LONDON — The U.S. Air Force is trying to identify a spare C-130J Hercules to allow the cargo aircraft’s maker, Lockheed Martin, to flight-test a series of fuel-reduction trials that could cut consumption by up to 7 percent, according to a senior company official.
The U.S. plane maker has carried out wind tunnel testing on various drag-reduction options on the C-130, and is looking to validate those findings in flight, said Jim Grant, vice president for new business at Lockheed Martin Aeronautics.
With spiraling costs putting fuel efficiency high on the military’s agenda, the U.S. Air Force is looking at measures to reduce the huge fuel bill run up by its transport fleet. Lockheed also is doing work on the C-5 Galaxy, another transport plane.
Grant said guide vanes, strakes and winglets were all being looked at as part of a joint initiative with the service to cut fuel consumption across its air transport fleet.
“Wind tunnel tests have told us we have easily a 5 to 7 percent savings on fuel,” he told reporters during a briefing here April 11.
“We want to verify what we have seen in the wind tunnel, test the value of each of these options and see which ones really buy their way onto the aircraft in fuel saving versus cost” of doing the modification, he said.
Grant said the company is not under contract to undertake the modifications for the Air Force, but he expected some of the changes to “start occurring within the next year.”
But first, the company needs an aircraft to test some of its options. The current heavy use of the C-130J fleet makes it challenging to get an aircraft for the 30 days needed to modify and carry out the tests, Grant said.
“Everybody is using their aircraft heavily now,” he said. “It’s a huge challenge; the Js are very busy and it’s difficult to pull an aircraft for any significant length of time.
“The customer will decide what he wants. I’m not sure the winglets will be the most efficient; it could be something else,” Grant added.
With tactical aircraft such as the C-130, micro vanes might be the first change, he said.
Code One, Lockheed’s house magazine, said in March that the micro vanes had been tested on a new Canadian C-130J straight off the production line in Marietta, Ga.
At long-range cruise speeds, drag reduction equated to a savings of about 25 gallons an hour, according to Code One.
By comparison, a wind tunnel test of 5-foot-high winglets reduced fuel consumption on a typical 2,500-nautical-mile mission by about 21 gallons an hour.
The analysis is being done on the latest J model of the C-130, but the aerodynamic changes are applicable to other Hercules models as well.
Britain’s Rolls-Royce is working on an upgrade to the T56 turboprop engine used on older versions of the Hercules, with the aim of cutting fuel consumption or producing more power.