Stabilator - designs

[Chuck Fabo]

After reading discussion threads on sealing stab-elevator hinge-lines, can anyone suggest  a few designs that incorporated a Stabilator?  Thanks.

[Dave_Trible]

After reading discussion threads on sealing stab-elevator hinge-lines, can anyone suggest  a few designs that incorporated a Stabilator?  Thanks.

The stabilator is something used most exclusively on combat airplanes.   It has never really been used for stunt with one or two exceptions I can think of decades ago.   It probably could be used with development in stunt but a lot of the technical troubles will be around the hingeing of the unit to be loose enough to work effortlessly yet be solid enough to prevent flutter.   That bearing assembly could be heavy in a bad place on the airplane.  Of course you could do it with twin booms but that's another subject...A significant bag of worms with no real advantages.

Dave

[Brett Buck]

After reading discussion threads on sealing stab-elevator hinge-lines, can anyone suggest  a few designs that incorporated a Stabilator?  Thanks.

     I haven't seen one that was designed that way from the start. The few I have seen are retrofit to existing designs. There have been a few lengthy discussions about stabilators/flying stabs on stunt planes, I would suggest you check those out, because I don't think there is a lot more we know about it.

       Brett

[Ken Culbertson]

I have built two back in the 70's.  They flew fine.  You need a wide fuselage.  Mine were Jet type patterned after the F-14.  The pivot was at 25% which pretty much eliminated flutter.  It was mounted using "tube inside tube" for the mount and a fiberglass arrow shaft for the backbone.  Today I would make it thicker from CF and use light ball bearings like I do with my Canards.  The zero slop from ball links make it very viable.  If my Canard twin is successful, and so far it is, the next one will have a stabilator.  Contrary to popular myth, they do not hunt any more or less than stab/elevator if the pivot is right.

Ken

I remember a twin boom design using one around the time I did mine.  I think it was published. Does "Pegasus" ring any bells?  Maybe not.

[Dan McEntee]

I have built two back in the 70's.  They flew fine.  You need a wide fuselage.  Mine were Jet type patterned after the F-14.  The pivot was at 25% which pretty much eliminated flutter.  It was mounted using "tube inside tube" for the mount and a fiberglass arrow shaft for the backbone.  Today I would make it thicker from CF and use light ball bearings like I do with my Canards.  The zero slop from ball links make it very viable.  If my Canard twin is successful, and so far it is, the next one will have a stabilator.  Contrary to popular myth, they do not hunt any more or less than stab/elevator if the pivot is right.

Ken

I remember a twin boom design using one around the time I did mine.  I think it was published. Does "Pegasus" ring any bells?  Maybe not.

   Jean Pailet published several stunt models back in the 60's and one was the Pegasus and it was a twin boom with the stabilator.  The story I heard was that is was so bad that he pulled the wing out of it and used it in another published model called "The Zephyr". It actually looks pretty nice, So did the Pegasus. Put the Zephyr stab/elevator in the Pegasus twin booms and you might have something!!  The stabilator comes around in discussion about every 5 years or so!!
   There was another Pegaus by Bob Howard that is a nice looking airplane also, but conventional in set up and planform.
  Type at you later,
  Dan McEntee

[Steve Thompson]

Here is a Stabilator design.

I found it in an old model magazine and ran across it again just a few days ago.

I put this pic in Stunt Hangar a few years ago and Paul commented with his opinion on stabilators.  Not for me to recap, but if you search, you will find.

He has had quite a career in stunt since then!

[Steve Thompson]

Follow up:

I had bad hair that looked like that back in that era. 

But Paul is a classy guy, so I think it is not hair, but rather the trees in the background.

THAT is my question about the stabilator picture...

[Steve Helmick]

When Paul Walker was still living just a half dozen miles away, I stumbled upon that picture and asked him about how the stabilator worked out. I don't remember exactly what he said about it...but it wasn't good!  Steve

[Ty Marcucci]

I think an I beamer called "Nuts -N-Bolts" had one as well..

[M Spencer]

They work better than Elevators , supersonic . 

Bloke in Kiwi Land had one centuries ago . Alan Laurance ?

SEEING you brought this up , and SEEIMNG I was looking at THIS , yesterday .

Youll SEE it has a ' flying tailplane ' ( as it were ) but It was Wheel Operated .
Maybe a scrool type postive action ( worm & wheel ? ) set up might be the
bees knees , for positive tracking , onem . ??

Whatever . the ' dead zone ' of a plank tailplane blanketing minor eveator travel ,
isnt there . Differance from 5 m.m. at T.E. , to Zero , was 3/4 inch in the C. G. ,
Fwd. required with zero slack , so it wouldnt weave . Everywhere .
Soon put the slack back in . After a few weeks . So wasnt as if it wasnt tested every day or two . Like it . No .

So , the AIRFOIL on the flying tail , and the hinge / aerodyamic balance - position is a THING .
a flat 1/4 sheet with rounded leading edge , cut trimmed & butchered , at the field ,
on a already a bit used heap , might be a good ' try out ' . And get you somewhere .

A C.F. tube spar , through hardened fuse bearers / pivots . So YOU DONT get stab flex messing up things . might be required .



FIN on this too , is ' full flying ' ( B.A.C. TSR II ) . Givera whirl . Fair crack off the whip .

[frank williams]

Bill Wilson of the Dallas area has built several that fly well.

[Ken Culbertson]

Bill Wilson of the Dallas area has built several that fly well.

I like what he did with the mount.  You need the width. It looks like the pivot is around 25%

Ken

[M Spencer]

Heres a load of something vaguely relevant .

https://ebrary.net/59631/engineering/complete_spar_boom_model

Id consider ' hard plates ' , C.F. reinforcing , sheet ply load spreaders or sumsuch , in the sides back there .

