spaceworm

Are we talking about Opel Kadetts?




With apologies to ath5774.

Sincerely, Richard

FlyerInOKC

My Feedback: (6)

Nope, wing too short!

nealmontgomery

SLOTTED FLAP MOD - SIG KADET SENIOR
A well-designed flap system can allow a nice, slow, precisely controlled approach leading to the execution of a well-timed flare and landing. Pilots appreciate a perfect approach and landing. It implies confidence and competence. It is possible to get a perfect landing (and an approving nod, or even applause for your effort) more often than not. Instant credibility! Slower landings are certainly easier on your airframe and gear. You’ve seen guys bash their airplanes, tear off gear, snap roll into the dirt, or land long into harmful obstructions time and again with hot landings. On my SIG Senior Kadets (4 so far), I have installed flaps on them all. I have often had hover-down, no-roll landings when the wind was just right, again, to applause from the flight line. People get a big kick out of it. I love the flaps. If I buy an airplane without flaps, I modify it to put them on, yes, even ones that don’t need it, like the Sig Senior Kadet, my all-time favorite. All my other airplanes are flapped too.

I’ve been building and flying for many years. As an A&P, I have seen all kinds of flap configurations and flap track/linkage setups on small and large aircraft and I like to try to replicate them. Double- and triple-slotted flap systems , 4-bar linkages and inverted 4-bar get into the realm of the mystical insofar as R/C applications go. While the Fowler Flap is my admitted favorite, its linkage is more complex. It is difficult to get the true rearward travel aft before the downward translation. I have seen many modelers who claim their configurations emulate a true Fowler Flap deployment schedule, but a significant portion of them do not. Not a judgment, just an observation. Lately though, I have become more interested in slotted flaps. They are simpler, and nearly as effective. A slotted flap nests within a flap “cove” under a “lip” which extends past the upper wing surface aft spar and over the front portion of the flap when it is at 0 degrees deflection. As the flap translates backward and downward through its arc, a slot is created which accelerates the air through the slot, just as with a venturi, combines with the upper surface flow, improving airflow over the flap. It increases lift without the bigger drag penalty later in the deployment schedule. Their effectivity is in the region of the Fowler Flap, but without its complexity. It’s a great compromise and visually appealing when executed correctly.

I searched the NASA Technical Reports website and found one of many old reports (NACA TR 664) on slotted flap configurations. The reports are great resources for technical information, but more importantly, the report includes exact dimensions for the wing/slot/flap combination itself, the slot and lip contours, the mounting configuration, and where the flap needs to be relative to the wing trailing edge/slot when deployed. It matters a good bit where the flap is when it is deployed if you want the maximum benefit of lift vs. drag. Just throwing a flap “out there” does work, but not nearly as well as it could.

According to NACA TR 664, pg. 22, slotted flap configurations, 2h, illustrated in the report, gave the best overall performance and the specifications for that setup will be the basis for our mod. I know that all the Reynolds Number guys will be pointing out that what is in the report does not translate, but I’m going with it anyway.

I will share with you, dear SIG Brothers and readers, what I did and how I did it.

Ready?\

nealmontgomery

For those who wish to follow along, here is a link to Technical Report 664

http://naca.central.cranfield.ac.uk/...report-664.pdf

box car

mike, put them on your ignore list

Muttdog

I have half built Kadet senior. The fuse is 95% done and covered in white monokote. Wing is about 50% done but Ailerons were not done. I'll have to pull the box out to see the rest as it's been a while. If anyone that lives near S FL is interested in it PM me. I can get it to top gun for a tank of gas or the Pro Bro event in Ormond beach March 15. I can ship greyhound but the costs may be prohibitive. Hate to see it collecting dust and I'm into 3D aircraft now so it won't go any further in my hangar.

spaceworm

Hi Muttdog, what are you asking for it, picked up in Jupiter?

Sincerely, Richard
Kadet Brotherhood #96; Mk 1 Kadet, Kadet Junior,
Sig Kougar, Sig 1/4 Cub, Sig 1/4 Spacewalker II

Thanks

FlyerInOKC

My Feedback: (6)

Neal, thanks for the primer on flaps! Very interesting reading, would you have any pictures of your airplanes with the Fairey-Youngman flap installed?

Mike

skylark-flier

Comparing my original 1973 bird alongside my Mk-II;
1. vertical stab/rudder changed from straight up & down with rounded top to swept with flat top
2. original has clear windshield, vs Mk-II solid balsa
3. original has heavy wire main landing gear vs Mk-II aluminum strut
4. original has carved balsa block wingtips vs Mk-II built-up (cub-style)

That's really all I see.

