Boeing 737 Classic
The Boeing 737 Classic is the second major generation of the Boeing 737, comprising the 737-300, 737-400 and 737-500. Boeing combined the original 737 fuselage cross-section with CFM International CFM56-3 high-bypass turbofan engines, revised aerodynamics, increased span and updated flight-deck systems. It delivered 1,988 Classics between 1984 and 2000.[1][2]
Development
Boeing developed the 737-300 to increase the original 737's capacity, range and fuel efficiency while preserving the family's basic fuselage and low ground stance. The programme adopted the CFM56-3, whose high bypass ratio offered a substantial change from the Pratt & Whitney JT8D engines on the 737-100 and -200.[3][4]
The first 737-300 rolled out at Renton on 17 January 1984 and flew on 24 February. USAir and Southwest Airlines were the launch customers. The -300 established the revised wing, tail, flight deck and powerplant installation used by the Classic family.[1]
Boeing next developed the stretched 737-400 for higher-capacity routes. It rolled out on 26 January 1988, with Piedmont Airlines as launch customer, and first flew on 19 February. The shorter 737-500 followed for markets needing lower capacity with the Classic generation's engines and systems; Southwest was its launch customer, and the first flight took place on 30 June 1989.[1][5]
The “Classic” label distinguishes these models from the earlier 737-100/-200 and the later 737 Next Generation. The FAA's Flight Standardization Board report explicitly groups the 737-300, -400 and -500 under the Classic marketing name while retaining the common B-737 pilot type rating.[2]
Design
The Classic retains the 737's narrowbody, six-abreast cabin, low-mounted swept wing, conventional tail and inward-retracting main landing gear. Its low ground clearance simplified passenger and baggage handling at airports with limited equipment, but constrained installation of the larger-diameter CFM56.[4]
CFM56 installation
Boeing and CFM International mounted the CFM56-3 forward of the wing and reshaped its accessory arrangement and nacelle to obtain ground clearance. The resulting inlet has a flattened lower profile rather than a circular cross-section. The engines are quieter and more fuel-efficient than the JT8Ds they replaced, while requiring Classic-specific pylons, systems and maintenance data.
All three variants use the CFM56-3 family, but multiple engine marks and thrust ratings were certificated. An individual aircraft record should identify the installed engine model from technical records instead of treating “CFM56-3” as a complete engine specification.[4][2]
Wing, controls and flight deck
Compared with the early 737, the -300 introduced a larger-span wing and revised leading- and trailing-edge devices. The aircraft retained conventional hydraulically powered primary controls with mechanical reversion provisions rather than adopting fly-by-wire.
The flight deck introduced electronic flight-instrument displays while retaining sufficient commonality for the B-737 type rating. Equipment standards vary greatly across surviving aircraft because operators have fitted later navigation, surveillance, terrain-warning and cockpit-display modifications.[2]
Cabin and cargo holds
The cabin cross-section is shared with other 737 generations. Passenger layouts normally use six-abreast economy seating, with airline-specific galleys, lavatories and premium cabins. The lower holds are manually loaded rather than designed around standard widebody containers.[4]
Variants
737-300
The 737-300 is 33.40 metres (109 ft 7 in) long. Boeing added fuselage sections forward and aft of the wing compared with the 737-200 and increased the wing and stabiliser spans. Its airport-planning document shows a typical 128-seat two-class arrangement, 134 seats in a representative all-economy layout and an FAA exit limit of 149.[4]
The -300 was the most successful Classic variant: 1,113 were built. Some passenger aircraft later received blended winglets, avionics upgrades or passenger-to-freighter conversions. Those changes are modifications to particular airframes and do not create additional Boeing production deliveries.[1]
737-400
The 737-400 stretches the -300 by 3.05 metres (120 inches), giving a length of 36.45 metres. Its larger cabin supports up to 168 passengers in Boeing's all-economy planning configuration. Structural and ground-handling differences include changes associated with the longer fuselage and higher weights.[4]
Boeing delivered 486. A significant number have subsequently been converted to freighters, typically with a large main-deck cargo door, strengthened floor and cargo-handling system. Conversion approval, payload and door arrangement depend on the specific supplemental type certificate and should be recorded separately from the underlying 737-400 model.[1]
737-500
The 737-500 is the shortest Classic, measuring 31.01 metres (101 ft 9 in). It was intended to replace the capacity of the 737-200 while offering the newer generation's engines and systems. Boeing's planning data gives an all-economy maximum of 132 seats.[4]
Boeing delivered 389. Its shorter fuselage generally traded capacity for range and performance relative to the -300, but actual payload-range capability varies by weight and engine standard.[1]
Specifications
| Characteristic | 737-300 | 737-400 | 737-500 |
| ICAO designator | B733 | B734 | B735 |
| Length | 33.40 m | 36.45 m | 31.01 m |
| Wingspan | 28.88 m | 28.88 m | 28.88 m |
| Representative two-class seating | 128 | 146 | 110 |
| Maximum planning/exit-limit seating | 149 | 168 | 132 |
| Engine family | CFM56-3 | CFM56-3 | CFM56-3 |
| Delivered | 1,113 | 486 | 389 |
Dimensions and seating values come from Boeing airport-planning data. Maximum take-off weight, fuel capacity and range differ by model, engine rating, auxiliary tanks and certificated weight option; they should not be represented by a single family-wide figure.[4]
Production
Boeing rolled out the final Classic on 9 December 1999 and delivered the last aircraft in 2000. The production total comprises 1,113 737-300s, 486 737-400s and 389 737-500s, for 1,988 Classics. Boeing's roll-out announcement separately counted the earlier 737-100 and -200 aircraft and should not be read as a Classic total.[1]
Production overlapped the introduction of the 737 Next Generation. That successor used a new wing, larger tail surfaces, longer-range capability and CFM56-7 engines while retaining the 737 fuselage cross-section and B-737 pilot type rating.[6][2]
Operational use and conversions
Classic 737s served network, low-cost, charter, cargo, government and corporate operators. The -300's capacity made it the predominant model, the -400 addressed denser sectors, and the -500 served thinner routes. As passenger fleets aged, many aircraft were retired, stored, dismantled or transferred to smaller operators.[3]
Passenger-to-freighter conversions have extended the lives of many -300s and -400s. A converted aircraft remains tied to its original Boeing MSN and model, while the conversion design, approval holder, payload, door and current operator form additional dated records. An old passenger delivery entry does not establish an aircraft's present configuration or status.
Current fleet counts are volatile and depend on whether databases include parked, stored, government and inactive aircraft. Registration-level pages should use a recent civil-register, operator or reputable fleet-database source and state the access date.
Related pages
Sources
737 Flight Standardization Board report — Federal Aviation Administration
737-300/-400/-500 reference guide — Boeing
737-300/-400/-500 market overview — Boeing