This paper discusses methods used in establishing, measuring, and controlling dispatch reliability of the 727 jet transport during its design.
Dispatch delays experienced by three commercial trunk airlines on 707-120B and 720B fleets through 82,187 departures in 11 months were categorized by ATA systems and individual components. Using individual comparison of each 727 system component or subassembly with its 707/720 counterpart as to the number of parts per component, duty cycle, design, operating environment, and accessibility delay factors were computed which expressed expected 727 delays as a given decimal fraction of 707/720 delays.
The overall 727 airplane delay factor was found to be 0.43 relative to the 707/720 delays, and the 727 dispatch reliability 98.02%.