Amazing Aircraft: The Baby Boeing, 50 Years in the Making

On April 9, 1967, 50 years ago today, one of the most popular airliners in the world, the Boeing 737 made it's first flight. If you've flown commercial before on a domestic or even a short international flight, chances are very likely that you flew on the Boeing 737 on a few occasions during your travels! A popular, reliable, and versatile workhorse with airlines all over the world, the 737 family has evolved into over ten different variants since the initial introduction 50 years ago.

Originally envisioned as a short- to medium-range twinjet narrow-body airliner (a regional jet by today's standards) to be operated as a shorter, lower-cost twin-engine airliner derived from Boeing's 707 and 727, the 737 has surpassed original expectations as the latest models are able to fly transcontinental and even some transoceanic or partial transoceanic routes. It has revolutionized commercial air travel by transforming the economics of domestic air travel. It's a smaller jet airliner, so that meant quicker turnaround times on the ground in between flights. It also had greater fuel efficiency and the ability to operate from smaller or secondary airports led to the concept of low-cost carriers, which ultimately brought air travel to the masses whereas before, air travel was for the elite and affluent. The "Baby Boeing" as it became known, has even begun replacing Boeing's larger line-up of jetliners such as the 757 in some areas.

To date, Boeing has manufactured well over 9,000 airframes of all 737 variants, with over 4,000 orders worldwide that have yet to be fulfilled. Since 2006, there is an average of 1,250 Boeing 737s airborne somewhere in the world at any given time, with two planes departing or landing somewhere every five seconds, making it the best-selling commercial jet airliner in history. These statistics stand as a testament to how popular and reliable the Boeing 737 is throughout the world. Manufacturing of the 737 takes place at Boeing's Renton factory in Renton, Washington, just outside of Seattle. Competition for the 737 comes primarily from Airbus with their A320 family.

The Boeing 737 family can be split up into four generations:

• Boeing 737 Original series
• Boeing 737 Classic
• Boeing 737 Next Generation (737NG)
• Boeing 737 MAX

Boeing 737 Original Series

First generation 737s consists mainly of the 737-100 and 737-200, with the latter receiving subtle updates to become the 737-200/Advanced. 

The initial model, the 737-100 was rolled out on January 17, 1967 and first flew on April 9, 1967, 50 years ago today. Only 30 737-100s were ordered and delivered, with the launch customer being Lufthansa, which entered service on February 10, 1968. The original, prototype 737-100 (pictured above) last operated by NASA is now on permanent display in its hometown of Seattle, Washington at the Museum of Flight.

The very first 737 ever built by Boeing, a 737-100 (N515NA) on display at the Museum of Flight in Seattle, WA. This prototype airframe kick-started one of the most successful commercial jet airliners in history!

The 737-200 is a stretched version of the original -100 and was rolled out on June 29, 1967, and entered service with launch customer United Airlines in April 1968. An improved version, the 737-200/Advanced entered service with Japanese carrier, All Nippon Airways on May 20, 1971. The 737-200/Advanced has improved aerodynamics, automatic wheel brakes, more powerful engines, and more fuel capacity, which results in longer range than the 737-100. Boeing also offered the 737-200C (Cargo), which allowed for conversion between passenger and cargo use and the 737-200QC (Quick Change), which facilitated a rapid conversion between both passenger and cargo roles. As of today, there are still a handful of 737-200s still in service, mainly with "second and third tier" airlines as well as those of developing nations. Airlines operating the 737-200 also had the option to install gravelkit modifications, which allowed them use of unimproved or unpaved landing strips, such as gravel runways, that other similarly-sized jet aircraft could not operate from. Gravelkit-equipped 737s revealed just how reliably-versatile the aircraft-type could be. The now-defunct Aloha Airlines was the last U.S. operator of the original series of the 737 to carry passengers, which occurred in March 2008.

Another variant of the 737-200 came in the form of the T-43A, a United States Air Force trainer designed to train aircraft navigators. Nineteen 737-200 airframes were used in this role. Some T-43s were modified into the CT-43A, a VIP passenger transport, and one airframe was modified as the NT-43A Radar Test Bed aircraft.

Boeing 737-200 used as a ground trainer for aspiring aviation students at Purdue University.

Boeing 737 Classic Series

Second generation 737s include the 737-300, 737-400, and 737-500. Originally introduced as the 'new generation' of the 737, 1,988 aircraft were delivered, produced between 1984 to 2000. The "Classic" name was an aftermarket name given after Boeing introduced the 737NG (-600, -700, -800, -900). The 737 Classic series had features increase in capacity and range and incorporated improvements to upgrade the type to modern specifications, while also retaining commonality with previous 737 variants.

