The Boeing 737 is an American short to medium range, single aisle, narrow body jet airliner. Developed from Boeing's 727 and 707, the 737 is now available in a number of versions, from the -200 to the most recent addition, the -900ER.

First envisioned in 1964, the 737 entered service in 1968, and 25 years after the announcement of its first sale, became the most ordered and produced commercial passenger jet. Continuously manufactured by Boeing since 1967 with over 7,000 ordered and over 5,000 delivered (as of 2007), there are over 1,250 of the type airborne at any given time.(On average, a 737 departs or lands somewhere every five seconds).

Development

Origins
The 737 was born out of Boeing's need to introduce a competitor in the short-range, small capacity jetliner market which had been pioneered by the Sud Aviation Caravelle. Preliminary design work began on 11 May 1964, and Boeing's intense market research yielded plans for a 50 to 60 passenger plane for routes 50 to 1,000 mi (80 to 1,609 km) long. Lufthansa became the launch customer on 19 February 1965, with an order of 21 aircraft after the airline reportedly received assurances from Boeing that the 737 project would not be cancelled. Consultation with Lufthansa over the previous winter resulted in an increase in capacity to 100 seats.

On 5 April 1965, Boeing announced an order by United Airlines for 40 737s. They wanted a larger airplane; therefore, Boeing stretched the fuselage an extra 91 cm (36 in) ahead of, and 102 cm (40 in) behind the wing. The longer version was labeled 737-200, and the original now given the designation 737-100.

Detailed design work continued on both variants at the same time. Boeing was far behind its competitors when the 737 was launched, as rival aircraft BAC 1-11 and Douglas DC-9 were already into flight certification. To expedite development, Boeing reused 60% of the structure and systems of the existing 727, most notably the fuselage cross section. This fuselage permitted six-abreast seating compared to the rival 1-11 and DC-9's five-abreast layout, but the widened cross-section and short fuselage complicated the aerodynamics of the aft-mounted engines common with airliners of the time. As a result, engineers decided to mount the nacelles directly to the underside of the wings. The placement of this weight below the center of the aircraft also reduced stresses on the airframe, which allowed for a lighter wing, and kept the aircraft low to the ground for easy ramp operations. The engine chosen was the Pratt & Whitney JT8D-1 low-bypass ratio turbofan engine. With the wing-mounted engines, Boeing decided to mount the elevator on the fuselage rather than the T-tail style of the Boeing 727.

The initial assembly of the 737 was adjacent to Boeing Field (now officially called King County International Airport) because the factory in Renton was at capacity building the 707 and 727. After 271 aircraft, production was moved to Renton in late 1970. A significant portion of the fuselage assembly is in Wichita, Kansas previously by Boeing but now by Spirit AeroSystems, which purchased some of Boeing's assets in Wichita. The fuselage is joined with the wings and landing gear, then moves down the assembly line for the engines, avionics and interiors. After rolling out the aircraft tests the systems and engines before its maiden flight to Boeing Field. There its is painted and fine tuned and delived to the customer.

The first of six -100 prototypes rolled out in December 1966, and made its maiden flight on 9 April 1967 piloted by Brien Wygle and Lew Wallick. During nearly 1,300 hours of flight testing it was discovered that the aircraft produced excess drag at high speeds, which could buckle the rear wing spar at loads only 34% above normal. The aircraft were modified with reinforcements, but at a cost to the weight and short-field performance. On 15 December 1967 the Federal Aviation Administration certified the -100 for commercial flight. The 737 was the first aircraft to have, as part of its initial certification, approval for Category II approaches. Lufthansa received their first aircraft on 28 December 1967 and on 10 February 1968 became the first non-American airline to launch a new Boeing aircraft. Lufthansa was the only significant customer to purchase the 737-100 and only 30 aircraft were ever produced.

