The US Air Force (USAF) is to begin the final phase of C-17 Globemaster III drag reduction testing.

A team at the 418th Flight Test Squadron (FLTS) has been working on the Air Force Research Laboratory’s C-17 drag reduction programme for the past year.

The programme involves testing the aircraft parts in various configurations to see if the external structure modifications can improve airflow around the airplane.

418th FLTS project engineer Bogdan Wozniak said: “A 1% improvement in drag reduction will result in 7.1 million gallons of fuel reduction per year.

“1% to 2% drag reduction could translate to $24-48m dollars in fuel savings per year.”

Personnel at the 418th FLTS are considering using 3-D printed parts by Lockheed Martin to complete testing of the fifth and final configuration.

The aircraft will keep 12 microvanes and six total fairings with the addition of two fairings on each winglet, the USAF said in a statement.

Wozniak further added: “Aircraft and atmospheric data are collected with the aircraft flying straight and level at a constant airspeed and constant altitude with low winds and low air turbulence at 90 degrees to the wind to mitigate head and tailwind effects.

"A 1% improvement in drag reduction will result in 7.1 million gallons of fuel reduction per year."

“Each flight at a constant airspeed and altitude requires eight hours to acquire sufficient data for the analysis.”

The Boeing C-17 will also undergo airdrop tests in December to ensure that the microvanes do not interfere with the aircraft's airdrop mission.

This four-engine, T-tailed military transport aircraft can carry large equipment, supplies and troops.


Image: The C-17 Globemaster III used for all five test phases is provided by Joint Base Lewis-McChord, Washington. Photo: courtesy of US Air Force photo / Kenji Thuloweit.