BAGHDAD — Lifting their arms in roller-coaster fashion, the soldiers whoop and then sing "Leaving on a Jet Plane" as their C-17 military plane takes off from Kuwait, bound for Baghdad, with a belly full of Indiana National Guard soldiers.

They sit on what look like used seats from a commercial airplane, frayed and packed in tight rows like eggs in a crate. The dull gray cargo plane has smooth edges and nothing shiny — a no-nonsense, strictly functional design. But it is boldly massive, with a 170-foot wingspan, dwarfing all other military aircraft on the airfield in Kuwait.

Staring at the dust-powdered floor, Spc. John Bickenstaff, 24, of Logansport, Ind., pulled at the collar of his body armor. His uniform for the flight last month was spotless, without sweat stains, and his boots had full tread. Summertime freckles covered his face and hands, even his forehead and sunburned neck, and he had a boyish pout. He seemed unaware of the excitement around him.

This was Bickenstaff's first tour in Iraq. And his second flight, ever.

"I told my kids I'm going to Iraq to play Army," he said then. They are 5 and 3.

Wedged between the seats and their gear, most soldiers fall asleep without tilting their heads. The plane has no windows. And the engine buzz is constant, loud and so numbing it is eventually unnoticeable.

Bickenstaff stays awake. He barely talks about Iraq. When he does, he shrugs, as if to say, "I just don't know."

An hour and a half later, wheels hit the ground and the soldiers wake, cargo jerking behind them. Dazed, they bang and lunge over the backpacks and rifles overflowing in the aisles, making their way out.

It's midnight. Baghdad greets them with a harsh, hot wind that stifles instead of relieves.

"Soon I'll be riding on top of a Humvee," Bickenstaff says.