Recently in Aerodynamics Category

I'll be the first to admit that there has been a distinct theme running through my posts this week. The newly flying 767-300ER with winglets just begs to be photographed. Here's the aircraft on its first flight in some very special air-to-air shots that really show off the new winglets. A very special thanks to Aviation Partners for the photos. (6 total, 3 after the jump)

The American Airlines 767-300ER, N389AA, outfitted with 11-foot tall Aviation Partners Boeing blended winglets, made its arrival at San Bernardino airport in sweltering Southern California, adorned with an experimental sticker below the one world logo. The aircraft will remain at San Bernardino for its two month FAA certification process.

Just broke:

Blended Winglets Make First Flight on Boeing 767-300ER

SEATTLE, July 21, 2008 /PRNewswire via COMTEX/ -- An American Airlines 767-300ER equipped with Aviation Partners Boeing Blended Winglets took to the skies for the first time at 1:50 p.m. central time Sunday July 20th. The newly modified aircraft flew a ferry flight from Kansas City, Missouri to San Bernardino, California where it will undergo two months of certification and winglet performance flight testing. The Blended Winglet installation, along with necessary wing and aircraft systems modifications, was performed by American Airlines employees at their Kansas City Maintenance Base.

Click for higher resolution expanded image

EXTRA: Listen to the IAG Podcast with Aviation Partners CEO Joe Clark

Imagine an improvement in aerodynamics that might just have the potential to transform aviation.

Joe Clark, CEO of Aviation Partners, believes he's got just the thing.

Spiroid tipped wing technology has the potential to save airlines a lot of fuel. Rather than the blended winglet, which has become the standard for all new Boeing 737s coming off the line, a Spiroid tipped wing differs by curving over to create a loop at the end of the wingtip.

According to Aviation Partners, "The Spiroid eliminates concentrated wingtip vortices, which represent nearly half the induced drag generated during cruise."

The technology isn't new. In fact, Dr. Louis Gratzer, Vice President of Technology for Aviation Partners has held the patent on the Spiroid tipped wings since 1992. When the winglets first flew on a Gulfstream II, Aviation Partners yielded a 10% improvement in fuel burn.

In a short-haul environment, a 10% improvement with Spiroid tipped wings could be the stepping-stone to the next-generation in fuel efficiency.

For example, the new Pratt & Whitney Geared Turbofan has touted a 12-15% improvement in SFC (specific fuel consumption). Pratt & Whitney has always affirmed that the 12-15% improvement is separate from whatever gains in efficiency are delivered through aerodynamic refinement of the aircraft.

The coupling of these two technologies could deliver fuel burn improvements up to 22-25%, exceeding even the most optimistic of forecasts without radical changes in engine technology or aircraft configuration that might be required with an unducted fan or blended wing body for example.

From an aerodynamic standpoint, Clark added that the Spiroids are compatible for any swept wing aircraft. Testing on a Falcon 50 will begin in 3-4 months to further validate the technology.

"We need to get out and do the full flight test realm. We don't know what they are going to do in icing and in flutter," said Clark.

Following the Falcon 50 Spiroid flight tests later this year, Clark wants to test the technology on a Boeing 777. On the longer-range 777s, this would require the removal of the raked wing tips. Boeing's raked winglets provide a 5.5% improvement in fuel burn over the original 777-200/200ER/300 aircraft.

Boeing has estimated that for every 1% improvement in fuel burn, the 777 would gain 75 nm in range, 10 more passengers or 2,400 pounds of cargo.

A doubling in wingtip efficiency with Spiroids could open the door for new routes for airlines. The famed 'Kangaroo Route', the non-stop flight between Sydney and London could finally be in reach. The 777-200LR is able to make the journey one-way, but the route has never been economically viable because of the prevailing winds that limit payload capacity. A 4.5% improvement in fuel burn could, once and for all, open up the route.