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Posted
If you want to believe its real time thats fine ...

The only thing i want here is proof. And i see a terminological mess here, we're talking about different things having the same names, like pony is the plane for you and a horse for me.

 

F-15's sight director mode is not what i meant calling GGS a "director sight".

An LCOS sight can give us a valid firing solution based solely on selected range and LOS rate. Because of dynamic nature, it shows us the point at some moment of time. It's the moment for us to shoot now (predict) or for the bullets to hit now (real-time).

So, historical or real-time sight shows us the point where our bullets would be now if we fired them 1 bullet TOF earlier (TOF-1).

Predictor-type sight shows the point where the bullets will be if fired right now (TOF+1).

That's the only difference i meant. Maybe it wasn't terminologically correct enough.

 

As Yo-Yo mentioned, GGS Mk.II and its brothers make valid solution only at constant-G conditions.

There is no difference between TOF+1 and -1 solution in a constant turn. But maneuvers are not very constant, it's normal to operate under changing parameters, and the reason of this discussion is the pipper movement when you, for example, tighten or loosen the stick slightly, or roll accordingly to the target's defensive out-of-plane maneuvers.

 

The most evident difference between TOF+1 and -1 sight type is that when we pull the stick, ideal TOF+1 type reacts immediately, while the "-1" waits 1 bullet TOF before reacting to our motion.

 

What does GGS Mk.II do? It doesn't have anything to wait 1TOF, but its reaction is slowed down and straightened by the gyro's own inertia moment + force applied by the magnets. Which basically puts it somewhere behind the true TOF+1 timing position under variable-G conditions. Get rid of the dampening forces, and it would be a straight TOF+1 type. How much it's dampened, how far it's from there - is a question i'd like to know the answer.

 

If it all is true, then GGS is neither historical, nor predicting under these conditions. However, when you're there, the pipper will always lag behind your movement, and you can get close to TOF+1 solution if you compensate for the pipper lag.

 

except any pilot trained on basic Gyro gunsights is told its not. Even the The F15 in LCOS mode(and we are talking about a far more sophisticated system than a K14) has a Lag line extending aft from the pipper. This in effect represents an analog "time to valid solution"..

If it was a real time sight then the instant the pipper was on should be a valid solution ... its not. Excerpt below from F15 Weapons manual.

OK, looks like it's the process of the same nature. The pipper lags somewhere behind solution.

 

In the PDF some lo res scans (to keep it managable size) from the RAF doc describing the workings of the sight. This is not the full doc. Hope its of some use.

Thank you for this!

I guess Yo-Yo will like it.

  • 3 months later...
Posted

 

you need this:

 

http://www.ibiblio.org/hyperwar/USN/ref/AirGunnery/MARK18GS.html

 

the best explanation out there, from a bomber gunner manual.. pfft...

 

Anybd has fighter gunnery ? the mustang/44 version?

AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS

 

Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.

  • 2 years later...
Posted

I know this is a very old thread but it seems the most appropriate place for K-14 matters (I hate having to search multiple threads for answers on the same subject).

 

For us old-time seat-of-the-pants guys who spurn the Gyro sight in favour of a fixed sight, this may be of interest.

 

Some of us prefer to use the fixed rather than Gyro, for one thing the Gyro often disappears with high deflection shots which we feel we can judge for ourselves, and make, anyway. Also it's easy to get distracted by 'chasing' the Gyro. So, here are some thoughts. All dimensions are given in Imperial units as we are flying an American a/c.

 

A few facts:

The P-51D guns are set to a convergence pattern at 1000 feet (333yds/305m) and cannot be changed (you are flying a standard issue a/c)

The circle of the fixed gunsight is 70 mils (milli-radians) or 4 degrees, therefore at 1000 feet range the fixed circle represents the size of an object (e.g. wingspan) 70 feet across.

70 feet is a typical twin engined WWII bomber. A FW190D-9 is 34 feet wingspan so when it occupies half the width of the ring you are at convergence.

The fixed sight ring is just that, it is fixed in size. This is not very helpful for A-A combat where it would be nice to have a reticule size matched to the target for range guidance.

To use an accurate fixed sight you need to be able to set the correct range and target wingspan.

 

The Range setting should be guns convergence range for maximum effect.

 

The Range dial is graduated in Feet (6 = 600 ft = 200 yds). The other scale on the 'back' of the Ranging dial is in Yards, i.e. 2 = 200 yards, 8 = 800 yards and corresponds exactly to the Feet scale (min 6 = 600 feet = 200 yards, max 24 = 2400 = 800 yards), it's just that I haven't worked out yet how re-adjust that dial to use the yards scale (i.e. rotate it to the front). Perhaps we can't. Maybe it was a Ground Crew option for us Limeys :)

 

So, to use a re-sizeable fixed reticule:

To do this the electrical power must be on and the gyro must be stable and centred - it's possible in flight but easier on the ground.

