The C-5A transport's four engines let out a collective groan as the gigantic plane lifted off the runway and climbed into the evening sky, hugging the S.C. coastline.
Inside the plane's cavernous cargo - strapped to its steel deck - were two vehicle simulators, designed to teach U.S. troops how to survive rollover crashes, and pallets of food and water.
In less than 24 hours, the cargo would reach Afghanistan for distribution to remote U.S. bases on the country's desert floor and rocky cliffs.
For eight years, Charleston has been a starting point for the 7,500-mile-long air bridge to the Afghan war.
Never miss a local story.
Eleven times a day, on average, Air Force C-5 and C-17 military transport aircraft take off from Charleston for Afghanistan.
Though invisible to the eye, the air bridge from Charleston demonstrates the key role the Lowcountry base is playing as the U.S. military ramps up the fight in Afghanistan.
"We're South Carolina's lifeline to Afghanistan," said Staff Sgt. Jeff Harmon of Boiling Springs, a specialist in loading the giant Charleston-based C-17 Globemasters.
C-5s, which make up amount 8 percent of the military transport plane departures from Charleston, fly into the Lowcountry from other Air Force bases in the United States.
The shift in military activity to Afghanistan - where President Obama has ordered 17,000 more U.S. troops be sent - is noticeable, said Lt. Col. Richard Williamson, on his second deployment in two years to the Persian Gulf region.
"As combat operations have switched from Iraq to Afghanistan, we have also shifted our warfighter mobility support to Afghanistan," said Williamson, commander of the 17th Airlift Squadron, based at Charleston.
When his C-17 squadron was deployed to the Persian Gulf region a year ago, "We flew almost exclusively to Iraq," Williamson said. This time around, most of the missions have been flown to Afghanistan, Williamson said.
That shift could become even more noticeable in the weeks and months to come. As U.S. casualties have dropped in Iraq, where a civilian government now is entrenched, they have soared in Afghanistan.
That country's future now is more fragile than ever - imperiled by a resurgent Taliban, government corruption and claims the August election was stolen by Afghan president Hamid Karzai. To restore stability, the U.S. commander in Afghanistan, Gen. Stanley McChrystal, wants up to 80,000 more troops, a request the Obama Administration is debating.
If those troops are sent, many will fly on planes from Charleston, as will their equipment and even food.
HELP FOR CIVILIANS
It is because the Air Force has planes like Charleston's C-17s, which can carry the equivalent of the contents of four 18-wheel trucks, that the U.S. government can fight wars in two countries, observers say.
"The Air Force's ability to quickly and efficiently deploy and redeploy its combat power makes it especially valuable," executive editor Adam Hebert wrote in the October issue of Air Force magazine. "Whereas ... ground forces are still relatively slow and ponderous, airpower can shift from one combat zone to another in a matter of hours."
Charleston's transport planes also play a role in winning the hearts and minds of Afghans, a key role in winning a counterinsurgency, commanders add.
The C-17s carry clothes, shoes and blankets destined for Afghanistan's civilians, as well as supplies for hospitals and clinics.
Airlift "is the game-changer" in Afghanistan, said Brig. Gen. Steve Kwast, commander of U.S. air forces in Afghanistan, based at Bagram Airfield.
"Every time you see a C-17 land at Bagram, you are seeing development, prosperity and security come to the Afghan people," Kwast said. "There is this sense of rejoicing."
Air Force Gen. Arthur Lichte, chief of the Air Force's transport command, said the ability of C-17s to haul humanitarian aid is "another instrument in the national security quiver just like the Berlin Airlift was."
"The first shot of the Cold War was the delivery of coal, flour and wheat, and a couple bars of candy," the four-star leader said. "And it all made a difference.
"The same is true today. We can have the same effect without firing a shot."
If it weren't for the hulking C-17s and C-5A Galaxies, the U.S. military would not be able to press the fight in land-locked, remote Afghanistan, observers say.
Everything from computers to modular buildings to fresh blood is moved into Afghanistan via C-17s and the C-5s. Airlifters also have returned home the remains of nearly 800 fallen U.S. service members who have died in Afghanistan.