The 737-300 prototype rolled out of the Boeing Renton plant on January 17, 1984, and first flew on February 24, 1984. It was certified by the FAA on November 14, 1984, and USAir received the first aircraft on November 28 that same year. The 737-300 remained in production until 1999 and over 1,000 airframes were produced. They were also able to receive aftermarket winglets made and installed by Aviation Partners, which changed the aircraft's designation to the 737-300SP. Many second-hand 737-300s have also found a second lease in their service life by being converted into freighters.

Boeing 737-300 operated by Southwest Airlines in the Canyon Blue livery. Southwest is the world's largest operator of the 737 with well over 700 aircraft in it's fleet, each averaging six flights a day. The airline plans to phase out the 737-300 from its fleet by September 30, 2017.

Boeing 737-300 operated by Southwest Airlines in the Arizona One livery.

Boeing 737-300 operated by Southwest Airlines in the Heart livery.

The 737-400, launched in 1985 was designed to fill and serve a market gap between those that of a 737-300 and 757-200; in other words, to serve markets that were beyond the capabilities of a 737-300 but too thin for the 757-200. It is 10 feet longer than a 737-300 and can carry up to 188 passengers. The 737-400 features a tail bumper to prevent tailscrapes during take-off (an early issue that the 757 also experienced), and a strengthened wing spar. The first one built was rolled out on January 26, 1988, and first flew on February 19, 1988. The 737-400 entered service on September 15, 1988 with now-defunct launch customer, Piedmont Airlines. The 737-400 directly competes with the Airbus A320 and the McDonnell Douglas MD-80 family. 

Some 737-400s also saw service as aftermarket converted freighters, designated as the 737-400F. Boeing never offered the 737-400 as a freighter direct from the factory. Alaska Airlines was the first airline to convert their 737-400s into 737-400Fs, capable of handling ten pallet loads. Alaska Airlines also converted several of their 737-400s into fixed combi (short for combination) aircraft for half passenger and freight.

Boeing 737-400 operated by Alaska Airlines.

Boeing 737-400 operated by Xtra Airways.

Boeing 737-400 operated by Alaska Airlines in the Spirit of Make-A-Wish livery.

The 737-500 was a result of customer demand for a modern and direct replacement of the 737-200. About a foot and a half longer than the 737-200 and able to accommodate up to 140 seats, the 737-500 features improvements that allowed flights for longer routes with fewer passengers, making it far more economical than with the 737-300. In a 737-500 Boeing offered cockpits with either the classic steam gauges or a glass cockpit. It was launched by Southwest Airlines in 1987 and first flew on June 30, 1989. Southwest received their first 737-500 on February 28, 1990. Interestingly, the 737-500 has become a favorite of several Russian carriers, including Nordavia, Rossiya Airlines, S7 Airlines, Sky Express, Transaero, UTair and Yamal Airlines all buying them second-hand to replace aging Soviet-built aircraft and/or expand their fleets. Southwest Airlines flew their last 737-500 revenue flight on September 5, 2016.

Boeing 737-500 operated by Hokkaido International Airlines.

Boeing 737-500 operated by ANA Wings.

Boeing 737NG Next Generation

Third generation 737s include the 737-600, 737-700, 737-800, and 737-900. The 737NG series resulted in the early 1990s when the Airbus A320 family won over previously loyal 737 customers such as Lufthansa and United Airlines, which posed a serious threat to Boeing's market share. The 737NG serves as a direct replacement for the 737 Classic series

The 737-600 serves as a direct replacement for the 737-500 and competes with the Airbus A318 (Babybus). The launch customer was Scandinavian Airlines (SAS) when they placed orders in 1995 with the first aircraft delivered on September 18, 1998. Only 69 737-600s were built amid poor sales. As of 2012, Boeing has removed the 737-600 from their line-up of aircraft.

The 737-700 is considered to be the true first variant of the 737NG family. Southwest became the launch customer in November 1993 and entered service in 1998. It is a direct replacement for the 737-300 and competes with the Airbus A319. The 737-700 seats 137 passengers in a two-class cabin or 149 in all-economy configuration. Boeing also offers the Boeing 737-700C, which is a convertible version of the type where the seats can be removed to carry cargo instead, featuring a large cargo door on the left side of the aircraft. The United States Navy was the launch customer for the 737-700C designated the C-40A Clipper. The United States Air Force operates the C-40B and C-40C to transport military leaders, as well as government VIPs. Air Force-operated C-40 Clippers have sometimes transported the Vice President of the United States under the callsign "Air Force Two."

One January 31, 2006, Boeing launched the 737-700ER with All Nippon Airways being the launch customer. It is a mainline passenger version of the Boeing Business Jet BBJ1 and 737-700IGW, which combines a standard 737-700 fuselage with wings and landing gear of a 737-800. Designed for long-range commercial operations the 737-700ER is capable of flying a range of 5,510 nautical miles and can seat 126 passengers in a traditional two-class configuration. All Nippon Airways used the 737-700ER on daily service between Tokyo and Mumbai from 2007 until April 2016; it is believed to be the first all-business class route connecting to a developing country.

