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Drooping FireFly Flaperons
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bill_joe(at)bellsouth.net
Guest

Posted: Mon Jul 21, 2008 5:04 pm Post subject: Drooping FireFly Flaperons

Hey Guys



    I think the person you are talking about is Izek,I think at one time he 

did fly with some kind of weight or sand bag when he flew alone . It belive 

I remember at the S&F that thing got loose and did some damage to the nose 

on the way down there in the trailer.That was a long time ago when Brian 

Blackwell or Blackwood was a part owner. I hope I have this correct..



                 Bill Futrell

---

jbhart(at)onlyinternet.ne
Guest

Posted: Mon Jul 21, 2008 5:22 pm Post subject: Drooping FireFly Flaperons

At 08:15 AM 7/21/08 -0500, you wrote:

 	  Quote: 	
		  

I believe Jack H mentioned he drooped his flaperons about a degree.  I doubt 

that amount is even measureable in flight.  




	


John H.



See how I measure it at:



http://www.thirdshift.com/jack/firefly/firefly116.html



I can measure elevator position by:



http://www.thirdshift.com/jack/firefly/firefly102.html



and I have an ASI and a VSI



So I don't have to judge by feel alone.



Jack B. Hart FF004

Wionchester, IN

Steven Green

Joined: 05 Feb 2006
Posts: 118

Posted: Mon Jul 21, 2008 5:27 pm Post subject: Drooping FireFly Flaperons

Here is a pretty nice article I ran across when I did a search on "flaps, 

center of pressure"



http://www.bcchapel.org/pages/0003/pg3.htm



Steven Green

MK3 912S

550 hrs

10EC

_________________
Steven Green

gaman(at)att.net
Guest

Posted: Mon Jul 21, 2008 5:51 pm Post subject: Drooping FireFly Flaperons

Sorry Thom,

I missed something here If in trimmed level flight, flap is added,the angle of attack in my Kolb decreases.Does the center of lift move back with the addition of flap?



---

pj.ladd(at)btinternet.com
Guest

Posted: Tue Jul 22, 2008 7:41 am Post subject: Drooping FireFly Flaperons

There are other ways to trim a Kolb rather than add additional weight.>>



Hi John,

lowering elevators etc will no doubt get the job done but it doesn`t change 

the W&B calc, and that is the problem surely



Pat (seeking enlightenment)

NeilsenRM(at)comcast.net
Guest

Posted: Tue Jul 22, 2008 8:44 am Post subject: Drooping FireFly Flaperons

I moved my battery to the nose cone. This moved the calculated CG to right 

where it is supposed to be.  I was later told by Dennis Souder (the previous 

owner of Kolb after Homer) that the CG calculations were set to keep the FAA 

happy but CG figures a bit aft of the limit fly just fine.



I for one would approach aft CG limits very carefully.



Rick Neilsen

Redrive VW powered MKIIIC



---

by0ung(at)brigham.net
Guest

Posted: Tue Jul 22, 2008 6:58 pm Post subject: Drooping FireFly Flaperons

No, drooping should not increase the angle of attack, it should reduce it.  Drooping the flaps changes the overall shape of the airfoil giving it more lift, and more lift at any given speed should require less angle of attack to remain in level flight.  And by drooping the flaps, the center of lift for the wing should move to the rear.  With the center of lift more aft it should require more down pressure on the tail to remain in level flight.  

   

Don’t confuse increased lift with more angle of attack.  And by increased lift, am referring to increasing lift due to the change of airfoil shape.  

   

  However I can think of one reason that could explain the results that seem to go against the grain....     

If the slight deflection of the flaps causes the airflow  going across the wing to descend causing it to strike the top of the horizontals  and elevator,  it could increase the air pressure at that point. Giving results that seem opposite from what you would expect.   If this is the case and further testing is warranted.  It could cause an upset in attitude with changes in airspeed as the deflection angle of the air changes.  This could become potentially dangerous if the plane has to have massive stick pressure changes with speed changes.  

   

Try an experiment and reflex the flaps and see if the back pressure is reduced.   It might tell you more about your situation.  

   

Boyd Young  

Kolb mkIIIC    

912ul 530 + hours and counting.  

Private pilot since 1979  

   

 	  Quote: 	
		  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>   

Drooping the flaperons (or flaps) a bit increases the angle of attack a bit. The increased angle of attack results in a little more lift. The increased lift would result in a slight climb and loss of airspeed unless the pilot retrims, or in Jack's case, relaxes the back pressure. Relaxing the back pressure restores the angle of attack to its pre-droop state with a resulting slight nose down pitch. Thus the stabilized state is restored with less up elevator pressure.   
	


   

       [quote][b]

pj.ladd(at)btinternet.com
Guest

Posted: Wed Jul 23, 2008 2:12 am Post subject: Drooping FireFly Flaperons

I for one would approach aft CG limits very carefully.>>



Hi,

I am with you on that, all the way. Aft Cof G is apt to be a killer, 

literally.



Cheers



Pat

gaman(at)att.net
Guest

Posted: Wed Jul 23, 2008 4:01 am Post subject: Drooping FireFly Flaperons

One last note on the w&b thing.I raised the leading edge of the horizontal stabilizer 1 1/4" on my firestar and spring loaded the elevator favoring nose down with an adjustable trim .It could be flown hands off  IN CALM AIR.But it was like crossing a boats wake, only longitude wise, with a quick pitch up then back to level, in rough air,and during a maximum effort slip,putting the stick up in the corner with opposite rudder,when the elevator lost effectiveness it would pitch up dramatically.I'll never forget the first time THAT happened.I added some nose weight to bring it into mid-range cg and it became a much more comfortable aircraft .My MK-3 is similarly afflicted.I'll carry the  weight.

                                                                G Aman MK-3C Jabiru 2200 350 hrs 

---

jimhefner

Joined: 11 Jan 2006
Posts: 91
Location: Tucson, AZ

Posted: Mon Jul 28, 2008 7:55 am Post subject: Re: Drooping FireFly Flaperons

Hi gang,



I happened to visit the Kolb list this morning to see what's happening and saw this discussion, which brought back memories of how much I liked the continuously adjustable elevator trim tab on my old Firefly.  It was mounted on the rear edge of the left horizontal stab and worked beautifully.  No matter what rpm setting I chose, I could trim it out for level flight in a split second and not have any stick pressure to tire me.  No other tweeks of flaperons or angle of incidence to mess with.... I highly recommend it!  



Each time I flew to Copperstate, the elevator trim tab and VG's were the main discussion points of folks stopping by.... several folks lifted the tail to take photos of the trim tab setup.  It was on the Firefly when I bought it so I don't know the details of the parts used or where they came from, but I was sure glad the previous owner had installed it.  The actuator was a friction lever that held the setting wherever you wanted it.  It pulled against a spring that held the trim tab in position against the pull of the cable.   If anyone is interested in more info, contact Henry Voris.  I'm sure Henry wouldn't mind taking a few photos to share here.



Take care!

_________________
Jim Hefner
Tucson, AZ
Do Not Archive

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