Boeing 737-400 vs. Boeing 737 MAX 7

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 MAX 7 is a narrow-body, twin-jet aircraft, and the smallest variant in the re-engineered 737 MAX family. The MAX 7 was originally announced in 2016, but has yet to fly for an airline as of 2023. It had its first flight on March 16, 2018, from the Boeing factory in Washington. The MAX 7 variant will reportedly get certification from the U.S. Federal Aviation Administration by April 2024, which will allow carriers to start flying the aircraft in late 2024. Southwest Airlines is expected to be the launch operator for the MAX 7. The 737 MAX 7 is designed to offer enhanced range and capacity for short to medium-haul flights, catering to airlines seeking a modern and flexible solution for their fleets. It is based on the original 737-700, and features very minor modifications in terms of size. It is expected to fly 1,000 nautical miles farther than the -700 with, 18% lower fuel costs per seat.

At 116.7 feet (35.6 meters) in length with a wingspan of 117.8 feet (35.9 meters), the 737 MAX 7 is adept at operating in diverse airport environments, including those with runway and size constraints. The aircraft typically seats 153 passengers, providing a blend of comfort and efficiency that is attractive for airlines operating regional routes. Powered by two CFM International LEAP-1B engines, the MAX 7 achieves a total thrust of 58,600 lbf (260.0 kN). It has a fuel capacity of 6,816 US gallons (25,800 liters), supporting a range of 3,850 nautical miles (7,130 kilometers). With a cruise speed of 521 mph (839 km/h), the 737 MAX 7 offers airlines an efficient means to cover short and medium distances.

Competitors for the MAX 7 include aircraft from Airbus like the A319neo and A220, and the E2 series from Embraer. Airlines such as Southwest Airlines and WestJet have selected the Boeing 737 MAX 7 for its operational flexibility and economic performance. The aircraft's capability to efficiently serve a range of regional routes makes it a valuable addition to airline fleets, especially for carriers looking to optimize their domestic and short-haul networks.