The 737-200 made its maiden flight on 8 August 1967. It was certified by the FAA on 21 December 1967, and the inaugural flight for United was on 28 August 1968 from Chicago to Grand Rapids, Michigan. The lengthened -200 was widely preferred over the -100 by airlines.

In 1968 an improvement to the thrust reversal system was introduced. The improvement became standard on all aircraft after March 1969, and a retrofit was provided for active aircraft. Boeing fixed the drag issue by introducing new longer nacelle/wing fairings, and improved the airflow over the flaps and slats. The production line also introduced an improvement to the flap system, allowing increased use during take-off and landing. All these changes gave the aircraft a boost to payload and range, and improved the short-field performance. In May 1971, after aircraft #135, all improvements, including more powerful engines and a greater fuel capacity, were incorporated into the 737-200, giving it a 15% increase in payload and range over the original -200s. This became known as the 737-200 Advanced, which became the production standard in June 1971.

In 1970, Boeing received only 37 orders. Facing financial difficulties, Boeing considered closing the 737 production line and selling the design to Japanese aviation companies. After the cancellation of the Boeing Supersonic Transport, and the scaling back of 747 production, enough funds were freed up to continue the project. In a bid to increase sales by offering a variety of options, Boeing offered a 737C (Convertible) model in both -100 and -200 lengths. This model featured a 340 x 221 cm (134 x 87 in) freight door just behind the cockpit, and a strengthened floor with rollers which allowed for palletized cargo. A 737QC (Quick Change) version with palletized seating allowed for faster configuration changes between cargo and passenger flights. With the improved short-field capabilities of the 737, Boeing offer the option of the -200 was the gravel kit, which enables this aircraft to operate on remote, unpaved runways. Until retiring its -200 fleet in 2007, Alaska Airlines utilized this option for some of its rural operations in Alaska. With the retirement of these aircraft, some airports, such as Red Dog Airport, have upgraded runway facilities from gravel to paved.

In 1988 the initial production run of the -200 model ended after producing 1,114 aircraft. The last one was delivered to Xiamen Airlines on 08 August 1988.

Newer variants
Development began in 1979 for the 737's first major facelift. Boeing wanted to increase capacity and range, incorporating improvements to upgrade the plane to modern specifications, while also retaining commonality with previous 737 variants. In 1980 preliminary aircraft specifications of the variant, dubbed 737-300, were released at the Farnborough Air Show.

The CFM56-3B-1 turbofan engine was chosen to power the aircraft, which yielded significant gains in fuel economy and a reduction in noise, but also posed an engineering challenge given the low ground clearance of the 737 and the larger diameter of the engine over the original Pratt and Whitney engines. Boeing and engine supplier CFMI solved the problem by placing the engine ahead of the wing, and by moving engine accessories to the sides of the engine pod, giving the engine a distinctive non-circular air intake.

The passenger capacity of the aircraft was increased to 149 by extending the fuselage around the wing by 2.87 m (9 ft 5 in). The wing incorporated a number of changes for improved aerodynamics. The wing tip was extended 9 in (23 cm), and the wing span by 1 ft 9 in (53 cm). The leading-edge slots and trailing-edge flaps were adjusted. The flight deck was improved with the optional EFIS (Electronic Flight Instrumentation System), and the passenger cabin incorporated improvements similar to those developed on the Boeing 757. The prototype -300, the 1,001st 737 built, first flew on 24 February 1984 with pilot Jim McRoberts. It and two production aircraft flew a nine month long certification program.

In June 1986 Boeing announced the development of the 737-400, which stretched the fuselage a further 10 ft (3.45 m), increasing the passenger load to 170. The -400s first flight was on 19 February 1988 and, after a seven-month/500-hour flight testing run, entered service with Piedmont Airlines that October.

