Boeing 737-400 vs. McDonnell Douglas DC-9-30

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 McDonnel Douglas DC-9-30, a narrow-body jet airliner first introduced in 1966, stands as a significant aircraft in the evolution of commercial aviation. Designed during an era of rapid growth in air travel, the DC-9-30 was developed to meet the demands of short to medium-haul routes, offering airlines a more efficient and practical alternative to the larger jetliners of the time. The Series 30 of the DC-9 included four main sub-variants, -31, -32, -33, and -34. During its production, the -30 was by far the most popular model of the DC-9 with 585 units delivered.

This aircraft was initially developed as the Douglas DC-9, prior to August 1967 merger with McDonnell Aircraft. The DC-9-30 measures in at 36.4 meters (119.3 feet) in length. This size enabled it to operate efficiently in smaller airports and on shorter runways - a niche that was underserved at the time of its introduction. Powered by a pair of Pratt & Whitney PWJTD engines, the DC-9-30 has a total thrust output of 134.0 kN (30,000 lbf). Its fuel capacity of 13,900 liters (3,672 US gallons) gives the DC-9-30 a range of approximately 2,800 kilometers (1,512 nautical miles). This range was particularly advantageous for airlines looking to serve regional networks with an efficient and reliable jet.

The DC-9-30's typical five abreast seating layout can fit around 115 passengers, with a maximum of 127 in a high-density layout.

In its market segment, the McDonnel Douglas DC-9-30 was a key competitor to other short-haul aircraft of the era. Its introduction provided airlines with a jetliner that was not only smaller and more versatile than the larger, long-haul aircraft but also more efficient and economical for short to medium-range routes.

Airlines such as Delta Air Lines, Eastern Air Lines, and TWA were prominent operators of the DC-9-30, utilizing its capabilities to enhance their regional route networks. The aircraft's role in these fleets demonstrated its effectiveness in bridging the gap between propeller-driven airliners and larger jets, contributing significantly to the growth of regional air travel.

The McDonnel Douglas DC-9-30's production and service history highlight its importance as a practical and versatile aircraft in commercial aviation. The last DC-9 to ever be built was delivered in 1982. After its retirement, McDonnell Douglas went on to produce the MD-80 and the MD-95.