Have you ever considered making a Patrol Heli Guards plugin in the spirit of the Bradley Guards plugin?  That would be awesome!

Hello, have you found an answer to this request? I would also like this to be possible on my server.

same here. I would love a response to that

The solution exists, the Botrespawn plugin manages this, but it costs $40. 
Which I find relatively expensive. That's a shame.
At $20 I would have taken it without thinking, to support the creator's work.

Namtamrof

The solution exists, the Botrespawn plugin manages this, but it costs $40. 
Which I find relatively expensive. That's a shame.
At $20 I would have taken it without thinking, to support the creator's work.

It costs $40 because it is worth $40 ,it is updated on a regular basis and response from the dev is very fast,
you are not forced to buy it and there are more expensive plugins that do far less but i dont hear anyone crying about it.
If you want a free npc plugin use PlaguedNPC's or HumanNPC ,

in life you get what you pay for.