Boeing 737 Classic

The Boeing 737 Classic is the name given to the -300/-400/-500 series of the Boeing 737 following the introduction of the -600/-700/-800/-900 series. They are short- to medium- range, narrow-body jet airliners produced by Boeing Commercial Airplanes. The Classic series was introduced as the 'new generation' of the 737. Produced from 1984 to 2000, 1,988 aircraft were delivered.

Development and design
Following the success of the Boeing 737-200 Advanced, Boeing wanted to increase capacity and range, incorporating improvements to upgrade the plane to modern specifications, while also retaining commonality with previous 737 variants. Development began in 1979, and in 1980 preliminary aircraft specifications were released at the Farnborough Airshow. In March 1981, USAir and Southwest Airlines each ordered 10 aircraft, with an option for 20 more.



The new series featured CFM56 turbofan engines, yielding significant gains in fuel economy and a reduction in noise, but also posing 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. The wing tip was extended 9 inches (23 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 on the Boeing 757.

737-300


The prototype of the -300 rolled out of the Renton plant on January 17, 1984, and first flew on 24 February 1984. After it received its flight certification on November 14, 1984, USAir received the first aircraft on 28 November. A very popular aircraft, Boeing received 252 orders for it in 1985, and over 1000 throughout its production. The 300 series remained in production until 1999 when the last aircraft was delivered to Air New Zealand on 17 December 1999, registration ZK-NGJ.

In December 2008, Southwest Airlines selected Boeing to retrofit the 737-300 with a new set of instruments, hardware and software, in order to improve commonality with the 737-700, as well as to support the Required Navigation Performance initiative.

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 737-300 is now replaced by the 737-700 in the Boeing 737 Next Generation family.

737-400


The 737-400 design was launched in 1985 to fill the gap between the 737-300 and the 757-200, and competed with the Airbus A320 and McDonnell Douglas MD-80. It stretched the 737-300 another 10 ft (3.45 m) to carry up to 168 passengers. It included a tail bumper to prevent tailscrapes during take-off (an early issue with the 757), and a strengthened wing spar. The prototype rolled out on January 26, 1988, and flew for the first time on 19 February 1988.

The aircraft entered service on September 15, 1988, with launch customer Piedmont Airlines (25 aircraft ordered).

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 five more into fixed combi aircraft for half passenger and freight. These 737-400 Combi aircraft are now in service. The 737-400 is now replaced by the 737-800 in the Boeing 737 Next Generation family.

737-500
The -500 series was offered, due to customer demand, as a modern and direct replacement of the 737-200, incorporating the improvements of the 737 Classic series in a model that allowed 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 February 28, 1990 Southwest Airlines received the first delivery. The 737-500 has become a favorite of some Russian airlines, with Nordavia, Rossiya Airlines, S7 Airlines, Sky Express, Transaero, and Yamal Airlines all buying second-hand models of the aircraft to replace aging Soviet-built aircraft and/or expand their fleets. Aerolíneas Argentinas is replacing its 737-200s with second-hand 737-500s. The 737-500 is now replaced by the 737-600 in the Boeing 737 Next Generation family. However, unlike the 737-500, the 737-600 has been a slow seller for Boeing since its introduction, with only 69 aircraft delivered.

Civilian
As of July 2010, 1,651 Boeing 737 Classic aircraft were in commercial service. This includes 879 -300s, 419 -400s, and 353 -500s.

Military
Many countries operate the 737 passenger and cargo variants in government or military applications.
 * Brazil, Chile, Colombia, India (Indian Air Force), Indonesia, Kuwait, Mexico, Niger, Peru, Philippines (Philippine Air Force), South Korea, Republic of China on Taiwan (ROC's Air Force One), Thailand (Royal Thai Air Force), United Arab Emirates, Venezuela.
 * The People's Liberation Army Air Force (PLAAF) of the People's Republic of China operates a 737-300 (registered B-4052) as an airborne command post.

Deliveries

 * Source:

Accidents and incidents
The Boeing 737 Classic were involved in 26 Hull-loss Accidents with a total of 1,040 fatalities as of January 2010. Notable accidents and incidents involving the 737 Classics (-300/-400/-500) include:


