Aces High Bulletin Board
General Forums => Aces High General Discussion => Topic started by: miko2d on October 10, 1999, 03:07:00 PM
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They opened automatically at the high andle of attack and or at low speed. They apparently were independent and could open assymetrically (one wing and not the other).
Anybody know how they were operated (air, hidraulic, mechanical) and where did they take their input - sensors (what kind?), computer, accelerometer, telepathy, etc.?
With so many dedicated LW craisies... er, fans around, somebody should know enough to shed the light on the details of the slats operation. May be HTC will even use that info in the future implementation (add slats to 109s but disable their rudder trim - he, he...).
Why were they not used more widely, and what other planes had them?
While you are at it, please tell me the difference bewteen regular flaps and the combat "butterfly" flaps used on the some of the japanese planes - design, shape, etc.
miko--
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Miko, the leading edge slats were held extended by a light spring action, and it is only air loads that retract them against the wing. At high angles of attack [at any airspeed, its angle of attack that counts] the slats extend and increase the camber of the wing [airfoil] thereby increasing the lift on that wing, very usefull in tight turns or on slow landing approachs[high angle of attack] also on takeoff, when added lift is a good thing. The British seemed to like slats more than other nations at the time. On the downside, slats require adjustments, are prone to damage, add dreaded weight, and can be deadly if they operate incorrectly or stick in the wrong position on one wing only. As wing designs improved, the downside of slats made them unecessary and not worth the bother. Keep Flyin!
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RE: Standard-v- Butterfly flaps.
Standard Flaps - take a look at the P51. The flap is merely a control surface which angles down when activated, changing the camber of the airfoil but not changing the overall wing surface area.
Butterfly Flaps - now imagine a flap which is partially hidden within the wing itself. When the flaps are actuated, they first extend backwards from the wing (increasing overall wing area) and then angle downward (changing the camber of the airfoil. Increasing the effective wing area of course decreases the effective wing loading, enabling the aircraft to be more maneuverable at low airspeeds.
Next time you're in a modern jet airliner, take a look at the flaps when they deploy. You'll see that the flaps first extend backwards out of the wing, and then droop downwards. A modern version of the butterfly flap.
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C.O. Phoenix Squadron
www.users.bigpond.com/afinlayson/index.htm
'feel the heat .......'
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Jekyll,
I think that those type of flaps (butterfly)are refered to as "Fowler" type flaps. I think the only WWII warbirds that used them were the P-38s. At least as far as US iron is considered, I don't recall any of the other nations using them. They are very effective but complicated and heavy.
Sharky
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Yep you are describing Fowler flaps.
BTW the Me 262 has the same type of slat system as the Me 109. I verified this once manually. I pushed the left slat up and it sprang right back. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Flacke:
"As wing designs improved, the downside of slats made them unecessary and not worth the bother."
Ummm NOPE! (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
Just about every fighter plane flying today has slats, and so does just about every airliner. These days the slats are mechanically driven by an electrical or hydraulic actuator. On airliners they are linked to the flaps (same handle does flaps and slats). On fighters they are usually controlled automatically by the flight control system.
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Japanese fighters with butterfly flaps
Ki43
Ki44
Ki84
Also I think the N1K1-J and N1K2-J had automatic versions of these flaps. I am certain they were automatic but not so much they were butterfly flaps.
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Sink,
Are you sure? I thought all the Japanesse planes used the simple flap like the P-51 or the split flap design like the P-40.
Sharky
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Anal-retentive correction: Jetliners do not use Fowler flaps, they use Slotted (sometimes Double or Triple Slotted)Flaps, where the air can flow over and through the wing's trailing edge to maintain a smooth (laminar) flow. Fowler flaps do not have a gap between the flap and the wing. P-38s had Fowler flaps, a modern example is the Dash-8 Turbo-prop. (A fine Canadian product (http://bbs.hitechcreations.com/smf/Smileys/default/wink.gif))
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Cheers!
jocko-
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Automatic slats were very much used. I visited the airplane museum near Prague a month ago, and manually extended the slats of a La-8 ? or 7 ? I dont remember. There where no springs. Basically the stagnation point changes so that it is pushed forward (or sucked forward) at high AOA.
Even the F-86 had automatic slats.
Bod
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Funked and others...
Remember after the F-86, leading edge slats kinda took a leave of absence until the F-16. Granted, some of the delta-winged fighters had drooped leading edges and the F-15 has a rather dramatically drooped leading edge shape to the wing, the leading edge slat disappeared from USAF fighters until the concept of the mission adaptable wing reappeared with the F-111. The F-16 and probably all future USAF fighters will use drooping leading edges, but not true leading edge slats. The EA-6 and some other naval fighters continued to use leading edge slats through those interim years, but that is primarily because of the very low speeds required for carrier landings.
I think that some F-4 phantom variants used leading edge extensions and slats, and there was one variant with a slat on the elevator that also used engine bleed air for boundary layer control (increasing pitch authority at all AOA's) but the whole-wing leading edge slat at least temporarily disappeared in favor of a single simpler wing design or a relatively simple leading edge drooping mechanism.
