AT777 From United States of America, joined Aug 2006, 187 posts, RR: 0 Posted (4 years 11 months 3 days 1 hour ago) and read 2270 times:
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.
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 From United States of America, joined Mar 2000, 5381 posts, RR: 11 Reply 4, posted (4 years 11 months 2 days 23 hours ago) and read 2162 times:
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.
AeroWeanie From United States of America, joined Dec 2004, 1601 posts, RR: 52 Reply 6, posted (4 years 11 months 2 days 7 hours ago) and read 2025 times:
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.
AA737-823 From United States of America, joined Mar 2000, 5381 posts, RR: 11 Reply 7, posted (4 years 11 months 1 day 12 hours ago) and read 1919 times:
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.