing range by 1,600 miles (2,600 km) and allowing the aircraft to operate as true transoceanic aircraft. The wing modifications included outboard and inboard inserts, as well as a kink in the trailing edge to add area inboard.[13] Takeoff weight was increased to 302,000 lb (137,000 kg) initially, and to 312,000 lb (142,000 kg) with the higher-rated JT4A's and centre section tanks. First flight was on January 11, 1958; 69 turbojet 707-320s were produced, the first passengers being carried (by Pan Am) in August 1959. No -320 Intercontinental models were re-engined with fan engines in civil use, but around year 2000 the Israeli Air Force re-engined two ex-Sabena -320 based military tankers.

707-420

The 707-420 was identical to the -320 but fitted with Rolls Royce Conway 508 turbofans (or by-pass turbojets as they were known at the time). First announced customer was Lufthansa. BOAC's controversial order was announced six months later but the British carrier got the first service-ready aircraft off the production line. The British Air Registration Board refused to give the aircraft a certificate of airworthiness in the form presented, citing insufficient lateral control, excessive rudder forces and the ability to over rotate on take off, stalling the wing on the ground (a fault of the de Havilland Comet 1). Boeing responded by adding 40 inches to the vertical tail, applying full instead of partial rudder boost and fitting an underfin to prevent over rotation. These modifications became standard on all 707 variants and were retrofitted to all previously built aircraft. Only 37 -420s were built, for BOAC, Lufthansa, Air-India, El Al and Varig; Lufthansa was the first to carry passengers, in March 1960.

707-320B

The 707-320B saw the application of the JT3D turbofan to the Intercontinental but with aerodynamic refinements. The wing was modified from the -320 by adding a second inboard kink, a dog-toothed leading edge, and curved low drag wingtips instead of the earlier blunt ones.[13] These new wingtips increased overall wingspan by three feet. Takeoff gross weight was increased to 328,000 lb (149,000 kg). The 175 707-320B aircraft were all new-build; no original -320 models were converted to fan engines in civilian use. First service was June 1962, with Pan Am.

The 707-320B Advanced is an improved version of the -320B, adding the three-section leading-edge flaps already seen on the -320C. These reduced takeoff and landing speeds and altered the lift distribution of the wing, allowing the ventral fin found on earlier 707s to be deleted. From 1965 -320Bs had the uprated -320C undercarriage allowing the same 335,000 lb (152,000 kg) MTOW. These were often identified as 707-320BA-H.

707-320C

The 707-320C has a convertible passenger–freight configuration, which became the most widely produced variant of the 707. The 707-320C added a strengthened floor and a new cargo door to the -320B model. The wing was fitted with three section leading edge flaps which allowed the deletion of the underfin. Three hundred thirty-five of these variants were built, including a small number with JT3D-7 engines (19000 lb takeoff thrust) and a takeoff gross weight of 335,000 lb (152,000 kg). Ironically, most -320Cs were delivered as passenger aircraft, airlines hoping that the cargo door would increase second hand values. The addition of two additional emergency exits, one on either side aft of the wing raised the maximum passenger capacity to a theoretical 219. Only a few aircraft were delivered as pure freighters. One of the final orders was by the Iranian Government for 14 707-3J9C aircraft capable of VIP transportation, communication, and in-flight refuelling tasks.

Other variants

The 707-700 was a test aircraft used to study the feasibility of using CFM International's CFM56 powerplants on a 707 airframe and possibly retrofitting them to existing aircraft. After a testing in 1979, N707QT, the last commercial 707 airframe, was refitted to 707-320C configuration and delivered to the Moroccan Air Force as a tanker aircraft. (This purchase was considered a "civilian" order and not a military one.) Boeing abandoned the program, since it felt it would be a threat to the Boeing 757 program. The information gathered in the test led to the eventual retrofitting program of CFM56 engines to the USAF C-135/KC-135R models, and some military versions of the 707 also used the CFM56. It is ironic that the Douglas DC-8 "Super 70" series by Cammacorp did develop commercially, extending the life of DC-8 airframes in a stricter noise regulatory environment, so there are today more DC-8s in commercial service than there are 707s.

Military

The militaries of the United States and other countries have used the civilian 707 aircraft in a variety of roles, and under different designations. (Note the 707 and U.S. Air Force's KC-135 were developed in parallel from the Boeing 367-80 prototype.)

