The McDonnell Douglas Model 118E was a significant early design study that directly influenced one of the most successful short-haul airliners in aviation history. Developed in the early 1960s, the Model 118E represented an advanced turbofan-powered evolution of a short-range jet concept that ultimately became the legendary DC-9.
McDonnell Douglas Model 118E
Origins of the McDonnell Douglas Model 118E
In the late 1950s and early 1960s, Douglas Aircraft Company was studying replacements for piston-powered regional aircraft such as:
Douglas DC-3
Convair 240
Airlines were demanding:
Faster cruise speeds
Lower operating costs
Improved passenger comfort
Jet-powered reliability
The result was a series of design proposals under the “Model 118” designation. The Model 118E emerged as a refined variant featuring turbofan engines mounted at the rear fuselage — a configuration that would later define the DC-9 family.
Key Design Features of the Model 118E
1. Rear-Mounted Engines
One of the defining characteristics of the Model 118E was its twin rear-engine layout. This design offered:
Reduced cabin noise
Clean wing aerodynamics
Improved runway performance
Simplified wing structure
This configuration later became iconic on the McDonnell Douglas DC-9.
2. Turbofan Power
Unlike earlier turbojet designs, the Model 118E incorporated turbofan engines, which provided:
Better fuel efficiency
Lower noise levels
Improved takeoff performance
Reduced operating costs
This shift to turbofan propulsion was critical for short-haul economics.
3. Optimized for Short-Range Routes
The Model 118E was specifically tailored for:
High-frequency domestic routes
Secondary airports
Short-to-medium stage lengths
This market focus would later prove extremely successful with the DC-9 and its successors.
Transition to the DC-9 Program
In 1967, McDonnell Douglas was formed after the merger of McDonnell Aircraft and Douglas Aircraft Company. By that time, the 118E’s development path had already evolved into what became the DC-9 program.
The DC-9 first flew in 1965 and became one of the most successful short-haul jets ever built, spawning multiple derivatives:
McDonnell Douglas DC-9-30
McDonnell Douglas MD-80
McDonnell Douglas MD-90
Boeing 717
All of these aircraft trace their lineage back to early studies like the Model 118E.
Technical Specifications (Estimated Concept Parameters)
While detailed official specifications of the Model 118E are limited, historical analysis suggests it was designed to feature:
Seating capacity: ~65–90 passengers
Range: Approximately 1,000–1,500 nautical miles
Cruise speed: Around Mach 0.75–0.80
Twin rear-mounted turbofan engines
These parameters closely align with the early DC-9 variants.
Why the Model 118E Matters in Aviation History
1. Foundation of a Successful Aircraft Family
The Model 118E directly contributed to a family of aircraft that would serve airlines for decades.
2. Pioneering Rear-Engine Configuration
The clean-wing, T-tail, rear-engine layout became a standard configuration for many regional jets.
3. Economic Efficiency Focus
It reflected a shift in commercial aviation toward cost-per-seat-mile optimization — a philosophy that still defines aircraft design today.
Conclusion
The McDonnell Douglas Model 118E may not be widely known outside aviation history circles, but it played a crucial role in shaping one of the most successful short-haul jet families ever built.
By pioneering efficient turbofan use, rear-engine configuration, and short-haul optimization, the Model 118E laid the groundwork for the DC-9 legacy — a lineage that continues to influence modern narrow-body aircraft design.
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Frequently Asked Questions (FAQ) - McDonnell Douglas Model 118E
Was the McDonnell Douglas Model 118E ever built?
No. The Model 118E remained a design study, but it evolved into the DC-9 program.
What aircraft came from the Model 118E?
The DC-9 and its derivatives (MD-80, MD-90, Boeing 717) are its direct descendants.
Why was the rear-engine design chosen?
It reduced wing structural complexity, minimized cabin noise, and improved short-field performance.