The right panel on the status bar gives information on errors detected by GSP during initialisation and simulation of the engine model:

•Calc.Error

Indicates an error during calculations within the component models. Often these are divisions by zero or gas model iteration errors due to impossible or erroneous (component)model specifications.

•Jac.Inv.Error

Indicates GSP could not determine the inverse of the linearisation Jacobian of the model during Newton-Raphson iteration towards a steady state or quasi-steady state point.

•Iter.Error

Indicates GSP stopped trying to iterate towards a steady state or quasi-steady state solution due to insufficient progress. This is usually caused by excessive steps in model input. If for example the fuel flow is changed in one step from the design point value to the idle value, GSP may not be able to iterate due to the usually very non-linear gas turbine engine operating range. The solution then is to move to the idle point in a few steps or a gradual transient (or steady state series) calculation.