Defense

October 12, 2012

‘Vortex surfing’ could be revolutionary

The view from a C-17 cockpit while trailing behind another C-17 during the first tests of “vortex surfing” at Edwards Air Force Base, Calif., Oct. 2, 2012. Early indications from the tests promise a reduction of fuel consumption by up to ten percent.

Migrating birds, NASCAR drivers and Tour de France bicyclists already get it. And now the Air Force is thinking about flying gas-guzzling cargo aircraft in formation – ‘dragging’ off one another – on long-haul flights across the oceans.

Flight tests with C-17s “vortex surfing” at Edwards Air Force Base, Calif., Sept. 6 and Oct. 2, have demonstrated potentially large savings of fuel and money by doing what geese do naturally. Tests show that flying in formation might be smarter than flying alone for Airmen, and not just for birds.

As one effort in the Air Force drive to reduce its overall fuel consumption, vortex surfing may be the wave of the future.

“The concept, formally known as Surfing Aircraft Vortices for Energy, or $AVE, involves two or more aircraft flying together for a reduced drag effect like what you see with a flock of geese,” said Dr. Donald Erbschloe, the Air Mobility Command chief scientist.

A series of test flights involving two aircraft at a time, allowed the trailing aircraft to “surf” the vortex of the lead aircraft, positioning itself in the updraft to get additional lift without burning extra fuel.

Early indications from the tests promise a reduction of fuel consumption by up to 10 percent for the duration of a flight. Over long distances and with even a small fraction of Air Mobility Command’s average of more than 80,000 flights a year, the fuel and cost savings could reach into the millions of dollars, experts say.

Next up: The Air Force Research Laboratory will analyze the data from for possible applications to other aircraft on a variety of missions.

Dr. Erbschloe said larger air mobility aircraft like the C-17 can fly in formations that are potentially easy to maintain and which do not require the planes to be exceptionally close together.

“The test flights were flown at longitudinal separations of 4,000 or greater,” said William Blake, one of the key developers of $AVE at the AFRL.

According to AFRL officials, modified C-17 formation flight system software enabled precise auto-pilot and auto-throttle systems to ensure the trailing aircraft achieved and maintained proper flight position without active assistance from pilots.

“The autopilot held the position extremely well — even close to the vortex,” said Capt. Zachary Schaffer, an aircraft commander on one of the test flights. “The flight conditions were very safe; this was as hands-off as any current formation flying we do.”

The first C-17 flight tests employing “vortex surfing” were conducted at Edwards Air Force Base, Calif., Sept. 6 and Oct. 2, 2012. Surfing Aircraft Vortices for Energy, or $AVE, involves two or more aircraft flying together for a reduced drag effect to save fuel.

Other pilots found differing levels of ride quality and discovered some flight test points might be difficult for long-endurance flights.

“The key will be finding the right balance of quality for improving fuel efficiency and ride,” said Maj. Eric Bippert, another aircraft commander on one of the test flights.

Bippert said being a part of the test program with so many talented engineers was a remarkable experience, and the concept could eventually impact global air transportation, overall.

“AMC has done really well with fuel efficiency at the operational level,” said Erbschloe. “The command has worked to gain efficiencies from the ‘low-hanging fruit’ such as optimizing flight routing, reducing weight where possible, and by not carrying excess fuel. $AVE offers significant efficiency gains, if employed in concert with these initiatives.”

He said early indications show the tests meet AMC criteria of the concept regarding safety and minimization of aircrew and aircraft strain while also being operationally sensible with a viable return on investment.

“AMC consumes 20 percent of the fuel used by the overall federal government, so we’re constantly looking for pragmatic ways to improve our fuel efficiency,” said Erbschloe.

“Assured energy advantage for our Air Force is only possible through revolutionary energy initiatives like $AVE,” said Dr. Mark Maybury, Air Force chief scientist, upon hearing the results of the tests.

The $AVE concept was previously highlighted in the 2011 Energy Horizons study, sponsored by the Secretary of the Air Force and chaired by Maybury.

The tests were the culmination of an ongoing, combined effort between AMC, the AFRL, the 412th Test Wing, the Air Force Life Cycle Management Center, the Defense Advanced Research Projects Agency, the Boeing Company and NASA Dryden Flight Research Center.

 




All of this week's top headlines to your email every Friday.


 
 

 

Headlines October 24, 2014

News: U.S., South Korea delay transfer of wartime control - The U.S. and South Korea have delayed transferring wartime operational control of allied forces by taking on a “conditions-based approach” and scrapping the previously set deadline of 2015.   Business: Exclusive: Lockheed, Pentagon reach $4 billion deal for more F-35 jets - Lockheed Martin and U.S. defense...
 
 

News Briefs October 24, 2014

French moving troops toward Libyan border A top French military official says the country is moving troops toward the Libyan border within weeks and, along with U.S. intelligence, is monitoring al Qaeda arms shipments to Africa’s Sahel region. A French base will go up within weeks in a desert outpost just a hundred kilometers (60...
 
 
Navy photograph

Navy to commission submarine North Dakota

Navy photograph The PCU North Dakota (SSN 784) during bravo sea trials. The crew performed exceptionally well on both alpha and bravo sea trials. The submarine North Dakota is the 11th ship of the Virginia class, the first U.S....
 

 

Boeing announces SF Airlines order for Boeing converted freighters

Boeing announced Oct. 23 that SF Airlines has placed an order for an undisclosed number of 767-300ER passenger-to-freighter conversions (Boeing Converted Freighters). SF Airlines, a subsidiary of Shenzhen, China-based delivery services company SF Express, will accept its first redelivered 767 in the second half of 2015. “SF Express aims to become China’s most respected and...
 
 
LM-C130

Another Super Herc Little Rock Rollin’

  Lockheed Martin delivered another C-130J Super Hercules to the 61st Airlift Squadron at Little Rock Air Force Base, Ark., Oct. 23. Little Rock AFB’s new C-130J was ferried from the Lockheed Martin Aeronautics facility ...
 
 

United Technologies beats third quarter profit expectations

United Technologies Corp. Oct. 23 reported third-quarter profit of $1.85 billion as sales increased across all its businesses and the aerospace giant reported favorable tax settlements. The Hartford, Conn.,-based company said it had profit of $2.04 per share and earnings, adjusted for non-recurring gains, came to $1.82 per share. The results topped Wall Street expectations,...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>