The Boeing E-3 Sentry is a U.S. military airborne warning and control system (AWACS) aircraft based on the Boeing 707 that provides all-weather surveillance, command, control and communications.

The VC-137C variant of the Stratoliner was a special-purpose design meant to serve as Air Force One, the secure transport for the President of The United States of America. These models were in operational use from 1962 to 1990. The two aircraft remain on display: SAM 26000 is at the National Museum of the United States Air Force near Dayton, Ohio and SAM 27000 is at the Ronald Reagan Presidential Library in Simi Valley, California.

The Canadian Forces also operated Boeing 707 with designation CC-137 Husky (707-347C) from 1972 to 1997.

Boeing 377 Stratocruiser

The Boeing 377, also called the Stratocruiser, was a large long-range airliner built after World War II. It was developed from the C-97 Stratofreighter, a military derivative of the B-29 Superfortress used for troop transport. The Stratocruiser's first flight was on July 8, 1947.

Released in the late 1940s, the aircraft was powered by four piston engines, driving tractor propellers. The aircraft was able to cruise at about 32,000 feet. It also had a pressurized cabin, which was a relatively new feature to transport aircraft at the time, and two decks. Airlines were able to make transoceanic flights easier and faster with the new aircraft, which enabled easier international travel to places such as Hawaii.

Nevertheless, the Stratocruisers did not have great reliability (chiefly due to chronic problems with the extremely complex[citation needed] 28-cylinder R-4360 engines and the associated propellers) and only 56 were built for airlines.

Design and development

Like the C-97, the 377 was developed towards the end of World War II by adapting an enlarged upper fuselage onto the lower fuselage and wings, which were essentially the same as those of the B-50 Superfortress, the high-performance evolution of the B-29 Superfortress bomber. The 377 was larger and longer-ranged than the Lockheed Constellation and Douglas DC-6, with nonstop transatlantic range eastbound. Production ended in 1950.

The "inverted-figure-8" double-deck fuselage design provided 6,600 ft³ (187 m³) of interior space where the lower deck had a smaller diameter than the upper deck. It offered seating for over 100 passengers, or sleeping berths for up to 28 berthed and five seated passengers. It first flew on July 8, 1947. It had the speed and range to span ocean routes, enabling flying from New York to Hawaii in less than 24 hours.[3] Pressurization (previously introduced on the Boeing Stratoliner and also designed into the B-29) allowed sea-level cabin pressure at 15,500 ft (4,700 m) altitude. At 25,000 ft (7,600 m), passengers enjoyed a "cabin altitude" of only 5,500 ft (1,700 m).

Operational history

Despite a service record remembered for one or two early disasters arising from a propeller design fitted to the Stratocruiser in its earlier years, Boeing's remarkable airliner was one of the most capable of post-war propeller-driven transports, and certainly among the most luxurious. Only 55 were built as airliners, joined eventually by the reconditioned prototype to make a total of 56. Another 60 of this general design, with significant engineering differences, were built as C-97 military transports, but the majority were built as KC-97 tankers.

The Stratocruiser flew premier services to Hawaii, across both oceans, and elsewhere in the world. It was one of the few airliners with a double-decker seating arrangement (another was the French Breguet Deux-Ponts) until the 747, though some airlines did have lower-level lounges on their L-1011 Tristar aircraft. The upper deck was for 55-100 passenger seats or 28 sleeper berths, while the lower deck had a lounge and bar. Passengers could walk down and get a drink on the long flights, once the plane levelled off at cruising altitude.[citation needed]

In the early 1960s these planes were starting to become superseded by jets such as the de Havilland Comet, Boeing 707 and Douglas DC-8. A few survived to be sold to smaller airlines, used as freighters or converted into a specialised freighter called a Guppy. As the airlines began to upgrade so did the militaries that were using them. The Boeing 377 was primarily used in only two militaries, the US and Israeli, both of which began buying jet engine aircraft and replacing their 377s.

Boeing 247

The Boeing Model 247 was an early United States airliner, considered the first such aircraft to fully incorporate advances such as all-metal (anodized aluminum) semi-monocoque construction, a fully cantilevered wing and retractable landing gear. Other advanced features included control surface trim tabs, an autopilot and deicing boots for the wings and tailplane.