A military variant of the 737-700ER is the the 737 AEW&C (Airborne Early Warning and Control). The Australian Air Force was the launch customer of the type under the name "Project Wedgetail and designated E-7A Wedgetail. The 737 AEW&C is also currently in service with the  Turkish Air Force (under "Project Peace Eagle") and the Republic of Korea Air Force ("Project Peace Eye")

Boeing 737-700 operated by Southwest Airlines in the Canyon Blue livery. In addition to being the largest operator of the 737, Southwest also operates the largest fleet of 737-700s, with nearly 500 in its current fleet. 

Boeing 737-700 operated by Sun Country Airlines.

Boeing 737-700 operated by Alaska Airlines in the Portland Timbers livery.

Boeing 737-700 operated by United Airlines.

Boeing 737-700 operated by Alaska Airlines.

Boeing 737-700 operated by Southwest Airlines in the Heart livery.

Boeing 737-700 operated by Southwest Airlines in the original Desert Sand retro livery.

The 737-800 serves as a direct replacement for the 737-400 and fills the gap left by Boeing following the company's the decision to discontinue the McDonnell Douglas MD-80 and MD-90 following Boeing/McDonnell Douglas merger. From a business perspective, it makes sense because the 737-800 is more fuel efficient and has greater range compared to the MD-80 and MD-90. For many U.S. carriers, the 737-800 also served as a replacement for the 727-200 trijet. Hapag-Lloyd Flug (predecessor airline to what we now know as TUIfly) became the launch customer for the 737-800 in 1994 and entered service in 1998. Boeing also launched the 737-800BCF (Boeing Converted Freighter) passenger to freighter conversion program in February 2016; to date, there currently over 50 conversion orders with the first delivery expected in late 2017. Ryanair is currently the largest operator of the 737-800, with over 300 airframes in operation.

A military variant of the 737-800 is designated as the P-8 Poseidon, used for anti-submarine warfare. Development began following a selection process on June 14, 2004 to replace the Lockheed P-3 Orion maritime patrol aircraft. Designated by Boeing as the 737-800A, the P-8 Poseidon features raked wingtips instead of the blended wingtips commonly found on the airliner variants. Current operators of the sub-hunting 737-800 include the United States Navy, Indian Navy (designated as the P-8I Neptune), and the Royal Australian Air Force with the U.K. Royal Air Force and Norwegian Air Force both having placed orders.

Boeing 737-800 operated by Eastern Air Lines.

Boeing 737-800 operated by Alaska Airlines in the retro Starliner 75 livery.

Boeing 737-800 operated by American Airlines in the new livery.

Boeing 737-800 operated by Southwest Airlines in the Heart livery.

Boeing 737-800 operated by Alaska Airlines in the Adventure of Disneyland Resort livery.

Boeing 737-800 operated by Shanghai Airlines.

Boeing 737-800 operated by Delta Air Lines.

Boeing 737-800 operated by Alaska Airlines in the hybrid Boeing livery dubbed the Spirit of Seattle.

Boeing 737-800 operated by United Airlines.

Boeing 737-800 operated by Sun Country Airlines.

Boeing 737-800 operated by Alaska Airlines in the Spirit of the Islands livery.

Boeing 737-800 operated by American Airlines in the classic metal finish livery.

Boeing 737-800 operated by Southwest Airlines in the Canyon Blue livery.

Boeing 737-800 operated by Delta Air Lines in SkyTeam colors.

The 737-900 is the longest operational variant of the 737 family to date. Alaska Airlines became the launch customer in 1997 and took delivery of its first 737-900 on May 15, 2001. It retains the same exit configuration of the 737-800, so seating capacity was in a high-density single class layout was limited to 189 seats, but a two-class layout was higher at around 177 seats. The 737-900 sacrificed range for a higher payload, therefore retaining the same maximum takeoff weight and fuel capacity of the 737-800, creating shortcomings that prevented it from effectively competing with the Airbus A321.

Boeing 737-900 operated by launch customer Alaska Airlines.

The Boeing 737-900/ER closed the gaps and resolved the shortcomings of the base model 737-900. Rolled out on August 8, 2006 for launch customer Lion Air, the 737-900/ER has a comparable range and passenger capacity to the 757-200 (which Boeing discontinued in favor of the larger 737 variants) and competes directly the Airbus A321. The 737-900/ER features an additional pair of exit doors, a flat rear pressure bulkhead, increased seating capacity to 180 passengers in a two-class configuration or 220 seats in a single-class layout, additional fuel capacity, and standard winglets that helped to improve range comparable the shorter 737NG variants.

Boeing 737-900/ER operated by United Airlines.

Boeing 737-900/ER operated by Delta Airlines.

