Do delta wings typically not have flaps?

Sunny9850 said:
I am puzzled now myself, after watching the nice Ytube video of the 50th anniversary celebration of the JG74 where none of the Typhoon deployed anything. Slat or flaps...but of course they were air show light and showing off. With these modern birds the pilot makes a control input and the aircraft configures itself to make it happen. So the slats and flaps may just not have been needed.

Or I could be mistaken on the existence of flaps...could it have been the Saab Viggen that had them ??

Anyway...here is the video.
http://www.youtube.com/watch?v=Um9XH4GnC00&feature=youtube_gdata_player

Cheers
Stefan
Click to expand...


No, Stefan, I think you are right; and right on all counts. Typhoon does have "flaperons" but probably doesn't use them much in airshow/light config (which would include Matt's Coningsby landings) as the onboard systems will make needed adjustments to maintain stability & controlability. I'd still be interested to hear what Matt's "contact" has to say on the matter, but that kinda makes sense to me.
 
"Pitch control is provided by symmetric operation of foreplanes and wing flaperons, while roll control is primarily achieved through differential operation of wing flaperons. Yaw control is primarily provided by the fin mounted rudder. Cross feeds among the various actuation systems are also implemented to optimise aircraft performance and handling qualities. The slats and flaperons automatically optimise the wing camber at all Angles of Attack (AOA)." - Eurofighter.com

have left a message with my buddy, will report back when i hear anything... :salute:​
 
Flaperons to control the camber of the wing....that is the traditional sense. As I said earlier the idea is to create a "thicker wing" which generates more lift at a lower airspeed combined with an increase in drag to allow a steeper descent without increasing the aircrafts speed.

It really doesn't get any more traditional than that. Some flaps do a better job of one aspect or another but in the end that is what all of them aim to do.
Simple hinged flaps may do more in the drag area than in the addition of lift and highly complex fowler flaps, such as what you find on a 747 create huge amounts of additional lift by radically changing the camber or aerodynamic profile of the wing.

The text from Eurofighter.com also points out that the flaperons, along with the slats, perform this function automatically as I had suspected. The pilot simply moves the flight controls where he wants the airplane to point and the throttle to give him the speed he desires...the airframe and computers simply make that happen...as far as possible.

Cheers
Stefan
 
the most i've seen in travel is a few inches but never more...

View attachment 64734
^Fully Up, neutral control surfaces....

View attachment 64738
^'Standard' landing, maybe 3 inches of travel....

what i'm thinking he means is that the droop on the trailing edge, being computer driven, changes the overall shape of the wing, kinda like how flaps travel down and back to increase lift area in conjunction with the slats... as opposed to the general droop of the surfaces in totality... if that kinda makes sense....
 
In the first shot the slats are obviously down, likely because the pilot commanded a high AoA bank. The second one already shows the aircraft very much nose high, resulting in a high AoA.
If in the split second the picture is taken the pilot pulls back a bit more on the stick there simply is no downward deflected "flap" left as the trailing edge surfaces now act in their elevator mode. Combined of course with the canards on the nose.

Do they ever act like traditional pilot controlled downward deployed surfaces. Not likely...because they are not simply flaps. They combine three control surface functions in one.

Take a look at the flaperons on the Mu-2 or if you like it simple the Kitfox. In both cases the control surface does double duty. And again the downward deflection is condition upon the pilot input. A roll command will change how much "deflection" there is.


Stefan
 
Basic tailless deltas, before the advent of ccv, don't have flaps because, as noted earlier, there isn't a way to cancel the pitching moment that would be caused by them and delta wings also produce much higher lift than a standard wing due to the vortex off of the apex. Of course, that vortex bleeds a lot of energy (drag) and that is also why the delta requires high power settings as well in the landing configuration.

Granted it lands faster than a conventional jet, but one of the reasons/advantages of the delta is very low maintenance, since you don't have a complex flap system to maintain. This also lowers their weight and cost of construction.

Also, as noted in one of the books on the CF-105, Deltas are more sensitive during take-off and approach and it is much more important to have the correct alpha and not "hunt" for it in pitch due to the fact that, for an instant, as you pull up to get higher alpha, the action of the deflection of the elevons causes the plane to lose lift, due to reduced camber (Or air hitting the up deflection of the elevon if you prefer a Newtonian reference). So at first it loses lift as you rotate up, then it gains lift as it stabilizes at the new alpha. I also suppose the corollary would be true for a nose down pitching moment. I should note, this seemed to only be a nuance at the lower airspeeds in the patterns. I would guess that would be due to the higher deflections required at the lower speeds (low q), since at higher speeds much smaller deflections would be necessary.
 
Personally my two favorite deltas were both from the USAF Century series of fighters. Both were built by Convair, and both kicked ass in the air defense role. I give you a gentleman's fighter.

The Convair F-102A Delta Dagger and the F-106A Delta Dart. Both have flaps....
 
With all due respect to Mr. Ito, I don't think either of those aircraft had flaps in real life.

On my AlphaSim F-106 model the inner surfaces act like elevators and the outer ones are ailerons. No flaps.
 
Cowboy1968 said:
Personally my two favorite deltas were both from the USAF Century series of fighters. Both were built by Convair, and both kicked ass in the air defense role. I give you a gentleman's fighter.

The Convair F-102A Delta Dagger and the F-106A Delta Dart. Both have flaps....
Click to expand...

I was referring to the real aircraft which have elevons, not flaps. The FS airplanes incorrectly have flaps. ;)
 
I stand corrected, looking through my books, I can't find evidence of flaps on the 102 and 106....

Thanks for the reason to dust off some old covers....
 
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