Mi-8 Options Controls / Axis Commands : What does TDC Slew refer to?

[DieHard]

Mouse setup for TDC Slew - Horizontal and Vertical

 

What are these 2 axis commands used for?

[msalama]

Target Designation Control? Although that makes no sense with this chopper :huh:

[Art-J]

I suppose all aircraft have some trash code leftovers from the others in controls section. You can find TDC Slew command even in WWII planes assignments :D.