Black Mesa: Uplink is the recreation of the Half-Life demo (HL: Uplink) released by Valve in early 1999 with featured content that was scrapped from the original storyline.
How do you trigger something beyond a trigger_changelevel, an entity that's in another BSP? Here is how it's done.
How to set up the Osprey to drop a squad of grunts in Black Mesa (Source).
How to set up a 50 cal. machinegun in Black Mesa (Source).
How to set up the TOW Missile system for Black Mesa (Source).