The US Air Force (USAF) is testing new drag-reducing finlets that could improve fuel efficiency and operating range for the service’s Lockheed Martin C-130J transports.
Developed by Seattle-based Vortex Control Technologies (VCT), the finlets are estimated to reduce a C-130J’s drag by 6-8% by reshaping airflow around the aft fuselage to improve pressure distribution and reduce flow separation.
VCT holds a patent on the finlet concept, which uses an array of small fins mounted on the lower portion of the aft fuselage.
The company pioneered the technology for the commercial aviation industry, partnering with airlines including Delta, Avelo and Lufthansa-Turkish Airlines joint venture SunExpress.
VCT was selected by the Pentagon to develop efficiency solutions for several USAF platforms, including C-130Js, Boeing KC-135 tankers and Boeing C-17 airlifters.
On 23 July, the air force revealed it has begun flight testing the finlet technology aboard an Air Force Special Operations Command MC-130J at Eglin AFB, Florida.
The MC-130J is a specialised variant of the four-engined C-130J used for long-range insertion, extraction and aerial refuelling.
“Drag reduction initiatives like finlets are a tangible way we can modernise our fleet, reduce costs and increase combat capability,” says Roberto Guerrero, deputy assistant secretary of the air force. “Every gallon of fuel saved extends our operational reach and enhances readiness in contested logistics environments.”
The initiative will support the USAF’s mission of delivering air power “anytime, anywhere”, Guerrero adds.
According to the air force’s 417th Flight Test Squadron, the goal of the flight-test campaign is to determine the airworthiness of the 3D-printed finlets, which were mounted on the outer hull of the MC-130J’s rear cargo door and on both sides of its vertical stabiliser.
“Air crew and engineers will analyse the finlets’ flight and air-handling qualities as well as the aircraft’s airdrop compatibility with the new additions,” the USAF says.
After the initial flight at Eglin, the air force plans to continue the finlet trials at its main test centre of Edwards AFB, California. That portion of the campaign will include multiple air drop evaluations, a key capability for C-130Js.
The standard configuration of the turboprop airlifter is used for dropping troops and cargo via parachutes into remote terrain.
The air force plans to eventually roll out finlet technology on its entire C-130J fleet, not just speciality variants like MC-130Js.
Finlets being installed on an MC-130J
