Did I mention that the wallet was made of foreskin! Ewwwwww!

 

Who's?

 

The practical benefit of a foreskin wallet, of course, is that with a little rubbing it becomes a handy overnight bag.

 

We have a couple of our ETOPS 757s with winglets now. Management was reluctant even with our Hawaii routes to add them because the payoff was just over one year and they would not spend the money for anything without a payoff under a year. Stupid, but that's the new US Scareways, at least out West.

The mod is an extra 1500#s and the payoff is evident over 4 hours flight time. With fuel going up the savings grow larger.

We run cost index 60 to 65 which at the max weights we fly (almost every t/o is 235000 to 248000) gives you a 307 to 312 kt climb and descent and a cruise of .796 to .801.

I have seen no difference in max speed with the winglets.

Sorry for the thread correction, back to the Air Force stories!

 

In fact, yes, they did have to wait for the airplane to fly. End-plates or winglets were proven before first flight but the problem was the rigging, materials, etc created more drag than they eliminated and thus, were not used.

There are multiple solutions for dealing with the vortice. The endplate is a vertical treatment while the winglets include multiple angles.

This is a quick overview...
www.aoe.vt.edu/~mason/Mason_f/WingletsS04.ppt

First application on Longhorn Lears although concept first proven on USAF KC-135. Later tests using Continental DC-10 also not implemented.

Where you see 'endplates' today is on formula 1 and such.

 

There you go, 1897! Good find!

BTW - My sis was an AOE at VT, #1 grad in the whole College of Engineering when she graduated. I was also a VT engineer, but barely scraped by!

 

And I was an English Lit major LONG ago. I did some fairly extensive research into winglets a while back and was surprised also that the first concepts were actually well before first flight. Also the design of a winglet is specific in that it is targeted for a specific regime (ie m 0.80M) for its BEST performance. And as noted before, adding a winglet means essentially completely re-designing the wing but part of the equation is already fixed.. thus complicating the process. And a fair amount of the stuff out there is just that.. stuff.

The thing that amazes me is the same guy, Whitcomb, is the one who came up with the area rule fuselage. He said he spent time each day just pondering and one day's pondering was on bird wings. That gave him the idea for the winglets and he then his homework, did some extensive research (prior to the internet), found old papers and began the process. First tests on the KC-135 where actual savings exceeded estimates.

Aviation Partners has moved beyond the 'simple' winglet and is exploring the 'spiroid' which is a tip that continues into a full closed curve.

 

Spiroid? Would that be a CIA agent that is a tad "anal retentive"?

 

I'm not sure one can be a tad 'anal retentive'. But that's another subject...

here is the info on the AIRPLANE spiroid..

Aviation Partners Inc - The Future is on the Wing

Here's the image...


FWIW, back in the late 80s, early 90s, Lockheed floated a concept airplane that never got off paper. I think we talked about it on this forum but it was a 'ringwing' with a wing that was essentially a large ovoid and was attached to a large vertical fin for rigidity.

In this PDF, look at figure 16 and you will see the McDoug offering for an MD-80 with a 'ringwing'.

http://tinyurl.com/64jprh

 

Somehow, I get an image of a paper airplane model, and a bunch of engineers throwing it around.