Many of you mentioned that you enjoyed my article about the sawing/barking sound heard aboard the Airbus A320, and asked me for more educational articles of a similar style. I’ve been repeatedly asked recently to help deconstruct the various commercial aircraft models over the years produced by Boeing Commercial Airplanes. As a result, I’ve spent a few days preparing this article to help better explain the lineage and connections between the various aircraft Boeing has manufactured over the years. The article is a little longer than usual, but has been written in a style that should allow you to skip around to the parts that interest you quickly. You can read through normally, or simply scroll down to the image of the aircraft you are interested in and read those sections.
NOTE: This article is purely topical, and does not specifically drill down to every single nuance of each aircraft type. If you are looking for more details, I have hot-linked each aircraft type to its corresponding Wikipedia article in BOLD. Also, due to the complexity of the 737 lineup, I may consider “drilling down” in a later article to address those differences at a deeper level.
The Boeing 707 Prototype
The Boeing 707: It all started with Boeing’s 367-80 (known simply as the “Dash 80″), which was quickly developed from the proof-of-concept design to the slightly larger 707. As pictured here, the Boeing 707 was a four-engined narowbody aircraft whose direct competition at the time was the Douglas DC-8. The 707 was the aircraft that began Boeing’s famous 7X7 numbering scheme. This revolutionary aircraft was Boeing’s answer to the “jet age,” and was actually birthed from the US Air Force’s request for a jet-powered mid-air refueling aircraft to replace its slow piston-powered KC-97 fleet. The 707′s first orders came in 1955 from Pan Am, who ordered 20 of the aircraft (a large aircraft order for the era). The 707 flew in US commercial airline service until 1983, having been replaced by a wide variety of aircraft developed to respond to the demand the 707 created. While the Boeing 707 was not the first jet airliner to fly worldwide, it was the most successful of the early jets. Of the 855 built, 151 are still active (mostly US Air Force KC-135s). The 707 was so successful, that it helped the airlines who flew it become more intelligent about streamlining their route structure to take advantage of multiple-sized population centers of which the 707 was not capable of serving. In many cases, it was learned through trial and error that while impressive, the 707 was not a one-size-fits-all airplane. NO LONGER IN PRODUCTION.
Though the Boeing 717 naming scheme was eventually given to the McDonnell-Douglas MD-90 after Boeing acquired the company, the 717 designation was actually used to refer to the stratotanker version of the 707 (military mid-air refuler still in use today). This is why many begin to get confused as to which aircraft came after the 707, etc. Because the later Boeing 717 was ultimately a McDonnell-Douglas aircraft, I have elected not to cover it in-depth within this article.
The Boeing 727 Prototype
The Boeing 727 is perhaps one of the most versatile commercial jet aircraft ever built, and while it does share some limited commonality with the 707, the 727 was a departure from the 707. The 727 boasted a 3 engine rear-mounted T-tailed configuration along with one of the most complex wing flap systems ever developed. The major airlines of the time (American, United and Eastern) all approached Boeing looking for an aircraft that was capable of operating from fields smaller than the 707 was designed for. American wanted a twin-jet design not unlike the Douglas DC-9, United wanted a four-engined design, and Eastern wanted the best of both worlds. Eventually the three settled on a compromise for a three-engined jet and the 727 was born. Seating anywhere from 149 to 189 passengers per aircraft, the 727 was enormously successful and became the mainstay of many airline’s fleets for decades even after production was halted in 1984. NO LONGER IN PRODUCTION.
The Boeing 737 Prototype
The Boeing 737: Now enter the most popular aircraft ever built–the Boeing 737. In fact, if the entire production line of the 727 is considered, the 737 may actually take the 727′s title as the most versatile series of commercial jets built. Developed at almost the same time as the 727, the 737 was originally designed to support short-range low-yield route structures. As a twin-engined jet with a then-unheard-of flight crew of only two, the 737 was seen as a money maker and money saver by airline managers, and a threat by pilots who were used to the three-crew layouts of other aircraft. Lufthansa launched the design with an order for 22 of the 85-124 seat (depending on cabin configuration) 737-100 design. Shortly thereafter United placed an order for 40 stretched 737-100s, which became known as the 737-200. Boeing improved upon the 737-200 design in 1971, which they called the 737-200 Advanced. The -200 Advanced series had improved aerodynamics, automatic wheel brakes, more powerful engines, more fuel capacity, and longer range than the original stretched -200s. Despite the success of the 737 program today, initially the 737 was plagued by slow sales after the early initial interest died down. In 1970 Boeing received only 37 orders for the -200, which was seen as the proverbial “writing on the wall” to initiate development of a more competitive product. BOEING 737-100/200 NO LONGER IN PRODUCTION.
