A Tangent .

[Air Ministry .]

Though for some time , why not a Bi Plane with flat inner surface Wings , for STUNT .

As in



More or less . ( Clarke ' Y ' .) Reversed to FLAT TOP for the lower wing . ( inverted airfoil .)

Would think a bit of convergance or divergance on the inner face alignment might help .

one of these , went whistling round inverted for a lap relitively effortlessly , in a ' bit of a blow ' at a field in a saddle in a hill .( its got FLAT UNDERSIDE WINGS ) .
OS 10 in a F Flight converted to C / L . ( had won F. F. Jnr. Scale at the Nats . If it'd been COMBINED F F & CL Jnr Scale , there wouldve been TWO entrants !    No More ! )


Cut almost upwind . say 15 knot . Hit the deck & it scooted tail up a half lap from top of circle to our boxes . A little more sheltered there . A ' Wheeler ' till stopped ! . RIGHT .


So since then , this we've wondered . !

But NOW , some silly sod has created an imaginary winged thing ( likely plastic or computor art . )



Excuse the Canard .          RIGHT , a very small gapped parrallel flat inner sectioned Bi Plane WING . !

SLOTTED , Even ! ?

Now we can get nasty .

And put the FLAPS in the FLOW between the Two Wings ! This'd approximate to ' blown ' flaps or control surfaces , full size .

Prevents the airflow breakaway under duress .

https://www.beyonddiscovery.org/aerodynamics-2/842-control-by-tangential-blowing.html

So . Next year everyone can do five foot square corners !       

Well , would provide a unique design concept perhaps . Conventional plan fom even .
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So we make it not so imaginary by turning it into a half or 3/4 or 1 in gap .



But we keep the FLAP hinged about the centerpoint of the gap between the trailing edges , so its in a somewhat unobstructed aiflow . Or ducted airflow .



Where it says " center of pressure " the top & bottom are prised apart say  5 or 10 % of the chord. dimensional . Between the inner flat faces . creating a flow through & effectivly symetric action ! .

[Dave Hull]

Crikey, AirMin!

Biplanes have excess drag due to the interference of flow ahead of and between the wings. The heavier the wing loading, the worse the penalty. The farther apart they are, the less the penalty. Put them really close together and you get a "howler:" the airflow howls, but not so loud that you don't hear the howls of laughter from the engineers from the competing companies....

What you'd like is for both wings to work hard at the same time--but not against each other. Unless we're building a novelty plane here. Those are fun as long as they don't cost you anything in either time or the King's coin.

As far as your suspended flaps, go take a look at the earliest generation of "boxkite styled" airplanes. The Curtis had ailerons suspended between the wings, if I recall correctly. Seemed better than wing-warping, so I'll meet you halfway on your advice--I'll try to keep the wing on each of my control line planes from warping.

But your graphic is priceless: the nose of an F-106, the tail of a McFarland Shark 45, the wing accoutrements of extreme Rutanesk application, and a belly bulge that would make any Gulfstream jet jealous....  Brilliant! And perhaps it takes all of that to justify the roundels?

The Divot

[Air Ministry .]

AH , but its NOT a biplane . It's a SLOTTED WING ! 

Asin , split a Std wing , fore & aft .

As for DRAG , it'd keep the speed down . And theres a chane a ' 90 ' might have enough grunt .

IF one had a foam cutter , wouldnt take much more than an evening to get a stick type test ship thrown together ,
no finish reqd. if electric .

Airflow top & bottom of the flap , should mean its wunderkind , near unstallable . The low speed'd help the tight turn .
However , theres a chance it might not work . Whatever ,

Cant  say who did the illustration . tripped over it on the net. used as it almost shows a ' slotted wing ' .



You could even put an electric heater in it , and use it as the powerplant . 



They actually used these ( radiator / intake ) as it was less drag . But the
bureaucracy was worried about bullet holes in them , and ordered them put elsewhere .

Mosquito , Hornet , Tempest One , Sabre Fury , used that intake . So if one was devious , a plenum and bleed to ' blow ' the flaps , would get them working in extremus .

[Brett Buck]

Mosquito , Hornet , Tempest One , Sabre Fury , used that intake . So if one was devious , a plenum and bleed to ' blow ' the flaps , would get them working in extremus .