The -500 series was offered, due to customer demand, as a modern and direct replacement of the 737-200. It incorporated the improvements of the 737 Classic series; allowing longer routes with fewer passengers to be more economical than with the 737-300. The fuselage length of the -500 is 1 ft 7 in (47 cm) longer than the 737-200, accommodating up to 132 passengers. Both glass and older style mechanical cockpits arrangements were available. Using the CFM56-3 engine also gave a 25% increase in fuel efficiency over the older -200s P&W engines.

The 737-500 was launched in 1987 by Southwest Airlines, with an order for 20 aircraft, and flew for the first time on 30 June 1989. A single prototype flew 375 hours for the certification process, and on 28 February 1990 Southwest Airlines received the first delivery. The 737-500 has become a favorite of some Russian airlines, with Aeroflot-Nord, S7 Airlines, and Rossiya Airlines all buying second-hand models of the aircraft to replace aging Soviet-built aircraft.

After the introduction of the -600/700/800 series, the -300/400/500 series was called the 737 Classic series.

Next Generation
Prompted by the modern Airbus A320, in 1991 Boeing initiated development of an updated series of aircraft. After working with potential customers, the 737 Next Generation (NG) program was announced on 17 November 1993. The 737NG encompasses the -600, -700, -800 and -900, and is to date the most significant upgrade of the airframe. The performance of the 737NG is essentially that of a new airplane, but important commonality is retained from previous 737. The wing was modified, increasing its area by 25% and span by 16 ft (4.88 m), which increased the total fuel capacity by 30%. New quieter more fuel-efficient CFM56-7B engines were used. All three improvements combined increases the 737s range by 900 nm, now permitting transcontinental service. A flight test program was operated by 10 aircraft; 3 -600s, 4 -700s, and 3 -800s.

The first NG to roll out was a -700, on 8 December 1996. This aircraft, the 2,843rd 737 built, first flew on 9 February 1997 with pilots Mike Hewett and Ken Higgins. The prototype -800 rolled out on 30 June 1997 and first flew on 31 July 1997, again with Hewett and Jim McRoberts. The smallest of the new variants, the -600s is the same size as the -500, was the last in this series to launch, in December 1997. First flying 22 January 1998, it was given certification on 18 August 1998.

In 2004, Boeing offered a Short Field Performance package in response to the needs of Gol Transportes Aéreos, who frequently operate from restricted airports. The optional package is available for the 737NG models and standard equipment for the 737-900ER. The enhancements improve takeoff and landing performance.

Boeing has already hinted that a "clean sheet" replacement for the 737 (internally dubbed "Boeing Y1") could follow the Boeing 787.

On 13 February 2006, Boeing delivered the 5,000th 737 to Southwest Airlines. This 737-700 is the 447th 737 to join the carrier's all-Boeing 737 fleet.

On 21 August 2006, Sky News alleged that Boeing's Next Generation 737s built from 1994 to 2002 contained defective parts. The report stated that various parts of the airframe produced by Ducommun were found to be defective by Boeing employees but that Boeing refused to take action. Boeing said that the allegations were "without merit".

Design description
Engines on the 737 Classic series (300, 400, 500) and Next-Generation series (600, 700, 800, 900) appear not to have circular inlets, as most aircraft do. The accessory gearbox was moved from the 6 o'clock position under the engine to the 4 o'clock position (forward looking aft). This was done because the 737 sits lower to the ground than most airplanes and the original 737s were designed for small P&W engines, but additional ground clearance was needed for the larger CFM56 engines. This side-mounted gearbox gives the engine a somewhat triangular rounded shape. Boeing and CFM International, the engine manufacturer, claim that the shape actually yields slightly improved performance. The necessary nacelle redesign is known in the industry as "hamsterisation", because of the resemblance of the shape to the rodent. Because the engine is so close to the ground, 737-300s and later are more prone to engine foreign-object damage (FOD).

