Hii Bentolila Yedida,
I understand you are unable to change the gain parameter for a subsystem inside 'Airframe'.
The 'set_param' function allows you to modify parameters of Simulink blocks, including subsystems.To change a parameter value inside a subsystem that is nested within another subsystem, you need to specify the full path to the parameter you wish to modify.
Here's an example that describes the condition:-
set_param('Model/Airframe/SubsystemName','Gain','Value ');
For better understanding of the 'set_param', kindly refer to following link:-https://in.mathworks.com/help/simulink/slref/set_param.html
