Talk:Leading-edge droop flap

Title

Is this the same thing as the Leading edge droop described at Flap (aircraft)#Types of flaps, or a droop flap? Also droop without qualification could apply to an aircraft's droop-nose, or a droop wing as on the North American XB-70 Valkyrie. Thanks. - BilCat (talk) 00:27, 7 March 2014 (UTC)

To answer the first question: yes it is. As for the second, everywhere I have seen the term before researching it today, they are just called "droops". I wasn't aware of their use on the A380 until today and Airbus' official name seems to be "droop nose". I edited the dab page Droop to contain a link to this article before I even created it, and to droop-nose; and we can put a hatnote on have added a hatnote to droop-nose. Neither Leading edge droop, Leading-edge droop, droop wing, wing droop or their various capitalisations have any incoming links. YSSYguy (talk) 01:34, 7 March 2014 (UTC)

Ok, thanks. I honestly don't know the proper terms, but "droop" alone seems ambiguous, and its use in the sources almost a type of jargon. As to Airbus calling something on a wing a "drop nose", it must lose something in translation, as it certainly has a different connotation to someone who speaks standard English such as myself. :) - BilCat (talk) 02:21, 7 March 2014 (UTC)

I agree it's jargon, which is why I created the article - I saw it used in three of four articles with no explanation whatsoever of what a droop is or what it does. As for Airbus, apparently part of the reason the Trident's droop design was used is because Airbus could use it and couldn't use something else designed by an aircraft manufacturer not-a-million-miles-away from you in the northwest corner of the US; which may have something to do with the name. YSSYguy (talk) 02:42, 7 March 2014 (UTC)

Ah! Gotcha. Go Seahawks. - BilCat (talk) 03:47, 7 March 2014 (UTC)

The cited flight piece describes them as "droop sections" and refers to "droop" alone only in terms of their geometric configuration when operated. I do not have access to the other source, but they are usually classed as "leading-edge flaps" (of which Krueger flaps are a slotted example). As such they might best be named here as "Leading-edge droop flaps". This is in accordance with other articles, which cite Gunston's dictionary, so I have moved the article accordingly. (Note that "Droop (aeronautics)" is far more general than these devices and is wholly unsuitable) — Cheers, Steelpillow (Talk) 10:53, 18 March 2020 (UTC)

The function of camber

The following sentence is used in the sub-heading Use and effect:

Droops function with other high-lift devices on an aircraft to alter the camber of the wing and provide more lift.

It is a very popular idea that increasing camber, extending flaps etc. provide more lift. Sadly, it isn't true. The lift generated by a wing is the weight of the aircraft multiplied by the load factor, plus an amount to cancel the download on the horizontal stabilizer. Whether the flaps are up or down or somewhere in between, and whether the airfoil is symmetric or cambered or variable, have no effect on the lift generated by the wing.

The purpose of using a cambered airfoil, and extending flaps and slats and droops, is to reduce the stalling speed. This is achieved by raising the maximum lift coefficient.

I don't have access to the source (Norris & Wagner) to see exactly what expression is used, but regardless of that, I suggest the sentence quoted above should be altered to say "... to alter the camber of the wing and reduce the stalling speed." Dolphin (t) 06:24, 7 March 2014 (UTC)

It's not in Norris, that was just me making a sweeping statement trying to put in layman's terms what devices do. I did WL to lift coefficient in that sentence, but please, make any changes you see fit. If you have a reference text, go hard sir - I was having trouble finding anything about droops on the interwebs. One thing I did find was a statement that droops were used on the wing root glove on the Tupolev Tu-22M swing-wing military aircraft because the sweep angle of the glove was too high for slats to be effective. It was literally a single sentence in a magazine article, barely more than a passing comment, so if you could find something to back up that slat use is limited by sweep angle, put that in the article too please. I know why droops are on the A380, but why are they used on other aircraft instead of slats or Kruegers? Dassault seems to be in love with them, so I for one would like to see more general reasons for and against using them discussed. Explaining why it's better for the inboard wing to stall first might be a good idea too - again I couldn't find anything on the internet. YSSYguy (talk) 14:17, 7 March 2014 (UTC)

I have made the change - my diff.

I associate droops with British aircraft - the Trident had them, and of course BAe designed and builds the wings of Airbus aircraft including the A380. It may be that RAE Farnborough did a lot of good research and produced a lot of good data on drooped leading edges whereas the US NACA produced a lot of good data on Krueger flaps and LE slats.

I will see if I can find a reference for wanting the stall to commence closest to the wing root and progress slowly outboard. Dolphin (t) 11:35, 8 March 2014 (UTC)

List of aircraft with droops - complete?

Can anyone confirm whether the list in the article is complete? And which is the source of that list? Thanks & regards, DPdH (talk) 12:41, 8 April 2014 (UTC)

Any additional images?

Dear editors, I think that a diagram showing location and functioning of the Droops would enhance this article. Can anyone please contribute one? Also it may be useful to show the Droops used in other aircrafts (e.g.: the HS Trident); I'll try to find appropriate images for this. Regards, DPdH (talk) 13:45, 8 April 2014 (UTC)

Forgot to mention that yesterday I added an image of the Trident 2 wing showing leading edge surfaces, with the intention to show the droops from closer distance, and based on the information of this wikiarticle that Early variants of the Hawker Siddeley Trident had two droops on the outboard of each wing.... The article in the Flight International issue of 29 June 1972, p.933 explicitly mentions the Trident 1 with this droops arrangement; if someone have verifiable evidence that the Trident 2 didn't have droops, please feel free to amend my edit. Kind regards, DPdH (talk) 11:22, 9 April 2014 (UTC)

Please note that user YSSYguy provided this accident report and the Staines accident report, both of which state that the Trident 2 had slats (the Staines report explicitly stating on PDF page 15 that the Trident 2 has slats in lieu of droops). Hence the pic I've added is irrelevant for this article; apologies for this. Will keep searching for appropriate images/diagrams. Regards, DPdH (talk) 11:50, 10 April 2014 (UTC)

Hatnote

@Ahunt: Droop Nose redirects here, and that term can also refer to the East Lancs 1984-style double-deck body. Thus a hatnote is necessary to direct readers to the correct article if that is what they are looking for. feminist (talk) 15:49, 5 February 2018 (UTC)

I see your point there, but the hatnote is excessively long. I think it would be better to make Droop Nose a disambiguation page. - Ahunt (talk) 16:00, 5 February 2018 (UTC)

Done. feminist (talk) 17:00, 5 February 2018 (UTC)

Thanks! Collaboration works! - Ahunt (talk) 18:09, 5 February 2018 (UTC)