j2 Freedom


The j2 Flight Plug-In is used to review flight test data and to identify the model corrections required.

One of the challenges related to flight test matching is that establishing a great match for one flight condition and using that to predict the next often leads to less than desirable results starting a manual and iterative solution loop. With j2 Flight, multiple test points can be analysed as a batch and the optimum solution for all cases found.

The detailed analytical approach provided by j2 Flight introduces a teachable, robust and repeatable process. This reduces the pressure and requirement on heavily experienced engineers who have learnt through experience which aspects of model corrections work. By having complete control of the model, we are able to perform a lot more activities mathematically.


j2 Classical will take the results of previous steady state analyses and linearise the aircraft about that point. At the same time it will calculate a state space set of matrices and all derivatives about the chosen point. From the state space system the eigenvalues and eigenvectors are established, and the subsequent modes of motion that these relate to. All this can be performed on the complete set of trim results in a matter of minutes. From these results we can then look at the stability characteristics.

From the full set of Eigenvalues for the complete flight envelope it is possible to establish any key areas of concern, then looking in more detail at the Eigenvalues, for Short Period say, at a given configuration. This means that trends can be found and evaluated.

With the pre-defined templates and charts, it is possible to evaluate characteristics against specific industry standards and requirements for the aircraft classification.

Even create user defined criteria and templates to look at things that are company specific.

All of this significant analytical work is completed in minutes and can be re-evaluated for every design change or refinement of the data model as more information becomes known about the aircraft.

Whether the user is working at Conceptual or Preliminary design stage or developing Certification procedures and test, the j2 Universal Tool-Kit with j2 Classical plug-in can be used throughout.


In using j2 Classical the analytical tasks that would normally take you man days and even man
weeks to complete are reduced to man hours and the added benefit of not having to move data
in and out of other software tools, with the resultant data transformation and error issues this
can produce, can yield further quality improvement and additional time savings.