The Boeing 737-300 Prototype
Boeing’s answer to the slump in sales was essentially a refined, re-engine version of the 737-200. The most notable feature of the then-new 737-300 (and later -400, -500 aircraft) is the large and flat-bottom-shaped CFM-56 high-bypass turbofans. These engines along with other less-noticeable refinements in the aircraft allowed the 737-300/400/500 series to burn less fuel than the -200, while providing greater thrust and better overall performance. The 737-300 was launched n 1981 and originally introduced as the “new generation” of the 737 (which is confusing today as the same original name was eventually given to the following version of 737s made available in the 1990s). Today the 737-300, -400 and -500 series are referred to as the “737 Classics,” while the 737-100 and -200 series called the “737 Original.” Some jokingly call the 737-100/200 the “737 Jurassics,” but that nickname is applied only in jest. BOEING 737-300/400/500 NO LONGER IN PRODUCTION.
Boeing later refined the 737 Classics with a new variant of the series, and called it the “New Generation” or “NG” for short. Instead of adding an NG to the end of the 737-300/400/500 series, Boeing opted to give these refined 737s new dash numbers. This resulted in the development of the 737-600, -700, -800, and eventually -900 NG series. The NG 737 was a response by Boeing to address the serious threat that Airbus’ A320 product family presented to the 737 lineup. As a result, Boeing kept many cockpit commonalities with the 737 Classic series in order to retain the common type certificate for pilots, but essentially re-designed this version of the 737 to compete toe-to-toe with Airbus’ A320-family. BOEING 737-600/700/800/900 IN PRODUCTION.
The Boeing 737 Family (up to the New Generation)
The Boeing 737-MAX7 (artistic illustration)
Announced in July this year, Boeing has agreed to continue the 737 for at least another generation with the announcement of the 737 MAX. The 737 MAX is a further refinement of the “New Generation” series of aircraft, primarily incorporating new more fuel-efficient CFM Leap 1B engines as well as aerodynamic changes to improve the aircraft’s performance. Despite being announced less than 6 months ago, Boeing has secured orders for well over 900+ 737MAX series supporting the worldwide demand for improved technology to better mitigate the rising costs of fuel. BOEING 737MAX PRODUCTION PLANNED.
The multiple versions of the 737 have been largely responsible for confusion where replacement models are concerned. To simplify this, I will plan on detailing this particular family of Boeing aircraft in a future article. In the meantime, here’s a quick cheat-sheet to help break down how the various versions of the 737 have replaced each other over the years.
- 737-100 … replaced by … 737-200
- 737-200 … replaced by … 737-300/400/500 Classic; later replaced by the 737-600/700/800NG
- 737-600 … replaced by … no direct replacement planned
- 737-700/800/900 … replaced by … 737-MAX7/MAX8/MAX9
The Boeing 747 Prototype
The Boeing 747: The success of the Boeing 707 in commercial service led Pan Am to conclude that a much larger aircraft was needed to support the anticipated growth expected worldwide. Pan Am was right. The famous Boeing 747 “Jumbo Jet” was developed shortly after the 707, and was two-and-a-half times larger. First commercially flown in 1970, the 747 was the largest commercial jet aircraft in service until it was usurped by Airbus’ massive A380 Super Jumbo. The 747 was originally built to carry 366-452 passengers 5,300 nautical miles at a blistering 84% of Mach 1 (the speed of sound). The “Jumbo Jet” is most characteristically known for its double-decker “hump” at the front of the aircraft. Since entry in to service in the early 1970s, the 747 has seen a number of upgrades/modifications from the 747-100 to the latest model, the 747-8. BOEING 747-8 IN PRODUCTION.
