Boeing 737-400 vs. Boeing 737-500

The Boeing 737-400, part of the 737 Classic series, is a narrow-body, twin-engine airliner developed to meet the evolving requirements of the short to medium-haul market. First introduced in 1988, the 737-400 expanded upon the success of its predecessor, the 737-300. The -400 variant entered manufacturing shortly after finalization of design plans between Boeing and launch customer Piedmont Airlines (later merged into US Airways). It gives increased capacity and range, offering an option in between Boeing's 737-300 and the 757-200.

The fuselage incorporated a key 8 foot expansion to enable typical accommodation for up to 170 passengers in a 2-class layout. Other changes included increased weights and structural reinforcements, enhanced avionics/flight controls, and higher thrust CFM powerplants required for the heavier max takeoff figures. Cost efficiencies were achieved keeping cockpit continuity with the ubiquitous 737 flight deck suite.

Spanning 119.6 feet (36.5 meters) in length with a wingspan of 94.5 feet (28.8 meters), the 737-400 was designed to accommodate the growing demand for larger single-aisle aircraft. The aircraft typically seats 144 passengers, providing more space and comfort compared to earlier models in the series. This increased capacity made the 737-400 an attractive option for airlines seeking to transport more passengers on popular routes, without the need for a larger, wide-body aircraft. Equipped with two CFM International CFM56-3C1 engines, the 737-400 delivers a total thrust of 44,000 lbf (196.0 kN). This engine configuration, combined with a fuel capacity of 5,310 US gallons (20,100 liters), allows the aircraft to achieve a range of 2,079 nautical miles (3,850 kilometers).

In the competitive commercial aviation market of its time, the Boeing 737-400 contended with models like the McDonnell Douglas MD-80 series. Its introduction marked another milestone for Boeing in the evolution of the 737 family, solidifying the company's position in the market for short to medium-haul airliners. Airlines such as Alaska Airlines, Turkish Airlines, and British Airways incorporated the Boeing 737-400 into their fleets. The aircraft's operational role was significant, enabling these carriers to expand their route networks and increase flight frequencies, particularly in domestic and regional markets.

The Boeing 737-500, introduced in 1987 as part of the 737 Classic series, is a narrow-body, twin-engine airliner designed for short to medium-haul routes. Recognized for its compact size and efficiency, the 737-500 catered to airlines needing a smaller capacity jet with the performance qualities of the larger 737 models.

At 101.7 feet (31.0 meters) in length and with a wingspan of 94.5 feet (28.8 meters), the 737-500 was adept at serving routes that required flexibility for airport size and range. This aircraft was particularly appealing to airlines for its ability to operate efficiently on shorter and less dense routes, providing a practical solution for smaller markets. While the -400 expanded on the -300, the -500 was actually constructed to considerably smaller than the -300. Comparatively, the 737-500 is closest in size and capacity to the 737-200. Powered by two CFM International CFM56-3C1 engines, the Boeing 737-500 has a total thrust capability of 40,000 lbf (178.0 kN). With a fuel capacity of 5,310 US gallons (20,100 liters), it boasts a range of 2,376 nautical miles (4,400 kilometers). The 737-500's cruise speed of 495 mph (796 km/h) contributed to its reputation as a reliable and efficient aircraft for regional travel.

In the commercial aviation landscape of its time, the Boeing 737-500 was a competitor to aircraft like the McDonnell Douglas MD-80 series. Its introduction provided airlines with a versatile option in the 737 family, bridging the gap between the larger 737 models and the need for a more economical, smaller jet. Southwest Airlines was the first customer of the -500, making their first flight in 1989. Lufthansa, United Airlines, and Continental also operated the Boeing 737-500. The aircraft played a significant role in these fleets, enabling the expansion of domestic and regional networks.

The Boeing 737-500 has faced accelerated retirement due to its smaller size. A majority of models were out of service after just 21 years in service. Most freight companies didn't even have interest in turning the -500 into a cargo jet. The 737-500 was replaced by the 737-600 of the Next Generation series.