 * January 8, 1989: Kegworth air disaster: British Midland Flight 92, using a 737-400, crashed outside of East Midlands Airport. Of the eight crew and 118 passengers, 47 passengers died.
 * February 1, 1991: USAir Flight 1493, using a 737-300, collided with a SkyWest Airlines Fairchild Metro III while landing in Los Angeles. All of the 12 people on the Fairchild Metro died while 20 passengers and 2 crew members out of 6 crew members and 83 passengers died on the 737.
 * July 26, 1993: Asiana Airlines Flight 733, using a 737-500, crashed into a mountain, killing 68 of 110 occupants.
 * September 8, 1994: USAir Flight 427, using a 737-300 with 127 passengers and 5 crew members, lost control after a rudder malfunction and crashed outside of Pittsburgh International Airport, killing everyone on board.
 * May 8, 1997: China Southern Airlines Flight 3456, using a 737-300, crashed while landing in Shenzhen, killing 33 of 65 passengers and 2 of 9 crew members.
 * December 19, 1997: SilkAir Flight 185, using a 737-300 with 97 passengers and 7 crew members, crashed into a river in Indonesia, killing everyone on board.
 * September 16, 1998: Continental Airlines Flight 475, using a 737-500, received windshear while landing in Guadalajara, Mexico. None of the passengers and crew received injuries. The aircraft was written off.
 * April 7, 1999: Turkish Airlines Flight 5904, using a 737-400 with six crew members, crashed in Turkey. All of the crew on board died; no passengers flew on that flight.
 * March 5, 2000: Southwest Airlines Flight 1455, using a 737-300, overran the runway upon landing in Burbank, California, United States and crashed. All of the passengers and crew survived.
 * March 3, 2001: Thai Airways International Flight 114, a 737-400 bound for Chiang Mai from Bangkok, was destroyed by an explosion of the center wing tank resulting from ignition of the flammable fuel/air mixture in the tank. The source of the ignition energy for the explosion could not be determined with certainty, but the most likely source was an explosion originating at the center wing tank pump as a result of running the pump in the presence of metal shavings and a fuel/air mixture. One flight attendant died.
 * May 7, 2002: EgyptAir Flight 843, using a 737-500, crashed during approach to Tunis, Tunisia. 3 of 6 crew members and 11 of 56 passengers died.
 * January 3, 2004: Flash Airlines Flight 604, using a 737-300 with 135 passengers and 13 crew members, crashed into the Red Sea, killing everyone on board.
 * June 9, 2005: 2005 Logan Airport runway incursion – A 737-300 operated by US Airways as US Airways Flight 1170 avoided collision with an Aer Lingus Airbus A330 at Logan Airport in Boston, Massachusetts, United States.
 * August 14, 2005: Helios Airways Flight 522, using a 737-300, suffered a gradual decompression which incapacitated 5 of the 6 crew members and all of the 115 passengers. The plane circled around Greece before crashing into a hill, killing everyone on board.
 * October 3, 2006: A man hijacked Turkish Airlines Flight 1476, Boeing 737-400. The aircraft landed in Italy and all of the passengers and crew survived.
 * January 1, 2007: Adam Air Flight 574, using a 737-400 with 96 passengers and six crew members, crashed off the coast of Sulawesi. the occupants were never found, and were presumed dead.
 * February 21, 2007: Adam Air Flight 172, using a 737-300, suffered a structural failure when landing at Juanda International Airport. All of the passengers and crew survived.
 * March 7, 2007: Garuda Indonesia Flight 200, using a 737-400, crashed upon landing at Adisucipto International Airport. Out of 133 passengers and 7 crew members, 20 passengers and 1 crew member died.
 * September 14, 2008: Aeroflot Flight 821, using an Aeroflot-Nord-operated 737-500, crashed shortly before its scheduled arrival at Perm, Russia. All 82 passengers and six crew members were killed.
 * December 20, 2008: Continental Airlines Flight 1404, a 737-500, veered off the runway and caught fire at Denver International Airport during an attempted departure. There were no casualties.
 * July 13, 2009: Southwest Airlines Flight 2294 while airborne had a football shaped hole appear and made an emergency landing at Charleston, WV. All 131 onboard survived. The cause is still under investigation.
 * January 16, 2010: UTair Aviation Boeing 737-500 VQ-BAC departed the runway on landing at Vnukovo International Airport and was substantially damaged when the nosewheel collapsed.
 * April 13, 2010: Merpati Nusantara Airlines Flight 836, operated by 737-300 PK-MDE overran the runway at Rendani Airport, Manokwari, Indonesia and broke up in two pieces. All 103 passengers and six crew escaped alive.
 * November 2, 2010: Lion Air Flight 712, operated by Boeing 737-400 PK-LIQ overran the runway on landing at Supadio Airport, Pontianak, coming to rest on its belly. All 174 passengers and crew evacuated by the emergency chutes, with few injuries reported.
 * April 1, 2011: Southwest Airlines Flight 812 had a six-foot tear in the upper fuselage on a flight from Phoenix Sky Harbor Airport to Sacramento International Airport, and diverted to Yuma after an emergency descent. One minor injury was reported.
 * January 23, 2012: A United Airlines Boeing 737-500 was preparing for a flight to Bush Intercontinental Airport in Houston from El Paso International Airport, when a maintenance-related engine run-up of the right-hand engine was carried out, sucking in and fatally injuring a mechanic.

Specifications
Sources: Boeing