737s are not equipped with fuel dump systems. Depending upon the nature of the emergency, 737s either circle to burn off fuel or land overweight. Also, the 737 has no full doors covering the main landing gear. The main landing gear (under the wings at mid-cabin) rotate into wells in the plane's belly, the legs being covered by partial doors, and "brush-like" seals aerodynamically smooth (or "fair") the wheels in the wells. The sides of the tires are exposed to the air in flight. "Hub caps" complete the aerodynamic profile of the wheels. It is forbidden to operate without the caps, because they are links to the ground speed sensor that interfaces with the anti-skid brake system. When observing a 737 take off, or at low altitude, the dark circles of the tires can be plainly seen. Boeing states that this design saves weight and reduces complexity.

Most 737 cockpits are equipped with "eyebrow windows" positioned above the main glareshield. Eyebrow windows were a feature of the original 707. They allowed for greater visibility in turns, and offered better sky views if navigating by stars. With modern avionics, they became redundant, and many pilots actually placed newspapers or other objects in them to block out sun glare. They were eliminated from the 737 cockpit design in 2004, although they are still installed in military variants and at customer request. These windows are sometimes removed and plugged, usually during maintenance overhauls and can be distinguished by a metal plug which differs from smooth metal which appears in later aircraft that were not originally fitted with the windows.

Blended winglets are available as retrofits and in production on newer 737 aircraft. These winglets stand approximately 8 feet tall and are installed at the wing tips. They help with reduced fuel burn (by reducing vortex drag), reduced engine wear, and less noise on takeoff.

A short-field design package is available for the 737-600, -700 and -800, allowing operators to fly increased payload to and from airports with runways under 5,000 feet. The package consists of sealed leading-edge slats (improved lift), a two-position tail skid (enabling reduced approach speeds) and increased flight spoiler deflection on the ground. These improvements are standard on the 737-900ER.

Variants
The 737 models can be divided into three generations, including nine major variants. The "Original" models consist of the 737-100, 737-200/-200 Advanced. The "Classic" models consist of the 737-300, 737-400, and 737-500. The "Next Generation" variants consist of the 737-600, 737-700/-700ER, 737-800, and 737-900/-900ER. Of these nine variants, many feature additional versions.

737 Original

Boeing 737-100
The initial model was the 737-100. It was launched by Lufthansa in 1965 and entered service in 1968. The aircraft is the smallest variant of the 737. 30 737-100s were ordered and delivered. No 737-100s remain in service. The original Boeing prototype, last operated by NASA, retired more than 30 years after its maiden flight, and is on exhibit in the Museum of Flight in Seattle.

Boeing 737-200
The 737-200 is a 737-100 with an extended fuselage. It was launched by United Airlines in 1965 and entered service in 1968. The 737-200 Advanced is an improved version of the -200, introduced by All Nippon Airways on 20 May 1971.[49] The aircraft has improved aerodynamics, automatic wheel brakes, more powerful engines, more fuel capacity and longer range than the -200.[50] Boeing also provided the 737-200C (Convertible), that allowed conversion between passenger and cargo use and the 737-200QC (Quick Change), facilitating rapid conversion between roles. The last delivery of a -200 series aircraft was in August 1988.[51] A large number of 737-200s are still in service, mostly with "second tier" airlines and those of developing nations. They are being phased out because of poor fuel efficiency, high noise emissions (despite the vast majority having had their JT8Ds fitted with hush kits) and escalating maintenance costs. This plane was able to operate on gravel runways after a gravelkit was installed, this was done in Alaska.
Nineteen 737-200s were converted to be used to train aircraft navigators for the U.S. Air Force, designated T-43. Some were modified into CT-43s which are used to transport passengers. The first one was delivered on 31 July 1973 and the last on 19 July 1974. The Indonesian Air Force ordered three modified 737-200s, designated Boeing 737-2x9 Surveiller. They were used as Maritime reconnaissance (MPA)/transport aircraft, fitted with SLAMMAR (Side-looking Multi-mission Airborne Radar). The aircraft were delivered between May 1982 and October 1983.

