Historum - History Forums  

Go Back   Historum - History Forums > Themes in History > War and Military History
Register Forums Blogs Social Groups Mark Forums Read

War and Military History War and Military History Forum - Warfare, Tactics, and Military Technology over the centuries


Reply
 
LinkBack Thread Tools Display Modes
Old March 26th, 2015, 05:21 AM   #1

ez123's Avatar
Scholar
 
Joined: Mar 2015
From: US
Posts: 688
WWII gyro gunsight


I can imagine how the WWII gyro gunsights could track the direction of gravity, the turn rate, and the roll rate of your own airplane, but the reticule it displayed as an aiming point would have been a line that depended on the range of the target IMO. (Apparently the radar gunsights were not available until Korea?)

So how did that work? I heard a pilot in a documentary mention that they needed to know the actual wingspans of their targets.

I can imagine a reticule that would be a set of upside down V's for different wingspans. Then the pilot could fire when the target's wings appeared to fit in the proper V.

Can anybody enlighten me on the details?

Here is the wikipedia article, but it doesn't explain:
[ame="http://en.wikipedia.org/wiki/Gyro_gunsight"]Gyro gunsight - Wikipedia, the free encyclopedia[/ame]
ez123 is offline  
Remove Ads
Old March 26th, 2015, 05:40 AM   #2

Triceratops's Avatar
Historian
 
Joined: Dec 2011
From: Late Cretaceous
Posts: 2,660
Blog Entries: 2

Found this, if its any help;

The early P-51Ds were equipped with the N-9 sights that were subsequently replaced with the K-14 computing sight that was truly an engineering marvel. this sight also used light projected onto a glass but the comparison stops there. the combination of gyroscopes and magnetic electrical fields in the box considered the speed of the projectiles, the average speed of the target as well as the usual distance between two aircraft in combat, and fed the information to the images reflected on the glass that moved as conditions changed. In other words, the sight calculated a typical deflection that made the pilot's hunting much easier. However, the pilot did have to set a knob to correspond with the wingspan of the enemy aircraft and, using a twist grip on the throttle handle, keep the foe centered in the circle of six diamond images and the center dot. I recall cutting into the cowl with a hacksaw to install one of these sights that was larger than the issue N-9. replacement aircraft came with the K-14 as standard equipment. Every armorer spent a week at an English base near Blackpool, attending school on the sight which was an RAF development.
Triceratops is offline  
Old March 26th, 2015, 05:58 AM   #3

Triceratops's Avatar
Historian
 
Joined: Dec 2011
From: Late Cretaceous
Posts: 2,660
Blog Entries: 2

Here we have the pilot training manual for a K-14 fitted to a Thunderbolt;

K-14 Gyroscopic Gunsight « Lone Sentry Blog
Triceratops is offline  
Old March 26th, 2015, 06:32 AM   #4

Spartacuss's Avatar
mmmmph! mmmMMMMmmph!!
 
Joined: Jul 2010
From: Georgia, USA
Posts: 7,575

Quote:
Originally Posted by Triceratops View Post
Found this, if its any help;

The early P-51Ds were equipped with the N-9 sights that were subsequently replaced with the K-14 computing sight that was truly an engineering marvel. this sight also used light projected onto a glass but the comparison stops there. the combination of gyroscopes and magnetic electrical fields in the box considered the speed of the projectiles, the average speed of the target as well as the usual distance between two aircraft in combat, and fed the information to the images reflected on the glass that moved as conditions changed. In other words, the sight calculated a typical deflection that made the pilot's hunting much easier. However, the pilot did have to set a knob to correspond with the wingspan of the enemy aircraft and, using a twist grip on the throttle handle, keep the foe centered in the circle of six diamond images and the center dot. I recall cutting into the cowl with a hacksaw to install one of these sights that was larger than the issue N-9. replacement aircraft came with the K-14 as standard equipment. Every armorer spent a week at an English base near Blackpool, attending school on the sight which was an RAF development.
Quite so. The N-9 came in two models. The A3 variable, and the B1 fixed.
Click the image to open in full size.