    The radiator was to harness the Meredith effect. It recovers some drag that would be lost otherwise, and as long as you have to cool the engine somehow, might as well use the heat for something useful.

  Doing something similar minus the heat source, and all it is is drag.

   Note that the same thermodynamics apply to things like nuclear jet engines, where all you have is heat - suck it in, compress it, heat it up, then allow it to expand.

     Brett

[phil c]

When I think bipe stunters I think of Pete Simonson's Gypsy Moth(I think, it's been awhile.  It had symmetrical airfoils and, I believe, an Enya 45.  The plane seemed to fly very well, although I imagine Pete would run into some trouble if it was windy.  Rather than making it a "caricature" plane he built it with very few modifications and almost all rigging.

The flat bottom wings are counter intuitive.  I'd have to build a slap-it-together test plane first.  Just from standard aeronautics it's most likely that the flat bottoms would stall and simply add drag and turbulence.
I'd start with symmetrical wings both high and low.  We know those should work OK.  The airfoils can probably be built with an averagely thick wing->12%, <18%.

Send a picture when you get your version flying.

Phil C

[Dan McEntee]

  Who doesn't like biplanes!! I had a SIG SPAD as a kid and want to build another just because, along with the Fokker D-7.  I have seen several Brodak .38 Specials fly and they fly quite well, it seems to me, and have one of those in my stack. Using some of the design theories and numbers from that design and apply that knowledge to the SIG models to hopefully help their flight characteristics. I have wondered if you were sweep the wings of the .38 Special and change outlines to make it look like the Tiger Moth. or sweep just the top wing and make it look like  Pitts Special. Lots of possibilities, not to make them world beaters, just fly as best as possible and have some fun and turn some heads. Bevo Howard's Bucker Jungmeister comes to mind also.
  Type at you later,
    Dan McEntee

[Air Ministry .]

Note that the same thermodynamics apply to things like nuclear jet engines, where all you have is heat - suck it in, compress it, heat it up, then allow it to expand.

Far Out . Nuclear Stunt . their shouldnt be any noise complaints , and the grass circle wont need mowing either . or does the mutation increase the growth .     

[Air Ministry .]

Was given a kit for the Tiger. ( again ) Then the bloke that gave it to me , was given another !

Theres a old 57 26 in pommy symetrical thin wined one . Pity its not old enough for O. T.

https://aerofred.com/details.php?image_id=103617&mode=search&sessionid=1l3g42r1bmbjsl2f9nuk92p027

You can build the DH 60G III Moth ,with the straight wings ,  from the DH 82 Tiger Moth Kit .
Just redo the cabane to trap the front pilot !



Aerobatics modded de H 82 !

https://s3.eu-west-2.amazonaws.com/abpic-media-eu-production/pictures/full_size_0481/1729177-large.jpg

Though , Kiwi Land , every man and his dog used the for superphosphate .



70 odd the bloke with five in his shed got them for $ 250 to $ 500 . 2000 & another bloke in his shed had five ( All in bits both times ) but now worth $ 250.000 each .
So I figure ' the Govt. ' couldve bought 64.000 Tiger Moths instead of the 75 F-35s for their $ 16.000.000.000 . or 3.200 Spitfires or Mustangs , at 5.000.000 a pop !



I converted mine , control line - to a ' top dresser ' But Flour didnt work well . french Ckalk'd be the go . Or real super . ? You might get this one for $ 150 !

[john e. holliday]

I too love biplanes and twin engined planes.  When I flew the Fokker at the field every body there thought it was great.   I had the SIG Spad back when they first came out that I built for bi-plane combat contest that never occurred.  I still my 38 Special that does a very reasonable AMA pattern.   Maybe when I get the back ailments cured I will get them out just to fly.  Oh, I forgot the Bi-Slob and the Ringmaster Bi-Plane.  Had a Bi-Plane Flite Streak but after about a dozen flights the top wing departed ways.   

[Curare]

Was given a kit for the Tiger. ( again ) Then the bloke that gave it to me , was given another !

Theres a old 57 26 in pommy symetrical thin wined one . Pity its not old enough for O. T.

'59 is the cutoff for MAAA vintage stunt. Get on it!

[Air Ministry .]

Gee . Id looked up the dates , they mustve had it wrong ! . https://stunthanger.com/smf/old-time-stunt-discussion/tiger-moth-26-in-stunt-m-a/  For O T S Tiger ! .