The following video shows how fuel (and many other things) are usually delivered to ground recovery teams in Afghanistan in support of Operation Enduring Freedom.
Notice what happens at 0:42 s: it looks like something is falling faster than the rest of the supply; a couple of pallets stacked with fuel barrels with a failed parachute.
Since those pallets that slam into the ground are either lost or damaged, with current fuel prices, that’s a not only a tactical concern (as ground troops don’t get the expected amout of supplies) as well as a significant waste of money.