Talk:Leading-edge cuff

message: Some article text was copyed from this book ;</br>
"Leading edge cuffs are a ...device to modify the airfoil used. This (drooped leading edge) has effect of causing the airflow to attach better to the upper surface of the wing at higher Aoa, thus lowering stall speed. A secondary benefit is to produce a more gentle stall onset, particularly when the original airfoil had a sharp leading edge shape."
:The author did not well undersand the aerodynamic action of a modified outboard leading edge : outboard cuffs are used to modify not the airfoil but the wing flow ; that is not a 2D (airfoil) improvement but a 3D matter (vortex lateral control of spanwise separated flow). Chambers comments : "that stall is really a 3 dimensional issue, not just 2-D airfoil stuff!".
:"Gentle stall onset" is not a "secondary benefit", it is the very objective of the Nasa program. The author seems do not know that an asymmetric stall is much more dangerous than a high stall speed. 
:Drag penalty section was also copyed from this book, in disagreement with Nasa report. Plxdesi2 (talk) 10:23, 29 April 2013 (UTC)
thread_title:  Aviation Management : Global Perspectives 

message: "...a more gradual and gentler stall onset, particularly where the original airfoil had a sharp leading edge shape.  
:The aircraft (Questair Venture) given in the Cox paper has a Naca 23012 rounded nose airfoil, different from a "sharp leading edge shape". This shows again that outboard stall/spin matter is not only an airfoil (2D) issue. Plxdesi2 (talk) 12:01, 29 April 2013 (UTC)
thread_title: ...sharp leading edge shape

message: According to K. C. Khurana book extract in the article :</br>
"In the case of the modification of the AA-1 Yankee to the AA-1A Trainer the loss of cruise speed amounted to 8 knots or 7%, which is not uncommon."
:AA-1 Yankee cruise speed is 125 mph. With a 8 kt (9 mph) loss of speed, the power penalty is (125 / 116)^3 = 1.25 that is 25 % ! (or a bit less because induced drag decreases with speed). The author confused delta V with delta drag (1.07). In fact delta V is about 2 %, as (1.023^3 = 1.07). 
:"which is not uncommon" : no examples given. Nasa/other reports give a loss of speed about 1 - 2 %
:It seems that this kind of false information, not sourced, not corrected, is more of a concern than J. Chambers post reliability. Plxdesi2 (talk) 16:56, 29 April 2013 (UTC)
replies: text: In the 8 august 2009 revision, following Erik9bot [Category:Articles lacking sources] request, the added reference [3]  about AA-1 did not quoted the book from which the text was copied out, and did not contain a single word on the subject (cuff drag penalty) either, contravening [WP:IRS] : "Sources should directly support the information as it is presented in an article". Plxdesi2 (talk) 09:31, 30 April 2013 (UTC)
thread_title:  Drag penalty - Khurana  

message: "Where a factory modifies an existing design by the addition of a leading edge cuff it is often due to an identified problem or deficiency in the original airfoil used. One example of this is the American Aviation AA-1 Yankee, which was modified with the addition of an outboard leading edge cuff to become the AA-1A Trainer. This was a result of flying schools operating the Yankee demanding a lower approach speed and gentler stall characteristics from the manufacturer.[21][22][23]"
:The AA-1 is not "one example of this", because it was not modified by the factory (1968-1978), but later by Nasa experimenters (1979 and later). 
:The AA-1 Trainer is a 1971 model, of course without outboard leading edge cuff, see ref [21]. 
:The [21][22][23] references are general papers about the aircraft (description, handling qualities) but do not describe "flying schools demanding a lower approach speed and gentler stall characteristics" from manufacturer or Nasa stall/spin program team. 
:As for "Drag penalty - Khurana", that is a full-copied, unverified, uncorrected and misquoted information. Plxdesi2 (talk) 10:10, 30 April 2013 (UTC)
thread_title: Applications

message: Hello fellow Wikipedians,
I have just modified one external link on Leading edge cuff. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
*Added archive https://web.archive.org/web/20090726160241/http://www.cessna.com/single-engine/cessna-400/cessna-400-features.html to http://www.cessna.com/single-engine/cessna-400/cessna-400-features.html
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
Cheers.—InternetArchiveBot (Report bug) 21:34, 24 January 2018 (UTC)
thread_title:  External links modified (January 2018)