FlyerInOKC

My Feedback: (6)

Thanks Dave! Can I get a picture of the tail or are the pictures of a modified tail posted look the same?

Mike

flyingagin

Neal I am at some point in the future going to make a new wing for my SR. I am planning on slotted flaps. Already made the templates to stack cut the ribs with. Also going for a low wing with plug in wing panels. Just have to add the carry structure at the bottom of the fuse. Nothing down there in the way now. Plus add a new cover for where the normal high wing sits.

Ken

Muttdog

To be honest I am not really sure as I haven't seen the complete plane in a while and on top of that I'm not really sure what a partial built kit is worth. If your close to Jupiter, I can bring it to my office tomorrow or to Dyer Field Saturday morning when I fly and you can tell me what it's worth to you. My plan was to bring it to that swap meet in Delray next month but I already sold just about everything else I was going to bring there. If you want to try and meet up PM me with your phone # or Email. If it's a drive for you, I'll pull it all out tonight and snap some pics.

nealmontgomery

Mike in OKC,
I have not fabbed any Youngman flaps, but there is a great little video on YouTube which demonstrates them quite well. I was including that type of flap as an illustration of my addiction.

http://www.youtube.com/watch?v=AqXEQ5LA_eg

I wonder what the NASA archive has on Youngman flaps? I will search. If you find something before I do, please share.

Thanks for your interest. Will continue the thread soon.

nealmontgomery

The flaps on my FMS T-28 were originally hinged at the lower surface. The gap presented when the flaps deployed was visually unappealing and functionally counter-intuitive to me and I thought a slotted flap project would be just the thing. I consulted NACA Technical Report 664 and set to work.


Aren't these awesome? I have about 65 degrees maximum deflection or anywhere in between. About 10 degrees for takeoff, base, and crosswind segments and go to full flap as needed for Final. Slows down beautifully.

You can see the slot begin to appear from even a small deflection angle. IAW TR 644, the slot is sealed at 0 degrees and begins to manifest itself right away.

When I can figure out how to shrink the file size, I will post a video of landing on the Functional Test Flight (FCF). Super easy and quite slow.

This is a heavy airplane, so I was quite pleased with the result.

Sorry for putting a T-28 in a Senior Kadet forum. Just presenting a precursor to what the big Sig's flaps will look like

acdii

See, we kept the thread alive long enough for some real Kadet talk! Always a madness to our methods!


BTW, If anyone wants to compare kit prices from 1997, I have a nice catalog from that year.

nealmontgomery

Flyin'....
would refer to the TR and make sure that you have enough room to fabricate your lower surface Slot Transition leading into the slot. If you have a sub-spar to attach it to, great, if not, you will need to fabricate your own sub aft-spar to ensure you have structural elements to create a strong transition attachment.

Dang, it would ahve been a blast to be at Langley back in the day to research all this stuff.......a modelers dream world, I bet.

Also.....templates are indispensable for creating the very precise contours dictated in the Technical Report, which will ensure you have the correct geometries down the road.

BigTeeEldorado

Nice work Guys! I leave for a while and come back to learn about flying cars over the top of a hill...... so off topic? yes.... but at least about flying and you kept the thread pretty lively.

About the rudder and stab aesthetic mods, I really like that new look and agree a simple change can go a long way. I know I'm going to use it

About the flaps, keep the info and especially pictures coming cause I can't comprehend without pictures and I am very interested. There are many possible applications and just FYI to Nealmontgomery if you check out some of my early posts to this thread you might find a Kadet with Junkers style that gave me some awesome STOL characteristics.

I am busy but I've got my eye on you guys so................

flyingagin

Like that is gonna stop us from getting into trouble

Ken

BigTeeEldorado

Ya it didn't work for my parents either!!

flyingagin

I am a bad boy. I done got us off subject again

Ken

skylark-flier

Hey Mike, these are pics of the original 1973 Kadet - direct from SIG. I have them in my library as the Kadet Mk-I but they're actually the original 1973 Kadet.

box car

I am doing a kadet STOL at this time, using the CH701 as my copy

Larry882

It's 2AM here in Georgia and I have been sleeping in the recliner since American Idol ended. I decide that this would be a good time to
put the wings on my Kadet and take some progress pictures. I'm pretty happy with the project so far and haven't run into any serious
problems. I still need to build the Rudder and cut out the ailerons.

Larry882

I must not be doing this right because the Text is lined up right when I add the pictures but gets unaligned when I post them. Any Ideas what I'm doing wrong?
Larry

skyrat71

Larry, your pictures are added where ever the little cursor bar is when you upload them to your post. Try hitting the enter key and starting a new line under your text before attaching photos. I refuse to admit how long it took for me to figure that out.