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eagl <squealing Pigs> BYA
Oink Oink To War!!!
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Hi there,
btw: There is a series of SOCATA MORANE sportplanes, very common here in Europe, that uses these slats. The slats have no spring or lever activation, they're "sucked" out at a specific AOA. Never flew it myself but often tried the mechanism in our hangar. The pilot makes shure slats are extended during preflight check.
If I knew how to post a picture... (http://bbs.hitechcreations.com/smf/Smileys/default/redface.gif)
Cheers
eazydweeb
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Eagl, F-15's don't count because they aren't fighter planes.
<g,d,r> (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
And I'm defining slats to be devices which vary the incidence of all or part of the leading edge of the wing. I'm including full-span or partial-span configurations.
Admittedly, there are no slats on F-101, F-102/106, F-104, F-105, F-14, F-5, Harrier, or F-117.
But F-100, F-4, A-7, A-10, F-111, F-16 and F-18 use slats.
Looking abroad, Mirage, Tornado, Mig-29, Su-17, Mig-23/27, Su-24, Su-25, and Su-27 all use slats.
And new fighters like the F-22, Rafale, Gripen, Eurofighter all have slats.
So I think my statement, "Just about every fighter plane flying today has slats" is pretty much true.
Anyways we need to have slats and flaps on new planes so that I have work to do! Also I think we need more weapon bay door and pitch trim systems!
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"a relatively simple leading edge drooping mechanism."
Doh I should RTFM. I'm calling those slats. (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif)
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Sharky,
The butterfly flap was a development of Nakajima Aircraft Co. and was designed during the development of the Ki44 to meet a requirement to decrease turn radius. A button on the stick extended the flap during combat and another push would retract it. It was so successful the butterfly flap was installed in the Ki43 which was in preproduction. All Nakajima fighters designed after the Ki44 incorporated the butterfly flap.
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To stay on the original (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif). I am a survivor of a stuck slat incedent, and believe me I bought my pilot a steak dinner that night after properly disposing of my Flight suit.
I flew EA-3B's in the Navy as an Aircrewman. The A-3 is the navy version of the Douglas B-66 Airforce bomber. It was a late 40s early 50s twin jet design. On the edge of the wings outboard of the engines they had 3 sets of slats (On CLEO Winged A-3s they had 1 more slat on the inboard of the engine)that were Free fall type. I.E. the combination of Airspeed and angle of attack would retract them and as you slowed down the speed / angle of attack was not enough to keep them in would allow the weight to over come and they would extend. On our Modern day passengers these slats extend electrically. These slats enhance the curvature of the wing (IE making the little air molocules run faster over the top of the wing to catch his buddies taking the short path under the wing thereby lowering the pressure exerted on the Upper part of the wing making the air LIFT the wing UP (the principle of lift in simple form)) There for slats INCREASE lift at that time you want to slow down to land (IE if you dint have slats and flaps to increase lift you would need to fly faster to land and thats a BAD thing) Any way below is what happens when one slat disobeys and doesnt drop for some reason.
Anyway as a 3rd seater(I sat behind the Pilot looking backwards)/plane Captain/Crewleader/EWOP (Many jobs huh) on preflight one of my duties was to Push up on the slat to ensure free travel(the pilot did this also but hadnt gotten to this side yet). On this day I had one that traveled but didnt feel right. I had my pilot check and he agreed. So we called a mech out who said it just needed Grease and he would fix. Well He Greased it up and it APPEARED (Operative word here) to roll ok.
Well long story short it wasnt. We went a flying around and on return the slats came out save one. Well .. guess what happend. HARD roll over. Why did it, well you take a wing that has 2 slats out (1 stuck) I doesnt create as much lift as the 3 on the other side, well that creates a really NASTY hard roll (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) ). I dont know what my pilot did but he righted it (somewhere past the 90 degree rotation) and then accelerated (I think that was taken care of by the Ensuing dive we went into (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif) ) to get slats in. We then did a couple of manuvers designed to UNSTICK the slats (if the condition continues you have 1 choice BAIL because they are mechanical remember and if one sticks bad you cannot slow without losing control of the aircraft, the airlerons are not enough to correct it) Anyway this one finaly POPPED enough to drop with its friends. Found out later it was A roller bearing going bad on one of the slat tracks.
Poopy pant making day that was.
SO did that help with what slats do (http://bbs.hitechcreations.com/smf/Smileys/default/smile.gif).
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Rick "Firefox" Scott
VMF-214 / MAG 11
WB ID: firefx
AH ID: FirefxAT
Have Gun Will Travel
[This message has been edited by Firefox (edited 10-12-1999).]
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Wow Rick! Not a whole lot of people survive an assymetric slat extend. Usually it happens in such a bad spot (low & slow) that it's all over PDQ. Did you ingest a seat cushion during that adventure?
I can assure you we do a hell of a lot of stuff to make sure they don't do bad things like that! Of course our stuff is hydr. or elec. operated which solves half the problem, but there are still quite a few items on the failure tree that can get you in trouble. When I fly commercial I wish I had one of those M.I.B. memory eraser deals so I could forget all the bad stuff that might happen!
<S>
funked