Winglets

Owners, or potential owners, of the Hawker 800A’s and 800XP’s currently have the option of adding blended winglets to their private jet. This upgrade has been available since late 2004, during which more than 65 Hawkers have been modified. Many ultra-long-range and commercial jets now come standard with winglets -- but what exactly are the benefits of adding blended winglets to a private jet?

The main function of blended winglets is to reduce drag. Admittedly, drag reduction is probably not foremost on the minds of private jet owners, but it is an extremely important point. Reducing drag increases speed and decreases fuel consumption, thereby extending range and saving money.

Although the winglets cut operating costs, some owners shy away from the modification because of the initial expense of adding the winglets: the process takes three weeks and costs $438,000. The winglets improve the performance of the private jet and cut down on operating costs, which saves money – but how much money would really be saved by adding the winglets?

To begin with, Hawker 800’s with blended winglets burn on average 7% less fuel than their straight-wing counterparts. The Hawker 800 without winglets burns about 250 gallons per hour. With winglets, the Hawker 800 would consume only 232.5 gallons per hour, saving 17.5 gallons for each hour of flight time. Fuel currently costs $3.80 per gallon, which works out to a savings of $66.50 saved for every hour in the air. At this rate, it would take 6,628 hours of flight time to match the cost of adding the winglets.

....to read the complete article, see our January Private Jet Buyer's Guide at: http://www.jetadvisors.com/articles/2007-1-winglets.htm

The Winglet Option

You may have noticed that an increasing number of commercial and private jets are adding winglets as a standard feature. Winglets are nothing new -- the first winglets appeared on the Learjet 28 in 1977 -- but they have only become ubiquitous on jets in the past few years. Many private jets on the market today offer the option of adding winglets at the time of building, or later as a retrofit option. Adding winglets can be fairly costly: retrofitting a Hawker 400XP takes three weeks and costs $438,000.

So, what do winglets really do? And are they worth it?

Winglets are designed to decrease the wingtip vortices that develop at the tip of a wing. These vortices develop as the high pressure air from beneath the wing meets the lower pressure air from above the wing. To get a better idea of what the interaction ofthe high- and low-pressure air looks like, take a look at the picture below, taken from a NASA study on wingtip vortices:

Winglets serve to reduce the severity of the induced drag created by these vortices, which has a myriad of side benefits. Reduced drag translates into faster cruise speeds, a lower fuel burn, and an increased range. The winglets also add stability in flight, which is particularly noticeable in small aircraft susceptible to turbulence.

The payoff for adding winglets to a jet is subtle, but an increasing number of private jet owners agree that the cost is more than justified by the benefits.

for more information on winglets and a detailed cost-benefit analysis of the retrofit, visit this site: http://www.jetadvisors.com/articles/2007-1-winglets.htm

for more information on the NASA research on winglets, visit this site: http://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-15-DFRC.html