Let in brass gromets or suchlike , for a revolving spar . ( The Simplist perhaps )  OR

a Fixed Spar , 1/2 span . The ' tailplanes ' revolve on . ( likely the least deformable ) maybe tube as structure  of surface - over tube load bearing fixed spar  .
with a lucky box r two in there somehow . depends if its a ' come apart ' .
Ah Ha .



If you had a cradle / saddle ( for a round spar ) like a 4 bolt main cap . ( with a slot for a horn ) you could out & in it . Shim it & lube it . too .

Tho with the cross cap , one piece . Slotted . as integral , structure . small piece of aluminium channel , perhaps . perforated for lightness & drilled and tapped for securing things . 


but more in this vernacular ;



As in a RIDGID load bearing ' skeleton ' framework , SPAR -to - distribute into rear bay / bulkhead . the working loads . accuretely & securely located . Bit a a mission , but a trifle scientific .


in principal , like the framework , if not in fact . So a whittled Alumn. ' U ' ( in plan or X section ) hacked away skelatel , wiith SADDLES FOR A SPAR , would getta bitta location going back there ,

[pmackenzie]

I think an I beamer called "Nuts -N-Bolts" had one as well..

A buddy in Michigan made a replica "Bolts" a couple of years ago, right down to matching the original paint scheme.
The original had the stabilator pivot point at 50% of the chord, he moved it to about 25%.

Fox 59 for power.

[Robert Zambelli]

I may have posted this before but it might be of interest on this new topic.
Around 25 years ago, I built a semi-scale stunt model of my PA-28-151 Cherokee Warrior.
The model would have as many features of the full-scale plane as possible including a dihedral wing with multiple taper, wing root cuffs, R/C throttle control, functioning marker lights, wheel brakes and a full-flying tail (stabilator).
The tail was to pivot on a ¼ inch carbon fiber rod turning in two precision sealed ball bearings. The bearings were mounted in a rolled fiberglass tube attached to the airframe.
Going with a suggestion from Bill Netzeband, I set the pivot point 25% back from the stabilator lead edge.
The plane flew quite well, turned like a combat plane but was too sensitive. Closing the handle spacing to 2 ½ inches lessened the sensitivity issue somewhat.
HOWEVER, on the occasional instance when the lines became slack, the plane went into a rather wild pitch oscillation, fortunately always correcting itself.
I surmised that the problem might be due to the pivot location so I spoke with Bill. He suggested that I reduce the distance from lead edge to pivot to around 19%. So, I reduced it to around 18.75%.
After the modification, the plane became much less sensitive and the oscillation was gone.
Although I won a few trophies in Fun Scale, I really built the plane just for fun. Powered by a SAITO 30, I can throttle it back to idle, do a touch-and-go or use the brakes for a full stop landing.
After approximately 1,100 flights, the engine has never been out of the plane, the valves were adjusted once, (after break-in) and the glow plug has never been changed. 1 1/2 ounces of fuel is sufficient for the pattern.
 JUST PLAIN FUN!!!!!
Bob Z.

[Gerald Arana]

I may have posted this before but it might be of interest on this new topic.
Around 25 years ago, I built a semi-scale stunt model of my PA-28-151 Cherokee Warrior.
The model would have as many features of the full-scale plane as possible including a dihedral wing with multiple taper, wing root cuffs, R/C throttle control, functioning marker lights, wheel brakes and a full-flying tail (stabilator).
The tail was to pivot on a ¼ inch carbon fiber rod turning in two precision sealed ball bearings. The bearings were mounted in a rolled fiberglass tube attached to the airframe.
Going with a suggestion from Bill Netzeband, I set the pivot point 25% back from the stabilator lead edge.
The plane flew quite well, turned like a combat plane but was too sensitive. Closing the handle spacing to 2 ½ inches lessened the sensitivity issue somewhat.
HOWEVER, on the occasional instance when the lines became slack, the plane went into a rather wild pitch oscillation, fortunately always correcting itself.
I surmised that the problem might be due to the pivot location so I spoke with Bill. He suggested that I reduce the distance from lead edge to pivot to around 19%. So, I reduced it to around 18.75%.
After the modification, the plane became much less sensitive and the oscillation was gone.
Although I won a few trophies in Fun Scale, I really built the plane just for fun. Powered by a SAITO 30, I can throttle it back to idle, do a touch-and-go or use the brakes for a full stop landing.
After approximately 1,100 flights, the engine has never been out of the plane, the valves were adjusted once, (after break-in) and the glow plug has never been changed. 1 1/2 ounces of fuel is sufficient for the pattern.
 JUST PLAIN FUN!!!!!
Bob Z.

Hi Bob, Another thing you could've done was to balance the stab. I would've put a full length LE wire (maybe 3/32" dia.) or maybe bigger/smaller to static balance the stab. (ilator)

On the "Nuts and Bolts" the pivot point is WAAAYY to far aft. Moving it to 20-25 % and balancing it would probably make it fly a whole lot better.

All my competition gliders have stabilators (had!)

Cheers, Jerry

[Ken Culbertson]

The tail was to pivot on a ¼ inch carbon fiber rod turning in two precision sealed ball bearings.

That is exactly how I mount my Canard.  I plan to use it for the stabilator on the next one.  25% is a good starting point.  Interesting, I had noticed a similar phenomenon on sharp upturns with "slack" lines that was also self correcting on my first canard.  I replaced it three times finally settelig on one with a higher aspect ratio and a pivot around 15% AMC.

Ken

[Paul Taylor]

Bob’s plane is in this video.  Scrub to around 42:45. https://youtu.be/ohYLNssJ76A?feature=shared