737 Classic

The new series featured CFM56 turbofan engines, which yielded significant gains in fuel economy and a reduction in noise, but also posed an engineering challenge given the low ground clearance of the 737. Boeing and engine supplier CFMI solved the problem by placing the engine ahead of (rather than below) the wing, and by moving engine accessories to the sides (rather than the bottom) of the engine pod, giving the 737 a distinctive non-circular air intake. The wing incorporated a number of changes for improved aerodynamics.

Boeing 737-300
The 737-300 was launched in 1981 by USAir becoming the first model of the 737 Classic series. The aircraft has a typical capacity of 128 passengers in a two class configuation (137 seats in a one class coach seating configuration). The 300 series remained in production until 1999 when the last aircraft was delivered to Air New Zealand on December 17, 1999.

Various modifications have been made to aircraft previously in service. The 737-300 can be retrofitted with Aviation Partners Boeing winglets. The 737-300 retrofitted with winglets is designated the -300SP (special performance). Used passenger -300 aircraft have also been converted to freighter versions. The Lockheed Martin CATBird is a modified 737-300 with the nose of a Lockheed F-35 Lightning II, a pair of canards, and (inside) an F-35 cockpit; to be used to flight test the F-35's complete avionics suite.

Boeing 737-400
The 737-400 was stretched beyond the 737-300, primarily to accommodate charter airlines. Piedmont Airlines and Pace Airlines were the launch customers. The -400 was launched in 1985 and entered service in 1988 with Piedmont.

The 737-400F was not a model delivered by Boeing but a converted 737-400 to an all cargo aircraft. Alaska Airlines was the first to convert one of their 400s from regular service to an aircraft with the ability to handle 10 pallets. The airline has also converted two more into fixed combi aircraft for half passenger and freight. These 737-400 Combi aircraft are now in service.

Boeing 737-500
The 737-500 was launched in 1987 by Southwest Airlines and entered service in 1990. The fuselage length of the 737-500 is similar to the 737-200 while incorporating the improvements of the 737 Classic series. It offered a modern and direct replacement of the 737-200, while also allowing longer routes with fewer passengers to be more economical than with the 737-300. The last -500 was delivered to All Nippon Airlines on 26 July 1999.

The 737-500 has become a favorite of some Russian airlines, with Aeroflot-Nord, S7 Airlines, and Rossiya Airlines all buying second-hand models of the aircraft to replace aging Soviet-built aircraft.

737 Next Generation

In November 1993, Boeing's board of directors authorised the Next Generation program to replace the 737 Classic series. The -600, -700, and -800 series were planned. By the early 1990s, it became clear that the new Airbus A320 was a serious threat to Boeing's market share, as Airbus won previously loyal 737 customers such as Lufthansa. After engineering trade studies and discussions with major 737 customers, Boeing proceeded to launch the 737 Next Generation series.

New features included:
- Improved CFM56-7 turbofan engine, 7% more fuel efficient than the CFM56-3
- Intercontinental range of over 3,000 nautical miles (5,556 km).[58]
- Increased fuel capacity and higher MTOW
- Six-screen LCD glass cockpit with modern avionics, retaining crew commonality with previous generation 737
- Passenger cabin improvements similar to those on the Boeing 777, featuring more curved surfaces and larger overhead bins than previous generation 737s. The Next Generation 737 interior was also adopted on the Boeing 757-300.
- New airfoil section, increased wing span, area, and chord
- Redesigned vertical stabilizer

Boeing 737-600
The 737-600 is the direct replacement of the 737-500 and competes with the A318. This is the only Boeing 737 still in production that does not include winglets as an option. The 737-600 was launched by Scandinavian Airlines System in 1995 with the first aircraft delivered on 18 September 1998. 69 aircraft have been delivered with no further announced unfilled orders as of December 2007. The most recent delivery was on 14 September 2006 to WestJet.

