at777
Posts: 97
Joined: Sat Aug 05, 2006 8:36 am

Question About Winglets

Mon Jul 21, 2008 10:47 pm

Lately (4-5 years) airlines have been applying winglets on their planes. We all know that winglets add fuel economy. With the way fuel costs are and they look like they are not going to go down any time soon, is it possible to put winglets on the horizontal stabilizers somehow? I know it might sound funny or look funny, but if they help on the wings, can they not help on the stabilizers? This is just something I have been thinking about for the past couple of weeks now.

Ashley in CLT
 
EMBQA
Posts: 7798
Joined: Sat Oct 25, 2003 3:52 am

RE: Question About Winglets

Mon Jul 21, 2008 10:51 pm



Quoting AT777 (Thread starter):
is it possible to put winglets on the horizontal stabilizers somehow?

No.... is does not added benefits by doing so.
"It's not the size of the dog in the fight, but the size of the fight in the dog"
 
kcrwflyer
Posts: 2535
Joined: Tue May 18, 2004 11:57 am

RE: Question About Winglets

Mon Jul 21, 2008 10:59 pm

The B1900D has them, but I think thats more of a stability thing due to using the same tail as the Kingair.
 
EMBQA
Posts: 7798
Joined: Sat Oct 25, 2003 3:52 am

RE: Question About Winglets

Mon Jul 21, 2008 11:14 pm

Quoting KcrwFlyer (Reply 2):
The B1900D has them

Not really the same. Those are way inboard of the tip and only added because of the changes from the C model to the D model due to the raised roof. Beech had two option....1) a total redesign of the tail... or 2) add the strakes on the tail and deliver faster. Like you said, it was for stability reason due to the air flow over the raised roof on the D.

[Edited 2008-07-21 16:16:58]
"It's not the size of the dog in the fight, but the size of the fight in the dog"
 
AA737-823
Posts: 4905
Joined: Wed Mar 01, 2000 11:10 am

RE: Question About Winglets

Tue Jul 22, 2008 12:29 am

Because the H-tail doesn't provide the primary lifting force, it wouldn't add benefit. There's no point in increasing the efficiency of a wing that barely flies in cruise.
Further, any right angles you make create vortices. This is true even of blended winglets- they're very small, and that's why the blended technology was developed, but they're still present.
On the main wing, this minor addition of drag is more than overcome by the improved efficiency of the airfoil, hence a 5-6% reduction in fuel burn.
But on the tail, it wouldn't be so.
So, in conclusion, you'd be adding drag to a wing that doesn't require any improved lifting efficiency.

In the future, you might have more luck posting items like this in the 'tech-ops' forum. That way, you cater to a more... cough, knowledgeable base of folk.
Flame on, folks.
 
at777
Posts: 97
Joined: Sat Aug 05, 2006 8:36 am

RE: Question About Winglets

Tue Jul 22, 2008 1:22 am

Yeah I just got the email about it being moved to this forum. That's my bad.
Thanks for all the feed back.
 
aeroweanie
Posts: 1577
Joined: Fri Dec 03, 2004 9:33 pm

RE: Question About Winglets

Tue Jul 22, 2008 4:39 pm

Winglets work by reducing the induced drag of a lifting surface. The penalty is that they increase the parasitic drag.

Induced drag increases by the square of the lift load on the surface. Horizontal tails don't carry much load in cruise flight, so they don't generate much induced drag. A winglet on the horizontal tail would then just increase the parasitic drag. Hence, winglets wouldn't do any good on a horizontal tail.

The Beech 1900 has the things hanging down from the horizontal tail to add directional stability. The 1900 was created by stretching a King Air 200, including using the tail with minimum changes. The aircraft was found to need more longitudinal and directional stability, so the horsals and little verticals were added to address each issue respectively. I should note that the 1900 also has a different inboard wing and nacelle than the King Air 200.

1900C and 1900D:

View Large View Medium
Click here for bigger photo!

Photo © Md Faridz
View Large View Medium
Click here for bigger photo!

Photo © Art Brett - Photovation Images

 
AA737-823
Posts: 4905
Joined: Wed Mar 01, 2000 11:10 am

RE: Question About Winglets

Wed Jul 23, 2008 11:54 am



Quoting AeroWeanie (Reply 6):
Induced drag increases by the square of the lift load on the surface. Horizontal tails don't carry much load in cruise flight, so they don't generate much induced drag. A winglet on the horizontal tail would then just increase the parasitic drag. Hence, winglets wouldn't do any good on a horizontal tail.

Your post was more concise, more eloquent, and more correct than mine... nice job.

Quoting AeroWeanie (Reply 6):
The 1900 was created by stretching a King Air 200,

Indeed, and the -200 by stretching the -90, although it got a new tail.

Who is online

Users browsing this forum: No registered users and 7 guests