Good job on this one! Helicopter movement is really well done. Loved that the guys were cheering during a flood :P
A couple suggestions:
Don't place the full float timer on screen, the constant movement of the numbers is annoying to see. To avoid this, you could cast it to an int. You can do this by writing (int) before the value you will show.
Not sure if this was a design decision, but supplies could be pushed by your heli and thrown to the water making them quite hard to pick up. You can constraint rigidbody rotations to avoid them from being toppled over.
Hope they are useful!