was hurri2d cannons synchronized?

[Citabria]

were the 40mm synched to fire at the same time?

or did one fire and then the other?

in ah one fires then the other making the nose ya back and forth and making all 30 rounds miss.

is this right?

[Makofan]

lol

excellenty put!

[Vermillion]

An interesting question! Wish I knew, maybe Tony will drop in with an answer.

[Staga]

I did check book "Hawker Hurricane: An Illustrated History" by Francis Mason and there were no mention about synchronization.
btw book has a colour scheme of AH's IId "Z-Zebra" BP188 from No.6 Squadron and colour is more brown than it is in AH.

[fats]

Staga,

When ever I encounter the word 'synchronization' ( no I didn't check the spelling ) it makes me think of issues with the propeller. I don't think I've ever seen a mention with any plane book/manual if weapons fired simultaneously, pairs or singleton. Or could that be tuned for example and different planes of same type might have different configurations.


// fats

[AKSWulfe]

I don't think any guns/cannons were synchronized on any WWII planes.

Synchronized to fire through the prop maybe, but they aren't synched to fire together.. but rather to fire when there isn't a blade in the way.

I'd think it would do some evil things to a plane if guns were synched to fire together.
-SW

[cajun]

Good question... But firing guns that big, if they were sychronized it'd prolly rip the wings off

[HoHun]

Hi Citabria,

>were the 40mm synched to fire at the same time?

Excellent question! The Pilot's Notes state that the 40 mm guns were fired electro-pneumatically, opposed to the normal pneumatic system usually employed in British WW2 fighters, so it seems possible.

The benefits would be symmetric recoil without any yawing moment, which could be expected to improve accuracy.

Even for the usual small rapid-fire cannon, synchronized firing would have been beneficial by reducing the recoil-induced vibrations to a simpler oscillation mode (I'd guess :-) In  the Fw 190A-8 for example it would have been possible to fire all MG151/20 cannon at once, but I don't know whether it was done, or even whether the synchronized wing root cannon were synchronized with each other, too. From pictures of a Me 109 calibrating the synchronization system, I'd say at least the cowl guns of German fighters fired each shot simultaneously.

Regards,

Henning (HoHun)

[udet]

aren't the cannons recoilless?

[Tac]

Use Preparation H citabria... shuffling your buttcheeks while firing is not a good combination

[MrRiplEy[H]]

If there isn't any special system to force them to fire one after the other the most logical thing is that they fire simultaneously when the trigger is pressed. With both having the same ROF they should also continue firing synchronically.

[Tony Williams]

Originally posted by HoHun
Hi Citabria,

>were the 40mm synched to fire at the same time?

Excellent question! The Pilot's Notes state that the 40 mm guns were fired electro-pneumatically, opposed to the normal pneumatic system usually employed in British WW2 fighters, so it seems possible.

The benefits would be symmetric recoil without any yawing moment, which could be expected to improve accuracy.
 

Agreed - in fact the guns were generally fired semi-auto rather than full-auto, because firing pulled the aircraft nose down (not too clever when you were a zero feet...) so the pilot aimed and fired both guns simultaneously, one shot per gun at a time.

I have read that the firing mechanism for the underwing NS-37 cannon used by the Il-2 3M tankbuster was not that good so the guns didn't fire quite together, which caused the plane to sway from side to side.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

[Tony Williams]

Originally posted by udet
aren't the cannons recoilless?

Definitely not - but they did have a very long recoil movement which kept the peak recoil impulse down to 20mm levels.

Tony Williams
Military gun and ammunition website: http://www.quarry.nildram.co.uk
Discussion forum at: http://forums.delphiforums.com/autogun/messages/

[Replicant]

Tony, would you agree that the current modelling of the cannons on the Hurricane IID is inaccurate then?  By your description I would say it is; the amount of recoil is extremely severe and virtually unaimable.

regards

[HoHun]

Hi Tony,

>in fact the guns were generally fired semi-auto rather than full-auto

Do you know whether the mechanism was modified, whether the trigger system was modified, or whether it was up to the pilot to time the trigger pull?

>I have read that the firing mechanism for the underwing NS-37 cannon used by the Il-2 3M tankbuster was not that good so the guns didn't fire quite together, which caused the plane to sway from side to side.

I think free-firing guns generally have a strong variation in rate of fire. I've seen one clip with Stomoviks strafing a target where you can see that one moment both wings' cannon fire simultaneously, and the next moment they fire alternatingly. (I don't know the wing gun calibre, though.)

I know synchronization troubles from my latest hobby - stereo photography :-) With Bowden cable triggers, both cameras hardly ever "fire" simultaneously! I've got to think of an electrical system, like in the Focke-Wulf :-)

Oh, about the Focke-Wulf: If I understood it correctly, the electrical priming system requires a pulse generated by the magneto of the Schußgeber to trigger the gun at all. That means the electically primed wing cannon actually have to fire simultaneously with one of the synchronized guns since it doesn't look as if the Schußgeber in the A-8 is the same as in the previous models and doesn't have a special magneto for the wing cannon.

Regards,

Henning (HoHun)