The Boeing 757 and 767 Prototypes
The Boeing 757 and 767: Following the early 737, Boeing electred to refine the product family through the joint-development of the 757 and 767 at the same time. Unlike any previous aircraft developed before by Boeing, the 757 and 767 were designed to share an identical cockpit and type rating. The 757 was designed as a powerful replacement for Boeing’s 727, with a still-unmatched power to weight ratio. Due to the mission profile of the aircraft, Boeing designed the 757 with the same fuselage cross-section as the 707, 727, and 737 family of jets but stretched it to seat anywhere between 186-289 passengers depending on configuration. The 767 was Boeing’s first twin-engined widebody jetliner, built to fly 181 to 375 people anywhere from 3,800 to 6,300 nautical miles depending on configuration and loading. Production of the 757 ceased in 2004, however the 767 is still available for orders. BOEING 757 NO LONGER IN PRODUCTION, BOEING 767 IN PRODUCTION.
The Boeing 777
The Boeing 777 or “triple seven” as she is known, is a long-range widebody jet built to fulfill a different profile than the 767 or 747. Unlike the four-engined 747, the 777 takes advantage of improvements in reliability and technology to give airlines access to the significant cost savings expected from a twin-engined jet, while also merging these capabilities with those formerly expected of a 4-engined aircraft. On the surface, the 777 looks like just another twin-widebody, but the reality is that the 777 was both a game-changer and a sign of growth away from massive 4-engined long-haul airliners to more operationally-sensible twin-engined designs. The twin-engined layout of the aircraft is cheaper to own, cheaper to maintain, and cheaper to operate. Since the first aircraft were delivered in 1995, well over 1,300 aircraft have been ordered and the aircraft is still selling strong. BOEING 777 IN PRODUCTION.
The Boeing 787
The Boeing 787 is the manufacturer’s most technologically advanced commercial aircraft ever constructed. From the outside the aircraft looks similar to many other older commercial aircraft models, but that is where the similarities end. Unlike almost all commercial aircraft before it, the 787 has been largely manufactured from composite materials, nose-to-tail. In addition, where most commercial aircraft are internally pressurized to an elevation of roughly 8,000′, the 787 is pressurized to 6,000′. It has a more humid atmosphere and larger, electronically dimmed windows amongst other passenger-focused amenities. Most importantly, the aircraft allows airlines to finally utilize a long-range fuel-efficient airliner for medium-density routes, such as Houst0n-Auckland (Continental, now United) or Tokyo-San Jose, CA (ANA). BOEING 787 IN PRODUCTION.
Boeing’s commercial aircraft lineup today consists of the Boeing 737 New Generation, the future Boeing 737MAX, the Boeing 747-8, the Boeing 767, the Boeing 777 and the Boeing 787. It can be said that Boeing has a knack for developing well-engineered aircraft, as only 3 commercial aircraft types within Boeing’s original lineup since the 707 are out of production (707, 727, and 757). The Boeing 707 was replaced with more efficient airliners better suited to specific mission profiles. The Boeing 727 was replaced by later versions of the entire 737 family, including the 737-200 and 737 classics. The Boeing 757 was replaced (in range and seating) by the massively-stretched Boeing 737-900ER series—though the B739ER doesn’t have the 757′s famous hot-and-high power-to-weight ratios. The Boeing 737, 747, 767, 777, and 787 families are all still in production in various forms and options as of December 2011.
Boeing's simplified future product portfolio
Going forward, the trend at Boeing is relatively straight-forward. The manufacturer has reached the point where they feel that a simplified product offering is the best way to proceed. Towards that effort, Boeing has been steadily condensing its product family and replacing products where more recent and simplified offerings overlap in capability. An example of this strategy is the replacement of the 757 line with the similarly-capable 737-900ER. In the future, it is expected that the 767 will be the next product line retired leaving the multiple variations of the 737, 747, 777, and 787 available for future customers.
Should you have any questions or comments, don’t hesitate to contact me or reply directly to this article via the form below. Suggestions for future articles are always welcome.
