Create a mission with :
- a UH-80 named "heli"
- a SDV submarine named "submarine"
- description.ext with "enableDebugConsole = 1;"
Put this in a "watch line" in console : heli canSlingLoad submarine
It returns true.
Then execute this in the debug console :
heli enableRopeAttach false;
The "watch line" now returns false.
Take off with the helicopter and try to "Hook" the submarine. The action is ALLOWED.