CHARLESTON AIR FORCE BASE, S.C. –
The Air Force's premier airlifter, the C-17, weighs in at a hulking 138.5 tons, and with cargo onboard, approximately 100 tons of fuel are needed to move the massive machine along a nine-hour mission.
Consuming enough fuel in one trip to gas up more than 1,000 sport utility vehicles, C-17s and the pilots who fly them are caught between missions versus money.
With as much as $4.2 billion spent annually on fuel throughout Air Mobility Command, the AMC Fuel Efficiency Office and Charleston AFB are fighting to keep fuel costs down, pound for pound - fewer pounds of fuel, for pounding out the mobility mission.
At Charleston AFB, a heavyweight of a project is out to settle part of the score and is estimated to save the Air Force $9 million annually. The project involves optimum profile descents for the C-17 and is overseen at Charleston AFB by Maj. Daniel Rohlinger, the fuel conservation point of contact for the 437th Airlift Wing, in coordination with the Federal Aviation Administration and Delta Air Lines.
The project boils down to streamlining the way the C-17 lands at Charleston AFB, said Major Rohlinger.
"We're developing arrivals where we can come in at idle the whole time, at the very minimum power setting, burning the least amount of gas all the way in, and then land," he said. "There's a few of them in civilian fields right now, and Charleston is the test bed for trying to get the military and civilians all working together."
The project also includes developing ways for the aircraft to gain altitude faster on takeoff, resulting in fuel savings as well.
To increase efficiency even further, reducing the amount of fuel onboard decreases the weight of the aircraft. The decrease in weight means decreased fuel consumption.
Although fuel efficiency is the name of the game, it can be a dangerous game to play if a pilot needs fuel he or she doesn't have, said Capt. Nathan Phillips, 15th Airlift Squadron chief of standardization and evaluation.
For pilots, there are two options - have more than enough to get there, or know exactly how much it will take.
Choosing the first comes at a cost. By adding just 10,000 more pounds of fuel, it requires 300 pounds per hour in fuel consumption to carry it.
Choosing the second option saves money, but is more difficult, said Captain Phillips.
Charleston AFB has the largest fleet of C-17s in AMC, and they don't all burn the same amount of fuel. Computing the efficiency of each requires collecting a large amount data over enough time to establish accurate figures.
"The [civilian] airlines have been doing this forever," said Major Rohlinger. "They know what every single tail of every aircraft burns specifically. If there is a certain average that an aircraft is supposed to burn, they know if one burns three percent more ... we're trying to get to the point where we know what each airplane will burn every time it flies. That would be the most efficient way to do it."
At Charleston AFB, the process to acquire the enormous amount of data is currently in effect, said Captain Phillips.
In his unit, tracking fuel usage is an everyday practice. When a pilot returns from a mission, a form completed via the internet is used to track the quantity of fuel used. If an amount is in deviation to the pre-calculated amount, additional fields are completed to justify the consumption of extra fuel.
Although the process can be painstaking and precise, Captain Phillips said it is an important process which demands attention to detail, and he works to ensure data is entered as accurately as possible.
"The entire Air Force is out trying to think of ways to save gas and in effect save money," said Major Rohlinger. "If you say you don't care about fuel savings, the next time you find yourself wishing that the airplane had something new or did something better, remember that wasted [money] that could've been spent on aircraft improvements."