Air travel, too, is the preferred way to get around Afghanistan, a country with about 33 million people, as big as Texas, dominated by mountain ranges with 25,000-foot, snow-capped peaks, and crisscrossed by goat paths.
Only one blacktop highway, called the "ring road," links the country's major cities, including the capital Kabul and its 4 million citizens.
Because of that geography, the threat of roadside bombs and bandits that ambush convoys, air transport is a safer, surer way to move people and gear down range.
"That's rough, rough terrain," said Lt. Gen. Mike Hostage, commander of Air Force Central Command, which oversees the U.S. air war in Afghanistan.
"Sometimes, air is the only way to get resupply to folks," said Hostage in a recent interview at his office at Sumter's Shaw Air Force Base.
There are doubts about how long troops can be resupplied by airlift. Afghanistan is a logistician's nightmare because up to 40 percent of nearly 200 U.S. bases in Afghanistan can be reached by air only.
"Dropping pallets is effective for small amounts, but it's not how you resupply somebody over the long term," Hostage conceded. While C-17s are used to make some airdrops, the military relies on smaller, more versatile, propeller-driven C-130 transport planes and CH-47 Chinook helicopters to deliver goods to the most remote outposts.
Charleston's role in supporting, first, the Afghan war and, later, the Iraqi invasion has grown.
Between the attacks on Sept. 11, 2001, and Sept. 15 of this year, more than 472,000 tons of cargo and about 50,000 passengers have departed from the Lowcountry base on C-17s and C-5s, according to the Air Mobility Command at Scott Air Force Base, Ill.
Since April 2007 alone, 3,800 life-saving mine-resistant, ambush-protected vehicles, or MRAPs, have been shipped from Charleston to U.S. troops in Afghanistan and Iraq.
Shipping via air is expensive.
Flying a C-17, ready to fly more than 90 percent of the time, costs $17,204 an hour, according to the Air Force.
The older, more mechanically temperamental C-5s cost about $33,857 an hour to fly, the report added. Even at that cost, only half the Air Force's C-5s can be coaxed into flying missions at any one time.
But on the battlefield, where lives are at stake, speed is crucial. So shipping a vehicle that can ward off the blast of a roadside bomb in a day or so via air transport trumps the four to six weeks it would take to ship it by sea at a fraction of the cost.
With more troops and gear expected to flow into Afghanistan, it's doubtful the workload will lighten anytime soon at Charleston or among its fleet of C-17s, Gen. Lichte said.
"It's hit a fever pitch," Lichte said. "I see a probably high operations tempo for C-17s and for Charleston until things settle down on this war on terror."
For the most part, the airmen don't mind.
"I get to do what I love, and that's to fly," said Capt. Derek Dupuis, a 26-year-old C-17 pilot from Greenville, who has flown several missions to Iraq and Afghanistan. "Your office is up in the clouds."
Staff Sgt. Harmon, 25, has been in the Air Force since he graduated from high school in 2002.
He's responsible for making sure his C-17 is loaded correctly, as well as executing airdrops over sometimes dangerous territory.
"We always have to keep in mind there are people who want to kill us," Harmon said.
But the rewards and sights can be awe-inspiring, he added.
"Sometimes, when we fly through the mountain valleys, all you see on both sides of you are walls of rock," Harmon said.
Nine hours after taking off from Charleston, Capt. Mark Enriques guides his C-5 through the low cloud ceiling. Ramstein Air Base in Germany, Enriques' midway point on his way to Afghanistan, is straight ahead.
As the plane's wheels touch down, a slight vibration is felt on the flight deck, some 30 feet above the runway surface.
"That was pretty sporty," Enriques says of the quick descent through the clouds before terming the flight "routine."
Just 28, Enriques already is a seasoned veteran of airlift missions.
It's easier for him to recall the number of continents that he has landed a C-5 on than the number of times he has made trips to Iraq or Afghanistan.
"I don't know, maybe 15 or 20 times," said Enriques of Hilo, Hawaii. "I'd have to think about it."
While his job requires him to spend about half the year away from home, Enriques judges the inconvenience worthwhile. He and his fellow crew members are doing their part in the war effort.
"Hopefully, this cargo helps the guys down range," Enriques said.