Winglets

silver-eagle

silver-eagle

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If I understand the concept correctly, the use of vertical winglets increase the effective length of the wing. Why is it you don't see winglets on most small planes? Wouldn't it improve the overall handling and the slow speed characteristics?
 
Here's a pretty good informational piece on winglets...

http://www.b737.org.uk/winglets.htm

As an example, here's their bit on just adding winglets to a 732...

This is a 737-200Adv, L/N 628, fitted with mini-winglets. This is part of the Quiet Wing Corp flap modification kit which gained its FAA certification in 2005. The package includes drooping the TE flaps by 4 degrees and the ailerons by 1 degree to increase to camber of the wing. Benefits include:
  • Payload Increase of up to 5,000 lbs.
  • Range Increase up to 3%
  • Fuel Savings up to 3%
  • Improved Takeoff/Landing Climb Gradients
  • Reduced Takeoff/Landing Field Length
  • Improved High Altitude Takeoff/Landing Capability
  • Improved Hot Climate Performance
  • Reduced Stall Speeds by 4-5kts
Click to expand...
Those are some pretty good benefits over the long-term.
 
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silver-eagle said:
If I understand the concept correctly, the use of vertical winglets increase the effective length of the wing. Why is it you don't see winglets on most small planes? Wouldn't it improve the overall handling and the slow speed characteristics?
Click to expand...

Note that the article reference says:
"They are 8ft 2in tall and about 4 feet wide at the base, narrowing to approximately two feet at the tip and add almost 5 feet to the total wingspan."

As they effectively increase the wingspan, this statement is slightly misleading. If they are 8'2" tall and they add 5 feet to the actual wingspan, I interpret this to mean they extend 2'6" beyond the normal wingtips. Adding the 8'6" height would extend the actual wing horizontally by about 10', for a total effective increase of 20' to the total wingspan. One of the advantages of raising the extension vertically is that the aircraft can continue to use the same ramp space. If the extension were horizontal, many airports would have to change where the aircraft could taxi and the gates that could service them.
 

Attachments

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KennyFlys said:
It doesn't quite seem to be the same document but one of the players is the same. How well do you understand engineering?

The attached should be taken in moderate doses.

Also an interesting read...
http://www.aviationweek.com/aw/gene...iciency Driving Winglet Retrofits&channel=mro
Click to expand...
It appears to be the complete report. Written in 1980, the intro is rather funny. "The current rising cost of fuel has led to increased research on methods for increasing f u e l efficiency f o r all categories of aircraft."
So, if there are so many benefits for winglets, how come we don't have Lopresti or Knots2U building them for our Pipers? I could use a 6 knot increase.
 
silver-eagle said:
It appears to be the complete report. Written in 1980, the intro is rather funny. "The current rising cost of fuel has led to increased research on methods for increasing f u e l efficiency f o r all categories of aircraft."
So, if there are so many benefits for winglets, how come we don't have Lopresti or Knots2U building them for our Pipers? I could use a 6 knot increase.
Click to expand...

The efficiency of winglets increase with speed. Putting winglets on small GA planes are about the same as putting on a 3 bladed prop versus a 2 bladed, it looks cool but doesn't really help performance.

I flew the Boeing 727 with the Dugan Modification which put winglets on. In my opinion the plane flew like crap after the conversion, but it did have a slight speed benefit.

I also owned a Piper Navajo with the Panther conversion which included winglets and it made the ailerons stiffer. As far as increased speed once again I found it negligable.

The 337 Skymaster has an STC for winglets and from my research any benefit is negligible, but they will reduce the weight of your wallet significantly. :wink2:
 
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And the preformance can be modeled using the method of moments. The engineers amongst us will understand... :devil:
 
Rotor&Wing said:
The 337 Skymaster has an STC for winglets and from my research any benefit is negligible, but they will reduce the weight of your wallet significantly. :wink2:
Click to expand...

Thereby increasing the available usefull load!!!:goofy:
 
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