Draft:Boeing 747-500

The Boeing 747-500 was a proposed variant of the iconic Boeing 747, designed in 1986 as a propfan version of the Boeing 747.

Development
In January 1986, Boeing had outlined preliminary studies for a larger, ultra-long-haul version of the iconic Boeing 747, which they named the new design, the "747-500". The primary goal was to create an aircraft capable of flying ultra-long distances, such as the route between London, England and Sydney, New South Wales.

Design
The aircraft derivative would use engines evolved from unducted fan (UDF) (propfan) technology by General Electric, but the engines would have shrouds, sport a bypass ratio of 15–20, and have a propfan diameter of 10–12 feet.

The aircraft would be stretched (including the upper deck section) to a capacity of 500 seats, have a new wing to reduce drag, cruise at a faster speed to reduce flight times, and have a range of at least 8700 nmi, which would allow airlines to fly nonstop between London, England and Sydney, Australia.

The 747-500 was designed have been stretched to accommodate more passengers and additional fuel.

Cancelation
The reasons to why it was never manufactured was because of many reasons such as Changing market dynamics, as by the late 1980s, supersonic transports (like the Concorde) were no longer seen as direct competitors to subsonic airliners. Evolving engine technology, as the propfan engine faced challenges in terms of development and certification. There were also Economic considerations, as Boeing had to weigh the costs of redesigning and retooling against potential benefits.