How to complete the TP Industries Arm Race?

[Spotme]

Hi guys, I've been doing this mission for quite a while, however I've read that you only need to do 5 air drops & 5 Buggy pickups drops, yet I'm pretty sure I've done quite a few more than 5 each, and now stuck on an air drop that requires me to get out onto the runway, lift off and drop a bomb onto 1 moving train, and then fly across the map and bomb a boat(even though I've done something like this earlier, but wasn't timed) within 2mins 17 secs, which I'm finding impossible to complete due to the lack of time I have remaining to get to bomb the boat, even though I bomb the moving train immediately! Any help would be appreciated...