Recently, I installed Rustcord and observed that the Patrol Helicopter notifications weren't coinciding with the arrival of the Patrol Helicopter, they were occurring when the Chinook/CH47 arrived. Taking a look at the plugin (Rustcord.cs), at around line 3330, I see the conditional for this detection:
if (Entity is BaseHelicopter)
...then it eventually produces a RUST_OnHeliSpawn event message. The problem appears to be that BaseHelicopter is a base component for both the CH47 and the Patrol Helicopter, which is why it results in true if either helicopter arrives. Changing the conditional to "if (Entity is PatrolHelicopter)" fixed the issue, and I just wanted to mention this in case others were experiencing the same issue.