Courage
He was brave enough to face Megatron, multiple times, to fight Decepticons, to spend his days arguing with the most corrupt politicians in the business, to tell Hide off, to face Ratchet in his worst moods, but there was no way in hell Sam was going to jump out of the airplane, protocol be damned.
"You'll be fine, Sam," Will assured, "You've got a first-rate parachute and the Autobots are all below us to make sure nothing goes wrong, which it won't."
"I can't do this, Will, I hate heights!" Sam protested.
"Sorry, kid, but those suits in D.C. are insistent on you training in full, especially after you got captured," Epps reminded him, "And that includes learning to do this."
"Damn," Sam muttered, slowly inching his way down the lowered ramp.
Taking a very deep breath, he jumped, and was suddenly in freefall.
Pretty sure he was having a heart attack, Sam yanked on the cord hard, sighing in relief as the chute caught the air resistance and his descent slowed drastically.
He landed next to Bumblebee, who began playing an assortment of different people cheering.
"I am never, ever, doing that again."