McDonnell Douglas DC-9-30 vs. McDonnell Douglas MD-11

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.

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.