"Ordered off the drawing board", the 247 first flew on February 8, 1933, and entered service later that year. Subsequently, development in airliner design saw engines and airframes becoming larger, and four-engine designs emerged, but no significant changes to this basic formula appeared until cabin pressurization and high altitude flight were introduced in the early 1940s with the first pressurized airliner, the 307 Stratoliner.

Design and development

Boeing had eclipsed other aviation manufacturers by introducing a host of aerodynamic and technical features into a commercial airliner. This advanced design which was a progression from earlier Monomail (Models 200, 221, 221A) and B-9 bomber designs, combined speed and safety. The Boeing 247 was faster than the U.S. premier fighter aircraft of its day, the Boeing P-12, which was an open-cockpit biplane. Yet its flight envelope included a rather docile 62 mph landing speed which precluded the need for flaps, and pilots learned that at speeds as low as 10 mph, the 247 could be taxiied "tail high" for ease of ground handling.

In addition, the 247 was the first twin-engine passenger transport able to fly on one engine. With controllable pitch propellers (standard equipment on the 247D), the 247 could maintain 11,500 ft at maximum gross takeoff weight.[8] Its combination of features set the standard for the Douglas DC-1 and other airliners before World War II. Originally planned as a 14-passenger airliner powered by Pratt & Whitney R-1690 Hornet radial engines, the preliminary review of the design concept by United Air Lines' pilots had resulted in a re-design to a smaller, less capable design configuration.

One concern of the pilots was that no airfield then in existence, in their view, could safely take an eight-ton aircraft. They also objected to the use of Hornet engines because most pilots were accustomed to the less-powerful Wasps and would find Hornets overpowering. Pratt & Whitney's chief engineer, George Mead, knew that this thinking was misguided and that within a few years would seem antiquated. P&W's president, Frederick Rentschler, faced with a tough decision, decided to acquiesce to the airline pilots' unanimous demand. The decision created a rift between Mead and Rentschler.

Despite the bitter disagreements on design and engines, the 247 was still a remarkable achievement and was Boeing's showcase exhibit at the 1933 Chicago World's Fair.

The cockpit windshield of the first 247s was angled "forward" instead of the conventional aft sweep. This was the design solution (similar to that adopted by other contemporary aircraft that used a forward raked windscreen) to the problem of lighted control panel instruments reflecting off the windshield at night, but it turned out that the forward-sloping windshield would reflect ground lights instead, especially during landings, and it also increased drag slightly. By the introduction of the 247D, the windshield was sloped aft in the usual way, and the night-glare problem was resolved by installing an extension (the glarescreen) over the control panel.

Boeing considered safety features highly, building in structural strength as well as incorporating design elements that enhanced customer comfort and well-being, such as the thermostatically-controlled, air conditioned and sound-proof cabin. The crew included a pilot and co-pilot as well as a flight attendant who could tend to passenger needs. The main landing gear did not fully retract; a portion of the wheels extended below the nacelles, typical of designs of the time, as a means of reducing structural damage in a wheels-up landing. The tailwheel was not retractable. While the Model 247 and 247A had speed-ring engine cowlings and fixed-pitch propellers, the Model 247D incorporated NACA cowlings and variable pitch propellers.

Operational history

Boeing 247D in its MacRobertson Race markings, c. 1934. Note the inaccurate race number and dramatic pose in this fanciful 1935 illustrated card art.

As the 247 emerged from its test and development phase, the company further showcased its capabilities by entering a long-distance air race in 1934, the MacRobertson Race from England to Australia. During the 1930s, aircraft designs were often proven in air races and other aerial contests. A modified 247D was entered, flown by Col.Roscoe Turner and Clyde Pangborn.[17] The 247, race number "57," was essentially a production model but all airliner furnishings were deleted to accommodate additional fuselage fuel tanks (eight in total). The MacRobertson Race attracted aircraft entries from all over the globe including prototypes as well as established production types with the grueling course considered an excellent proving ground as well as an opportunity to gain worldwide attention. Turner and Pangborn came in second place in the transport section (and third overall), behind the Boeing 247's eventual rival, the new Douglas DC-2.

Winner of the 1934 US Collier Trophy for excellence in aviation design, the first 247 production orders were earmarked for William Boeing's airline Boeing Air Transport.