1. Set the sight range to 10 (= 10 x 100 = 1000 ft = convergence range).

2. Set Gyro motor to Off - set the switch between the Gunsight Mode and Gunsight Dimmer to Off (UP).

3. Turn Gunsight Mode switch to 'Gyro + Fixed' (both fixed sight and Gyro diamonds On).

4. Pull down 'Fixed Reticle Mask Lever' on left hand side of sight about level with the 120 wingspan reading - the fixed gunsight circle and G/A indicator disappear.

 

You now have the Gyro diamonds which will not move around (Gyro motor is off) but can be adjusted for target wingspan at 1000ft range. The Diamond inner points enclose the target wingspan at the set sight range. Now just lead ("leed") the target using your experience :)

 

Incidentally, another explanation of using the moving Gyro sight is here:

http://www.lonesentry.com/blog/k-14-gunsight.html

klem

56 RAF 'Firebirds'

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  • 3 months later...
Posted
i have been playing the aerial gunnery - gyro sight training so the plane is set up correctly, enter 37ft wingspan like it tells me, i never get the piper like in this image.

 

imo it would be nice if those training missions had a third plane that flew a circuit straight and level just to get used to setting the range correctly, labels are in nm and the range dial is in feet and the planes you have to practice against fly more aggressively the closer you get

 

 

Qny6S.png

 

 

you can have your wingman anchor then follow him, he will perform circuits and you can practice on him. would be nice if there was a dummy bullet loadout to not hurt him though...

AWAITING ED NEW DAMAGE MODEL IMPLEMENTATION FOR WW2 BIRDS

 

Fat T is above, thin T is below. Long T is faster, Short T is slower. Open triangle is AWACS, closed triangle is your own sensors. Double dash is friendly, Single dash is enemy. Circle is friendly. Strobe is jammer. Strobe to dash is under 35 km. HDD is 7 times range key. Radar to 160 km, IRST to 10 km. Stay low, but never slow.

Posted

Good article Ivan. Thanks for writing it.

Answers to most important questions ATC can ask that every pilot should memorize:

 

1. No, I do not have a pen. 2. Indicating 250

Posted

How are you supposed to use the rocket ladder on the fixed sight? Is the dot between the angled lines for rockets oe bombs? Is the dot where they'll hit if you launch at x distance, y speed, z angle, and release at w altitude? What do the lines above and below the 70-mil circle correspond to and what are they used for? I can't find much of anything on the air to ground aspect of this reticle, though I suspect there might be some info in the AN 11-35C-1 manual from 1945 for the K-14A. Sadly all I've seen of it so far are a few pictures from people selling pdf's of it on ebay... Forgive me if this is answered somewhere but after a lot of searching I've come up kostly empty.

Posted

About 10 thread below this one you can find this thread Bomb & Rocket Aiming Tipps. Maybe that will help :smilewink:.

When you hit the wrong button on take-off

hwl7xqL.gif

System Specs.

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System board: MSI X670E ACE Memory: 64GB DDR5-6000 G.Skill Ripjaw System disk: Crucial P5 M.2 2TB
CPU: AMD Ryzen 7 7800X3D PSU: Corsair HX1200 PSU Monitor: ASUS MG279Q, 27"
CPU cooling: Noctua NH-D15S Graphics card: MSI RTX 3090Ti SuprimX VR: Oculus Rift CV1
 
Posted

Ya, I saw that thread and watched most the videos. I missed the suggestion of the horizontal bars for the rockets. That was along the lines I used as well, but didn't know if it was proper. I've seen it referred to as a 'rocket ladder' which suggested to me the top, ring, and bottom line might be different steps for range, altitude, or angle, or something. This is the thing I'm referring to - you can find official training material for A-A engagements and what sight picture and alignment should look like, but when it comes to A-G you can find stuff on angles and approach, but not really much on sight alignment and picture.

Posted

That's true. I just went by that thread and practiced some. The rockets fly very straight, as I believe they should, so with a little practice you should get the hang of it.

When you hit the wrong button on take-off

hwl7xqL.gif

System Specs.

Spoiler
System board: MSI X670E ACE Memory: 64GB DDR5-6000 G.Skill Ripjaw System disk: Crucial P5 M.2 2TB
CPU: AMD Ryzen 7 7800X3D PSU: Corsair HX1200 PSU Monitor: ASUS MG279Q, 27"
CPU cooling: Noctua NH-D15S Graphics card: MSI RTX 3090Ti SuprimX VR: Oculus Rift CV1
 
  • 1 month later...
Posted (edited)

Should be a radius of 50mil based on this material of the K-14:

 

EynscO3.jpg

 

If that's correct one can apply easy range measurement.

 

size/range = SizeInMil/1000 -> (size * 1000) / SizeInMil = range (from Wiki)

 

With usage of 100mil sight that gets pretty easy.

 

(size * 1000 * "how many times AC fits in circle") / (100mil) = size * 10 * "how many times AC fits in circle"

 

2x 10m-AC fit in circle? -> 2 * 10 * 10 = 200m

3x 20m-AC fit in circle? -> 3 * 20 * 10 = 600m

 

Pretty simple :)

Edited by Zabuza
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