Douglas DC-9-40

The Douglas DC‑9‑40, the longest variant of the original DC‑9 family, entered service in 1973 as a product of McDonnell Douglas. Developed from the earlier DC‑9‑30, the -40 stretched the fuselage by 2.2 meters, allowing up to 124 passengers in a single‑aisle configuration and increasing payload capacity for short‑ to medium‑range routes. Powered by two rear‑mounted Pratt & Whitney JT8D‑9A turbofan engines, the aircraft offered improved fuel efficiency and quieter operation compared with its predecessors. The DC‑9‑40 retained the low‑wing, T‑tail layout that gave the series excellent short‑field performance, a trait that made it popular among regional carriers operating from airports with limited runway length. Over 200 units were built before production ended in 1981, and many were later converted to the MD‑88/MD‑90 lineage. The model’s reliability, simple maintenance, and ability to operate in diverse climates contributed to its longevity; several aircraft remained in commercial service for more than three decades. As a bridge between early jetliners and modern narrow‑body designs, the DC‑9‑40 cemented McDonnell Douglas’s reputation for versatile, cost‑effective airliners and influenced the development of later platforms such as the Boeing 717.

McDonnell Douglas

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