The more I think about this, the funnier it gets. How long would it take to unpack a drone, put a power source in it, and install a 1g shaped charge on a drone

The more I think about this, the funnier it gets. How long would it take to unpack a drone, put a power source in it, and install a 1g shaped charge on a drone and pack it away? 30 seconds? It seems like something you wouldn't exactly want to rush. So with 3 terrorists, assuming they worked 16 hour days, they'd have their devices ready in 4.75 years, assuming they didn't take any holidays.