The 247 was capable of crossing the United States from east to west eight hours faster than its predecessors, such as the Ford Trimotor and Curtiss Condor. Entering service on May 22, 1933, a Boeing Air Transport 247 set a cross-country record pace of 19½ hours on its San Francisco to New York inaugural flight.[1] For the first time airline passengers could fly across the country without changing planes or stopping overnight.

Due to the initial demand from U.S. air carriers, Boeing sold the first 60 247s, an unprecedented $3.5 million order to its affiliated airline, Boeing Air Transport (part of the United Aircraft and Transport Corporation, UATC), at a unit price of $65,000. TWA (Transcontinental & Western Air) also ordered the 247 but UATC declined the order, which resulted in TWA President Jack Frye setting out the requirements for a new airliner and funding Don Douglas to design and build the Douglas DC-1 prototype. Douglas eventually developed the design into the historic and enormously successful DC-3 line.

Although the Boeing design had been the first to enter series production, the 247 proved to have some serious design deficiencies. Air carriers considered its limited capacity a drawback since it only carried 10 passengers, in five rows with a seat on each side of the aisle, as well as a flight attendant. Compared to the more capacious DC-2 and later DC-3, the passenger count was too few to make it a commercially viable airliner. Another feature influencing passenger comfort was that the 247's main wing spar ran through the cabin, so persons moving through the cabin had to step over it. The Lockheed Model 10 Electra had a similar configuration and while it was a more compact design, the Electra managed to carry the same number of passengers at a slightly better overall performance, and more importantly, at a lower cost-per-mile.

Seventy-five 247s were built; by contrast, Douglas collected 800 civil orders for DC-3s before the Pearl Harbor attack, and produced over 10,000 DC-3s, including wartime production of C-47; while the rival Lockheed Electra "family" was eventually to reach over 3,000 in its various civilian and military variants. Boeing Air Transport bought 60 examples, United Aircraft Corp. (10), four went to Deutsche Luft Hansa, and one a private owner in China. While the industry primarily standardized on Boeing's competitors, many of United's aircraft were later purchased by Western Air Express at "bargain basement prices".

The 247 remained in airline service until World War II, when several were converted into C-73 transports and trainers. No. 121 Squadron, Royal Canadian Air Force (RCAF) operated seven Model 247Ds as medium transports during the early part of the war. Some 247s were still flying in the late 1960s, converted either into cargo transports or personal business aircraft.

A number of specially modified variants included a Boeing 247Y appropriated from United for Air Corps use as a test aircraft fitted with two machine guns in the nose. The same installation later was fitted to a 247Y owned by Generalissimo Chiang Kai-Shek; this aircraft also featured a Colt .50 caliber machine gun in a flexible mount. A 247D purchased by the British Royal Air Force became a test mule for new equipment, featuring a nonstandard nose, new powerplants and non-retracting gear.

The Turner/Pangborn 247D still exists. Originally flown on September 5, 1934, it was leased from United Airlines for the 1934 MacRobertson Race and returned to United where it served in regular airline service until 1937. Subsequently, the 247D was sold to the Union Electric Company of St. Louis for use as an executive transport. The Air Safety Board purchased the aircraft in 1939 and it remained in use for 14 years before it was donated to the National Air and Space Museum, Washington, DC. It is displayed today with two sets of markings, the left side is marked as NR257Y, in Colonel Turner's 1934 MacRobertson Race colors, while the right side is painted in United Airlines livery, as NC13369.

Boeing Model 1

The Boeing Model 1, also known as the B & W Seaplane, was a United States single-engine biplane seaplane aircraft. It was the first Boeing product and carried the initials of its designers, William Boeing and Lt. Conrad Westervelt USN.

The first B & W was completed in June 1916 at Boeing's boathouse hangar on Lake Union in Seattle, Washington. It was made of wood, with wire bracing, and was linen-covered. It was similar to the Martin trainer aircraft that Boeing owned, but the B & W had better pontoons and a more powerful engine. The first B & W was named Bluebill, and the second was named Mallard. They first flew on 15 June 1916, and in November, respectively.


The two B & Ws were offered to the United States Navy. When the Navy did not buy them, they were sold to the New Zealand Flying School and became the company's first international sale. On June 25, 1919 the B&W set a New Zealand altitude record of 6,500 feet. The B & Ws were later used for express and airmail deliveries, making New Zealand's first official airmail flight on December 16, 1919.