Boeing 737-900/ER operated by Alaska Airlines.

Boeing Business Jet (BBJ)

The Boeing Business Jet name typically refers to every size variant of Boeing jet airliners for the corporate jet market. But the Boeing Business Jet is traditionally based off the 737NG models with the BBJ/BBJ1, BBJ2, and BBJ3 being based off the 737-700, 737-800, and 737-900/ER variants respectively. While similar externally to the airliner models they're based off of, the Boeing Business Jets typically come with additional custom features, depending on what owners/operators desire; examples of such features include blended winglets for fuel economy and increased range, self-contained air stairs to allow disembarking at airports with limited ground support (and showing off how versatile the 737 can really be!), additional fuel tanks, and certification to fly under the ETOPS 180 minute rule (flying to a diversion airport within 3 hours in the event of one engine failing during flight over remote areas). Following the launch of the BBJ series, Airbus launched a similar program called the Airbus Corporate Jets (ACJ) derived from the A319/A320 family. In addition to Airbus, the BBJ competes with the Embraer Lineage, the Bombardier Global Express, the Gulfstream G550 and the Gulfstream G650.

The first Boeing Business Jet rolled out on August 11, 1998 and first flew on September 4 later that same year. Boeing then launched the BBJ2 on October 11, 1999 and made the first delivery on February 28, 2001. The first BBJ3 was built in August 2008. And now with the advent of the 737 MAX series, Boeing is proposing a fourth-generation BBJ variant.

Boeing 737-700 BBJ operated by a private owner. If you've got several million dollars in the bank account to spare and you want to travel in luxury, the Boeing Business Jet might be just for you!

Boeing 737 MAX

Announced by Boeing in 2011, the 737 MAX series is the fourth generation of the 737 family and will be initially offered in three variants: the 737 MAX 7, 737 MAX 8, and 737 MAX 9, respectively replacing the the 737-700, 737-800 and 737-900. To date, Boeing is studying the possibilities of further modifications to the 737 MAX series such as a 737 MAX 10 model. The MAX series will feature a pair of CFM International LEAP-1B engines as the powerplant, the addition of fly-by-wire control to the spoilers, and the lengthening of the nose landing gear. Southwest Airlines became the launch customer for the 737 MAX (with orders for the MAX 7s and MAX 8s specifically) on December 13, 2011. European low-cost carriers Ryanair and Norwegian Air Shuttle have also placed firm orders for the 737 MAX.

The 737 MAX 8 is the first variant developed in the 737 MAX family and will replace the 737-800. The very first one built, nicknamed "Spirit of Renton" was rolled out on December 8, 2015 and first flew on January 29, 2016. FAA certification of the MAX 8 occurred on March 9, 2017. Boeing intends to give the MAX 8 an initial range of 3,515 nautical miles and upgrade it up to 3,610 nautical miles some time after 2021. Entry into service for the 737 MAX 8 is expected to be during the second quarter of 2017 with Malaysian carrier, Malindo Airways.

Boeing launched a high density version of the Boeing 737 MAX 8 known as the MAX 200 in September 2014. The "MAX 200" denotes seating for up to 200 passengers in a single-class high-density configuration with slimline seats. As a result, an extra exit door will be required because of the higher passenger capacity. European low-cost carrier Ryanair was the launch customer for the 737 MAX 200 after ordering 100 airframes.

The shorter 737 MAX 7 is derived from the base model MAX 8 with some redesigns featured. As a direct replacement for the 737-700, it will feature two more rows of seats for a total of 138 seats. It will use the same wings and landing gears found on the 737 MAX 8. The 737 MAX 7 will also feature a pair of overwing exits instead of a single-door configuration found on the 737-700. The MAX 7 will also be longer in fuselage length compared to the 737-700, so it will require structural re-gauging and strengthening as well as systems and interior modifications to accommodate the longer length. The 737 MAX 7 will initially have a range of 3,850 nautical miles, with Boeing hoping to raise the bar up to nearly 4,000 nautical miles some time after 2021. Rollout and first flight dates of for the 737 MAX 7 are yet to be determined.

The 737 MAX 9 rolled out one month ago on March 7, 2017 and Boeing is expecting an inaugural flight some time this month in April. As a direct replacement of the 737-900, it will have an effective range of 3,510 nautical miles with Boeing hoping to increase it up to 3,605 nautical miles some time after 2021. Indonesian low-cost carrier Lion Air became the launch customer of the 737 MAX 9 for an order of 201 airframes in February 2012.

On this momentous landmark year following 50 years in the making, let's wish the 737 a happy birthday! And let's congratulate Boeing for 50 years of success with the "Baby Boeing" that's all grown up!  It has served billions of passengers worldwide as one of the most reliable workhorses in aviation history. May it continue to serve the flying public well in the many decades to come!