I am a PhD student on flight dynamics and control. This week I was given an assignment to do some research on methods of aircraft performance calculation. After some search on the Internet, I found that traditional methods depended on tabulated data on the airplane flight manual (APM), and about a decade ago, both Boeing and Airbus started to do performance calculation using "first principle" method.
I read on an Advisory Circular document that provides a definiton of this method:
A calculation using basic parameters such as lift, drag, power or thrust, etc. with the equations of motion. (AC No: 25.1581-1, Change 1.)
And an Airbus document gives some explanation on this method:
The next step in the performance calculation process, referred to as OCTOPUS (Operational and Certified Takeoff and landing Universal Software), not only offers the same advantages as TLC but also drastically changes the performance calculation method. It is no longer based on pre-computed data, but uses the “first principle” mode that allows a real on-time computation to benefit from a higher takeoff weight. Instead of smoothed pre-computed performance results, the OCTOPUS performance database contains all the airplane and engine characteristics, enabling performance computation based on physics equations. In addition, OCTOPUS introduces a new and improved takeoff chart format, with its use of multi-configurations and influences. ("Getting to Grips with Aircraft Performance", Airbus)
However, I have not found any paper or report on this topic. Is there anybody out there who could help by offering some details of this method, or, providing some references?