Boeing 737-700
The 737-700 was the first of Next Generation series when it was launch customer Southwest Airlines ordered the variant in November 1993. The variant entered service in 1998. It replaced the 737-300 in Boeing's lineup, and its direct competitor is the A319. It typically seats 132 passengers in a two class cabin or 149 in all economy configuration.

The 737-700C is a convertible version where the seats can be removed from the plane to carry cargo. There is a large door on the left side of the aircraft. The US Navy was the launch customer for the 737-700C.

Boeing launched the 737-700ER on January 31, 2006. All Nippon Airways is the launch customer, with the first one delivered on 16 February 2007. The 737-700ER is a mainline passenger version of the BBJ1 and 737-700IGW. It combines the 737-700 fuselage with the wings and landing gear of a 737-800. It will offer a range of 5,510 nautical miles (10,205 kilometers), with seating for 126 passengers in a 2-class configuration. A competitor to this model would be the A319LR. The 700ER has the second longest range for a 737 after the BBJ2. It is able to fly transatlantic services such as FlyGlobespan services from Glasgow to Boston and Toronto.

All Nippon Airways, Japan’s second-biggest carrier, is to pioneer the model in Asia with a daily service between Tokyo and Mumbai. ANA’s service, believed to be the first all-business class route connecting to a developing country, was to start in September 2007 and use a Boeing 737-700ER outfitted with 36 seats and an extra fuel tank.

The C-40A Clipper is a 737-700C used by the U.S. Navy as a replacement for the C-9B Skytrain II. The C-40B and C-40C are used by the US Air Force for transport of Generals and other senior leaders. The Boeing 737 AEW&C is a 737-700IGW roughly similar to the 737-700ER. This is an Airborne Early Warning and Control (AEW&C) version of the 737NG. Australia is the first customer (as Project Wedgetail), followed by Turkey and South Korea, with Italy anticipated.

Boeing 737-800
The 737-800 is a stretched version of the 737-700, and replaces the 737-400. It also filled the gap left by Boeing's discontinuation of the McDonnell Douglas MD-80 and MD-90 after Boeing's merger with McDonnell Douglas. The -800 was launched by Hapag-Lloyd Flug (now TUIfly) in 1994 and entered service in 1998. The 737-800 seats 162 passengers in a two class layout, or 189 in one class, and competes with the A320.

An executive conversion is offered as the BBJ2. For many airlines in the U.S., the 737-800 replaced aging Boeing 727-200 trijets.

The P-8 Poseidon is a 737-800ERX ("Extended Range") that, on 14 June 2004, Boeing's Integrated Defense Systems division beat Lockheed Martin in the contest to replace the P-3 Orion maritime patrol aircraft. Eventual orders may exceed 100 from the US Navy. The P-8 is unique in that it has 767-400ER-style raked wingtips, instead of the blended winglets available on other 737NG variants.

Boeing 737-900
Boeing later introduced the 737-900, the longest variant to date. Because the -900 retains the same exit configuration of the -800, seating capacity is limited to 177 seats in two classes, or 189 in a single-class layout. The 737-900 also retains the MTOW and fuel capacity of the -800, trading range for payload. These shortcomings until recently prevented the 737-900 from effectively competing with the Airbus A321.

Alaska Airlines launched the 737-900 in 1997 and accepted delivery on 15 May 2001. There are no announced orders that have not been delivered yet. 52 aircraft have been delivered. The most recent delivery was on 11 August 2005 to Shenzhen Airlines.

The 737-900ER, which was called the 737-900X prior to launch, is the newest addition and the largest variant of the Boeing 737 line and was introduced to meet the range and passenger capacity of the discontinued 757-200 and to directly compete with the Airbus A321.

An additional pair of exit doors and a flat rear pressure bulkhead increase seating capacity to 180 passengers in a 2-class configuration or 215 passengers in a single-class layout. Additional fuel capacity and standard winglets improve range to that of other 737NG variants.

