Two massive C-17 cargo planes swooped low between cinder cones yesterday, hugging the hilly volcanic terrain of the military’s Pohakuloa Training Area on the Big Island as they dropped five tons of parcels from their gaping aft doors to a waiting Marine battalion below.

The scene — an airdrop resupply — has been played out in war zones in Iraq and Afghanistan, and recently in humanitarian relief efforts in Haiti. Yesterday, however, the pallets — holding thousands of pounds of scrap wood as fill-in for real supplies — were parachuted in a U.S. Air Force drill as part of the ongoing Rim of the Pacific exercises.

"Today’s mission was a great example of what the Air Force does every day as part of the larger joint mission," said Lt. Col. Maria Carl, director of public affairs for Pacific Air Forces. "With big exercises such as RIMPAC, it’s a good opportunity for us to practice that joint and combined interaction."

The two C-17 cargo planes left Hickam Air Force Base at about 6:30 a.m. yesterday and headed for the Big Island training area between Mauna Loa and Mauna Kea. The planes carried more than 10,000 pounds of supplies on pallets in their cargo holds to be parachuted out of the aircraft’s rear ramp. After descending to just 500 feet above ground level from a cruising altitude of 5,000 feet, the planes dropped their cargo one at a time over the Pohakuloa lava fields before heading toward Kona Airport for a quick touchdown. Meanwhile, the Kaneohe Bay-based 2nd Battalion, 3rd Division Marines waiting on the ground worked to recover the dropped parachutes and supplies.

On their way back to Honolulu, four F-16 fighters — also from Hickam — met up with the cargo jets, flying in formation and flanking the aircraft on both sides.

"It was great training for us," said Lt. Col. Andy Leshikar, commander of the Hickam-based 535th Airlift Squadron, which ran the drill. "It’s been very good for my pilots to do a little bit more over the land, where we do a lot of our training over the water here in Hawaii."

According to Leshikar, airdrops have become an important component of military efforts in Afghanistan, where troops operating in remote and treacherous areas depend on air-to-ground resupplies. The Pohakuloa Training Area’s moonlike terrain, he said, makes the mission similar to humanitarian aid runs that he led in Afghanistan’s mountainous regions in 2001.

"That really mimics Afghanistan well," Leshikar said.

Yesterday’s flight highlights the Air Force’s involvement in the international RIMPAC exercises happening in the water, on land and in the skies above the state this month. According to Lt. Col. Kenneth Hoffman, 15 Air Force units and 170 aircraft will take part in the joint military efforts by the time the military exercises end Aug. 1.

The Air Force has been involved in a number of recent RIMPAC events, including the sinking of the helicopter carrier New Orleans off Kauai on Thursday. An Air Force B-52 bomber dropped a 500-pound bomb on the decommissioned ship to support a firing squad of gunships from America, Japan, Australia and France.

The Air Force also dropped 25,000 pounds of supplies at the Pohakuloa site on June 24 as part of the exercise, marking the first time that a C-17 has been part of RIMPAC proceedings.

The Air Force’s involvement with foreign air forces will not, however, end with RIMPAC, Hoffman said.

"Here in the Pacific we do about 30 exercises a year, both jointly with our sister services and with our partner nations," Hoffman said. "We build relationships, we build trust, we build on a capability and we increase interoperability so that when real-world situations happen … we’re able to work together as a team."