Plot hole: When the pilot rolls the plane to dump the suitcase carrying the bomb, Snake grabs hold and falls out of the plane with it. Snake saves himself from falling to his death by grabbing the railing of the open door. The weight of the suitcase would have either ripped one of Snake's limbs off or would have ripped the railing from the door.
Suggested correction: The suitcase was able to be picked up by Puggy so it didn't weigh enough to rip an arm off. Also railings on stairs have to be able to support lots of weight. They are designed to withstand 1000lbs+.