I found out how to fix it,it is a problem with ingame time being at the 0th month. Go download Enhanced native trainer, then ingame open up the trainer, go to Time and then skip days until the date is something like 01.01.2014.
Oups and forgot to add, @PieRGud, you might want to set the date to an valid day when you initialize the script to fix that bug.
@BeaTzZ
Great mod! I only had 1 mission which was of escorting the mayor to the airport, where is the second one? One suggestion is that after each mission, you should cleanup the vehicle,as If you kill the mayor where he spawns and then get another mission, the chopper will spawn at the same place as the old one and both will explode. Keep up the good work :)
Plugin does not work for me,each time I go into the dashcam view the plugin crashes on me.I am using v2.0 Here is a dump of my console whenever the plugin crash: http://pastebin.com/RuQBG530