Passenger Planes: Boeing 747

One of main enablers that made such a larger aircraft possible was the advent of high bypass turbofan engines. General Electric had applied the principal to the C5 Galaxy project. The high bypass turbofan delivered twice the power of turbojets which were in use at the time, and used one third less fuel. Pratt and Whitney were also working on this concept and in 1966 Pan AM, Boeing and Pratt and Whitney agreed to develop the JT9D as the powerhouse for the 747.