A pallet is combat off-loaded from a C-17 Globemaster III June 20, 2009, at Tarin Kowt Airfield, Afghanistan. A recent test conducted by Air Mobility Command on semi prepared runway operations worldwide may help the C-17 be able to reach more forward operating locations such as Tarin Kowt. (U.S. Air Force photo/Staff Sgt. Shawn Weismiller)SCOTT AIR FORCE BASE, Ill. (AFNS) -- At many bases in Iraq and Afghanistan, Air Mobility Command airlifters, such as the C-17 Globemaster III, are landing on dirt runways bringing much-needed cargo to forward-deployed Soldiers, Marines, Airmen and coalition partners.
These "semi prepared" airfields are rugged and to improve operations to forward operating bases, AMC tested the capabilities of aircraft landing through semi prepared runway operations to increase the capability of the C-17 to meet warfighter needs.
This summer, AMC officials conducted SPRO testing at numerous undisclosed locations around the world using the C-17 platform. In their results, they found the C-17 is able to take off and land on 65 percent of the world's soils, whereas previously it was only able to take off and land on 6 percent.
The 59 percent increase in semi-prepared airfield take offs and landings for the C-17 means more stops can be made in areas otherwise not available. As recently as June, C-17s were the primary aircraft delivering more than 300 Army Stryker vehicles to military forces in bases throughout Afghanistan.
It's through "surge" operations such as the Stryker vehicle delivery where this increase in capability is significant, AMC officials said.
The Air Force's airlift support for the U.S. Central Command area of responsibility, which includes the C-17, was also recognized by Army Gen. David Petraeus, the CENTCOM commander, in August during the U.S. Air Forces Central change of command.
"Moving the mass formations of troopers and the iron mountain of materiel to perform our missions would be impossible without the phenomenal airlift support provided by the men and women of AFCENT," General Petraeus said.
Through the past three years, "crews flew more than 100,000 airlift sorties, moved more than 2 million personnel, delivered nearly 300,000 tons of cargo, and executed almost 2,000 airdrops throughout the CENTCOM AOR," he added.
Through SPRO testing, the dramatic capability increase of the C-17 was made possible by an additional piece of equipment, called a grip tester, that measures friction, said Maj. James Hill, the Chief of the Aircraft Test Management Branch at AMC headquarters at Scott Air Force Base, Ill. AMC, in an ongoing effort to continue to advance efficiencies while maintaining operational effectiveness, requested the test be performed to improve the C-17's overall mission.
"The C-17 SPRO test results will translate into expanded capability since rainy or wet weather conditions won't be such a limiting factor at austere locations with semi-prepared or dirt runways," Major Hill said.
The test results translate to customers being more likely to "get the goods" they need to complete their respective missions. Such deliveries might involve resupplying a forward operating base with ammunition, food, equipment parts or even everyday supplies such as toilet paper or light bulbs.
"Sometimes you have to get a little dirty to advance mobility capability," said Col. John Scorsone, the director of AMC Test and Evaluation. "This test effort will clear a path to future austere landing operations for the C-17."
The test evaluated how C-17s can fly into more restrictive locations and areas under varying weather conditions in an effort to best meet the needs of the warfighter as well as providing rapid response at home and abroad in response to humanitarian relief operations, Colonel Scorsone said.
Testing also evaluated C-17 takeoffs and landings in dry and various wet conditions, and increased the aircraft's operating weight capacity by 41,000 pounds.
"This payload increase allows more people and cargo to be transported at one time, possibly reducing the number of flights necessary to get supplies and troops to theater," Colonel Scorsone said. "Extra payload can also equate into more fuel the C-17 is able to carry, adding capability and flexibility to the aircraft."
The 140 flight-hour test involved flying multiple sorties to dirt strips around the country was an effort to characterize how different soil types hold up under multiple C-17 operations into and out of the particular ground environment.
The takeoffs and landings were evaluated by whether or not the aircraft had the distance and speed to takeoff or land as determined by a mission computer. The mission computer takes into account aircraft weight and environmental conditions. If the test dirt strip met the requirements as dictated by the mission computer, a test takeoff and landing were conducted.
To determine ground conditions, aircrews use a runway condition reading to determine the moisture levels of the ground, Major Hill said. The lower the number of an RCR, the higher the moisture content, the higher number of an RCR, the lower the moisture content. An RCR of 20 represents a relatively dry surface, while an RCR of four represents a surface as slick as ice.
Before this test, if any moisture was present on the dirt strip, ground personnel had to use an overly restrictive RCR rating of four which significantly limited the C-17's flexibility. If no moisture was present, an RCR rating of 20 was used, thereby increasing the C-17s velocity and capacity to deliver our mission to the warfighter as well as assist nations in need.
After this test, with the help of the grip tester, ground personnel will have a range of RCRs they can designate on a strip of land, making it a more usable runway.
"This testing allows us to determine a range of RCRs from four to 20, which will improve our overall ability to operate into otherwise overly restrictive locations," Major Hill said. "We will be able to get into more locations under varying weather conditions.
According to the test report, all test objectives were met. A final decision on equipment available to ground personnel to use is still pending until results are briefed to the AMC Operations Directorate.