The A3 is on the left. After the A3 was introduced, USAAF units reported their pilots were not using it as intended. They would leave the sight set on zero. Thus the air force installed only the B1 and that was the sight that was replaced by the K-14. Here's the K-14A...
Click the image to open in full size.
Spartacuss is offline  
Old March 26th, 2015, 04:19 PM   #5

ez123's Avatar
Scholar
 
Joined: Mar 2015
From: US
Posts: 688

Thanks, everybody. I have a few more stupid questions.

What is the purpose of the 45 degree angled glass? Is it simply to bend a beam of light projected vertically up from the gun sight in the instrument panel to make it reflect off a point on the windshield? Or did the pilot look at the target through the angled glass? It seems like it might be hard to see through an extra piece of glass?

What were the variables that the gun sights attempted to utilize?
- roll angle relative to level for shooter
- pitch rate for shooter
- airspeed of shooter
- distance to target (via angular size of target and actual size of target)
- expected path of target
- what else?

Did these gun sights work for deflection shots where the path of shooter and target are different?
ez123 is offline  
Old March 26th, 2015, 06:22 PM   #6

redcoat's Avatar
Hiding behind the sofa
 
Joined: Nov 2010
From: Stockport Cheshire UK
Posts: 6,781

The K-14 gyro gun-sight was a US copy of the British Mk II gyro gun-sight.
http://spitfiresite.com/2007/11/mark...-gunsight.html
redcoat is online now  
Old March 27th, 2015, 10:22 AM   #7

ez123's Avatar
Scholar
 
Joined: Mar 2015
From: US
Posts: 688

Quote:
Originally Posted by redcoat View Post
The K-14 gyro gun-sight was a US copy of the British Mk II gyro gun-sight.
http://spitfiresite.com/2007/11/mark...-gunsight.html
Thanks, redcoat.

Another interesting topic would be German gun sights. I read somewhere that the German's studied allied gun sights and decided they were not worth the cost. I assume the Germans had some type of more rudimentary gun sight?

Oh, BTW, I found an explanation of how the K-14 was used. Apparently you entered the wing span of the target. Then you adjusted a dial that resized a set of diamonds until they precisely circled the target. That adjustment told the K-14 the range.

Last edited by ez123; March 27th, 2015 at 10:25 AM.
ez123 is offline  
Old March 27th, 2015, 06:05 PM   #8
Historian
 
Joined: Oct 2009
From: San Diego
Posts: 3,294

Quote:
Originally Posted by ez123 View Post
Thanks, redcoat.

Another interesting topic would be German gun sights. I read somewhere that the German's studied allied gun sights and decided they were not worth the cost. I assume the Germans had some type of more rudimentary gun sight?

Oh, BTW, I found an explanation of how the K-14 was used. Apparently you entered the wing span of the target. Then you adjusted a dial that resized a set of diamonds until they precisely circled the target. That adjustment told the K-14 the range.

Yes. If you adjust the target "circle" to fit the apparent size of the wing as you see it- that tells the instrument how wide an angle is subtended by the wings… if the instrument knows the wingspan of the target, it can tell by that angle how far away the object is and calculate time to target.
sculptingman is offline  
Old March 28th, 2015, 05:24 PM   #9

ez123's Avatar
Scholar
 
Joined: Mar 2015
From: US
Posts: 688

Quote:
Originally Posted by sculptingman View Post
Yes. If you adjust the target "circle" to fit the apparent size of the wing as you see it- that tells the instrument how wide an angle is subtended by the wings… if the instrument knows the wingspan of the target, it can tell by that angle how far away the object is and calculate time to target.
Thanks
ez123 is offline  
Reply

  Historum > Themes in History > War and Military History

Tags
gunsight, gyro, wwii



Search tags for this page
Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
Any USA won war after WWII ? Naima General History 169 September 5th, 2015 08:29 AM
Romania WWII mikhailparaskan War and Military History 88 February 6th, 2014 03:38 PM
Start of WWII Currahee War and Military History 32 November 21st, 2012 02:33 AM
WWII ~+Invisible-College+~ History Help 10 May 19th, 2010 05:21 PM

Copyright © 2006-2013 Historum. All rights reserved.