discussion Spitfire aeriolons: How what when why....

[Ian M]

Whislt in the process of chopping the aeirolons (sp) out of the wing on a spitfire, one cant help but notice that the 'top' of it is not at wide as the 'bottom' surface of it.Any one know how that works.

Tried google but there are no pictures that I found that show the control surfaces in opperation.

Any suggestions.

Ian M

 

[Guest]

Ian it is called "Friese ailerons"

The air presure on the lower part of the wing is higher relative to the upper part as you surly know.

The down going aileron will therefore create more drag than the upgoing aileron.This will cause addverse yaw in the oposite direction you want to roll.

To combat this the engineers have made the aleron's leading edge section so that the upgoing aileron's lower LE will sitck out past the bottom of the wing 's trailing edge causing some drag and trying to cvounter the drag from the down aileron.

They also actuate the ailerons to go up more than down minimizing the adverse yaw ,it is called differential ailerons.

If unclear on the explination google the word "friese aileron"

Theuns

 

[Guest]

Adverse yaw - Wikipedia, the free encyclopedia

Theuns

 

[Ian M]

Thanks for that T. However... I was thinking more about the mechanics of them on the Spitfires. I think I can sort of work it out from the explanation you gave and the link.

When aplying up-aileron, the leading edge of the bottom of the aileron will stick out. so the pivot point would have to be around where the top surface of the aileron starts, well a bit bihind it....

Ian M

 

[Guest]

The hindge point can also be on the bottom service but extended into the aileron le by means of a tube. The pivot point would then be on the aileron's main spar tp get the action right

Here is is on the L-18c I built

Theuns

View attachment 24680

View attachment 24681

View attachment 137206

View attachment 137207

 

[PJP]

The Spitfire aileron is a split jobby. When lowered, the top surface remains, it doesn't move.

Also, they have 2 positions only, up and down, unlike the Hurricane which is variable.

When down, they seem to be at a very acute angle, hence the relatively small size.

Hope this helps.

Peter

 

[stona]

The Spitfire aileron is a split jobby. When lowered, the top surface remains, it doesn't move.Also, they have 2 positions only, up and down, unlike the Hurricane which is variable.

When down, they seem to be at a very acute angle, hence the relatively small size.

Hope this helps.

Peter

Peter that's the landing flaps. The ailerons are outboard of the flaps and their action causes the aircraft to roll,i.e.rotate around its longditudanal axis. The rate of roll is one of the most important numbers in a fighter's performance.

I'll leave Theuns to explain the aileron hinges as I don't have any Spitfire drawings to hand. There were several systems and I'm not sure which the Spitfire used.

Cheers

Steve

 

[Guest]

Hi Steve

Unfortionately I have no clue how the spit's ailerons were hindged, I can only assume that it would have been a "cleaner" version of the pix I postet of the Super cub.

Some friese ailerons were hindged on the top , like the plane in the background.It is an Aeronca 11AC I recovered, but these are not as effective as the "standof" hindges, although allot simpler to make.

You might be surprised how bad adverse yaw could be in some planes, a boot full of rudder is needed to get it rolling in the direction you want togo LOL

The ailerons can be rather dangerous if you are flying with a hight angle of attack, near the stall.If the plane drops a wing , the natural thing you want to do is the lift the stalled wing with aileron, however ,this only makes the stall deeper on that wing as the down aileron will effectivly increace the AOA further causing more drag and could lead to a spin..........good times!

This is why we are trained to lift the stalled wing by kicking oposite rudder and leave the ailerons nutral.The rudder will stop the spin force and you then simply fly the plane out of the situation.

I am sure if anyone has pix of the spit's wing from below you will see the hindge extention pionts on it.

Theuns

 

[Guest]

There is this same question covered on Fine Scale Models forum with a diagram of how it works here

 

[stona]

The ailerons can be rather dangerous if you are flying with a hight angle of attack, near the stall.If the plane drops a wing , the natural thing you want to do is the lift the stalled wing with aileron, however ,this only makes the stall deeper on that wing as the down aileron will effectivly increace the AOA further causing more drag and could lead to a spin

Theuns

A problem made worse in a wing with a high loading. Many a Bf109 pilot,even experienced ones,came unstuck exactly like this when landing.

If anyone has the Haynes manual for the Spitfire (I do at home) I'm sure it will show the aileron actuation system.

Steve

 

[Guest]

If anyone has the Haynes manual for the Spitfire (I do at home)

You know.... if anyone else had said that I would have laughed. Somehow I expect it of you Steve lol

 

[Ian M]

Well looks like we got that sorted! Thanks guys you are ammazing!

Haynes manual for a Spitfire. One with wings and not the Triumph i take it LOL.

Have to get me one of those. Book not the car!!

IanM

 

[stona]

Yep,it really exists! It's done in the style of the Haynes manuals for cars as if for a Spitfire owner. It is quite informative with some nice diagrams etc. At the end it even tells you what to do to your Spitfire if you intend to put it into storage lol.

BTW Theuns was quite correct that earlier marks of Spitfire did indeed use Frise type ailerons. Later marks dispensed with this and used a "piano" hinge arrangement to increase the speed at which reversal occurred. Both types dispensed with the fabric covering and were aluminium skinned.

Cheers

Steve