The first 737-900ER was rolled out of the Renton, Washington factory on August 8, 2006 for its launch customer, Lion Air. On April 27, 2007, Boeing delivered the first 737-900ER to Lion Air. The airplane features a special dual paint scheme that combines the Lion Air lion on the vertical stabilizer and the Boeing livery colors on the fuselage. Lion Air has ordered 122 737-900ERs to be delivered by 2013.

Boeing Business Jet
After the introduction of the next generation series (-600 to -900ER), Boeing introduced the Boeing Business Jet (BBJ) series. The BBJ1 was similar in dimensions to the 737-700 but had additional features, including stronger wings and landing gear from the 737-800, and has increased range (through the use of extra fuel tanks) over the other 737 models.

Plans for a business jet version are not new. In the late 1980s, Boeing marketed the Boeing 77-33 jet, a business jet version of the 737-300.[63] The name was short-lived.

Operators
The 737 is operated by more than 500 airlines, flying to 1,200 destinations in 190 countries. With over 7000 aircraft ordered, over 5000 delivered, and over 4500 still in service, at any given time there are over 1,250 airborne worldwide. On average, somewhere in the world, a 737 takes off or lands every five seconds. Since entering service in 1968, the 737 has carried over 12 billion passengers over 120 billion km (65 billion nm), has accumulated more than 296 million hours in the air. The 737 represents more than 25% of the worldwide fleet of large commercial jet airliners.

Incidents

Accidents summary
Statistics as of January 1, 2007:
- Hull-loss Accidents: 115 with a total of 3,272 fatalities
- Other occurrences: 6 with a total of 242 fatalities
- Hijackings: 96 with a total of 325 fatalities

Recent notable accidents
- 14 August 2005 - Helios Airways, Flight 522, a 737-300 with 121 on board suffered a loss of cabin pressure. It is suspected that the pressure regulating valve was left open in the manual position, and caused depressurization during the ascent. All 121 aboard the aircraft were killed.

- 29 September 2006 - Gol Transportes Aéreos, Flight 1907, a 737-800 Brazilian airliner with 154 people on board crashed following a midair collision with a Embraer Legacy 600. All on board the 737 were killed. The Legacy landed safely at a Brazilian Air Force Base.

- 29 October 2006 - ADC Airlines, Flight 53, a 737-200 crashed during a storm shortly after takeoff from Abuja, Nigeria. All but seven of the 104 passengers and crew are reported to have been killed.

- 1 January 2007 - Adam Air, Flight 574, a 737-400 carrying 102 people went missing near a mountainous area during stormy weather in Indonesia. The plane was on a two-hour flight from Juanda International Airport, Surabaya, East Java to Sam Ratulangi Airport, Manado, on Sulawesi's northern tip and carried six crew and 96 passengers, including 11 children.

- 7 February 2007 - a Brazilian judge banned 737-700 and -800 aircraft from operating out of São Paulo’s Congonhas airport due to recent runway overrun incidents during wet weather.

- 7 March 2007 - Garuda Indonesia Flight 200, a 737-400 carrying 140 people burst into flames while landing in Yogyakarta, Indonesia. A total of 22 people were killed.

- 5 May 2007 - Kenya Airways Flight 507, a 737-800 carrying 106 passengers and nine crew lost contact and crashed on a flight to Nairobi, Kenya from Abidjan, Côte d'Ivoire, after making a scheduled stop at Douala, Cameroon.

- 20 August 2007 - China Airlines Flight 120, a Boeing 737-800 inbound from Taipei, caught fire shortly after landing at Naha Airport in Okinawa Prefecture, Japan. There were no fatalities. Following this incident, the FAA issued an Emergency Airworthiness Directive (EAD) on 25 August ordering inspection of all Boeing 737NG series aircraft for loose components in the wing leading edge slats within 24 days. On 28 August, after initial reports from these inspections, the FAA issued a further EAD requiring a detailed or boroscope inspection within ten days, and an explicit tightening of a nut-and-bolt assembly within 24 days.