Boeing 737 MAX 9 vs. McDonnell Douglas MD-11

The Boeing 737 MAX 9, a variant in the 737 MAX series, is a narrow-body, twin-engine airliner designed for short to medium-haul flights. Launched in 2017, the MAX 9 aims to replace the 737-900 from the NG Family. The 737 MAX 9 offers a spacious cabin that can comfortably seat 178 passengers, making it an ideal choice for airlines operating on popular routes with higher demand. The aircraft combines modern aerodynamics and advanced engine technology to enhance its operational efficiency, balancing fuel economy with performance. Powered by CFM International LEAP-1B engines, the 737 MAX 9 has a higher MTOW and longer range than the 737-900. The aircraft is equipped with features that reduce its environmental impact, including lower emissions and noise levels. The aircraft also has brand new winglets that contribute to better aerodynamics.

In the commercial aviation market, the Boeing 737 MAX 9 competes with similar-sized aircraft like the Airbus A321neo. With an estimated cost of $112 million, it is priced competitively with the A321neo.  While both aircraft incorporate advanced engine technologies, the A321neo bests the MAX 9 in range by nearly 400 nautical miles - crucial for solid Transatlantic viability. Even in higher density configurations, the MAX 9 has less seats than the A321neo. And launching six years after the Airbus, Boeing was slightly late to the long-range, narrow-body market momentum.

The 737 MAX 9 has been selected by various airlines worldwide, valued for its ability to serve a wide range of domestic and international routes efficiently. The launch customer back in 2018 was Lion Air. Today, United Airlines, Aeromexico, and Alaska Airlines all have substantial fleets of MAX 9s. The MAX 9 builds on the success of the 737-900 and other member of the previous generation of 737s. With the average age just two years old, it will be a key player in the global airline industry over the next couple decades. Airlines will continue to order the MAX 9 for its ability to balance range, efficiency, capacity, and advanced technology.

The McDonnell Douglas MD-11 is a wide-body, tri-jet airliner, recognized for its extended range and enhanced capabilities in long-haul commercial aviation. As a successor to the iconic DC-10, the MD-11 incorporated advanced technology and design improvements, making it a significant model in the evolution of wide-body aircraft. The MD-11 took its maiden flight in 1990, and was produced until the turn of the 21st century. There are no MD-11s servicing passenger flights today, but some MD-11 are still being used for freight operations with FedEx, UPS, and Western Global Airlines.

With a length of 61.6 meters (202.1 feet), the MD-11 is notably longer than the DC-10, which provided increased passenger and cargo capacity. This extension in length was complemented by a wingspan of 52.0 meters (170.5 feet), which included winglets for improved aerodynamic efficiency. The MD-11's was equipped with GE CF6-80C2s or PW4000 turbofan engines, which delivered a total maximum thrust of 822.0 kN (123,000 lbf). With a substantial fuel capacity of 146,173 liters (38,615 US gallons), the MD-11 boasts a range of approximately 12,455 kilometers (6,725 nautical miles), enabling it to operate on intercontinental routes with ease.

The MD-11 comfortably accommodated 298 passengers, and could be designed to fit over 340 in a higher density configuration. The most common configurations for the twin aisle jet included 9 seats to a row (3-3-3 or 3-4-2).

In the competitive landscape of long-haul airliners, the McDonnell Douglas MD-11 was positioned as an alternative to models like the Boeing 747 and the Lockheed L-1011 TriStar. By 2004, most carriers that utilized the MD-11 for long-haul passenger routes had replaced it with the Airbus A330, A340, and Boeing 777. When Boeing acquired McDonnell Douglas in 1997, it ultimately created internal competition for the MD-11 with the 767 and 777. A lack of interest from the market also lead to Boeing cutting production for the commercial variant short, while the freight version was continued for slightly longer.

KLM, Swissair, and Delta Air Lines were among the airlines who utilized the aircraft's range and capacity to expand their international route offerings. The MD-11's operational role was characterized by its ability to efficiently serve long-haul routes, offering a blend of passenger comfort and operational economics. Some airlines like China Eastern Airlines and Korean Air had converted their MD-11 aircraft into freighters rather than selling or retiring them.

The MD-11's production and service history reflect its role as a pivotal model in the wide-body aircraft segment. Its design and technological advancements, including the use of winglets and a glass cockpit, marked important steps in the advancement of commercial aircraft design. Although its production was eventually surpassed by more modern aircraft, the MD-11 remains a notable aircraft in the history of aviation, particularly for its contributions to long-haul air travel.